Burgundy: The History of the Vignerons: The Villages part I

The wine villages of the Côte d’Or in the 18th Century

By Dean Alexander

PommardReflecting on it, I find it amazing that the descendants of so many old Burgundian families still farm the vineyards, and live in the same tiny villages of the gold coast as their ancestors. Many of these families have lived there for more than two centuries. The Roty’s of Gevrey-Chambertin arrived there in 1710, and have now lived in Gevrey for more than three centuries, and the Mongeard family arrived in Vosne in 1620, just shy of four centuries.

Consider further, for many generations, all but the most wealthy, rarely traveled much farther than the fields that they worked, none of which were very far away. They often did not know the families from two or three villages distant, because to get there, many of them would have had to walk. They lived and died in the houses in which they were raised, and that was often the same house that their mother or father was raised.(1) For most urbanites, this is kind of stationary life is unfathomable. But this long history of a family being precisely in a single place, for so many generations, can only be explained by these people having developed exceptionally strong emotional ties to their village, their family, and to their land.

While to outsiders, the daily life of the farmer can only describe as repetitious and mundane, in the long view, the changes that have occurred on the Côte can be fascinating. Over the span of the past two to three hundred years, these fermier families have had, along with a certain amount of luck, the ability to adjust and adapt at crucial times.

First and foremost, they were lucky. To have had built up enough assets to handle disasters as they came can be a matter of luck. Any ship can sink in the perfect storm. But beyond that, they tenacious, yet flexible enough to endure nature’s worst. Examples of adversity the families of the Côte would face included: multiple, several near-total harvest failures, and more than a couple vineyard losses due to vine killing winters, hail, and flooding. Then there were the major diseases such as mildew (oidium in 1854 and downy in 1887) not to mention phylloxera.

The image of a peasant girl resting, is from the Paris Salon circa 1893.

The image of a peasant girl resting is from the Paris Salon circa 1893.

The political and economic challenges were relentless, included the lengthy French Revolution, multiple governmental changes, and economic and the catastrophes of wars and occupation. Had these families not been lucky, not had assets when they needed them, and not made the right decisions at the right time, they would have left been forced to leave, as many did. (Garnot 2008) Most importantly, they had the ability to make the jump from being simple paysans, meaning the peasant-farmers, who only just subsisted on small plots land, to fermiers who not only owned the land they worked, and more importantly, owned enough land they needed to hire people to help work the land they owned.

Gone from the Gold Coast now are those paysans.  Their small plots absorbed by larger landholders and their labor replaced in the fields professional vineyard managers and workers and supplemented day laborers.

Throughout the late 19th and most of the 20th century, it was an idealized version of these very peasants, who had been economically pushed out of the Gold Coast, by which the French viewed their own national identity.  The French viewed itself as the peasant: a stout, strong, determined, rural proletariat, who farmed the land, feed the nation and were called to war. (Lehning 1995) It was generally felt that the peasants were the backbone of the country. As such, it was with a certainly irony, that much later, during the 1920 and 1930’s, the fermiers of the Côte would begin to market Burgundy and themselves as synonymous with the already existent folklore of the ‘peasant farmer’. (Whalen 2009) This would be their guarantee of quality, their simple honesty, steadfastness, and hard work.

 

print of Gevrey Chambertin from Dr Jules Lavalle's 1855 Histoire et Statistique de la Vigne de Grands Vins de la Côte-d'Or

print of Gevrey-Chambertin from Dr. Jules Lavalle’s 1855 Histoire et Statistique de la Vigne de Grands Vins de la Côte-d’Or

The growth of a village

In an isolated locale, like the wine villages of the Côte d’Or, a census is a very good barometer of the health of its economy. As the economy heats up, as financial folks like to say, the population increases. Conversely, as the economy slows, populations tend to contract accordingly. In 1793, toward the end of the Revolutionary period, the first census of the new republic was taken.  At this time, the population of Gevrey was only 1,193. Over the next two decades, Gevrey’s population would grow only incrementally until 1831, when it would begin to expand over the next 50 years.

Phylloxera, in its steady march across France, would finally reach the vineyards of the Côte d’Or in 1880. However, rather than the loss of production forcing the population to contract, -as those “in the margins” were indeed displaced by a lack of field work, new inhabitants were arriving, largely replacing their numbers. A whole new industry had sprung up surrounding the fighting of phylloxera. As that battle was gradually lost, these jobs would eventually be replaced by those who would plant the vineyards again. These were people who had trained in the new skills of grafting vinifera Pinot and Chardonnay vines to the hybrid American rootstock. This carousel of workers kept the number of people living in the village fairly constant, but generally, the fermiers, the landholding farmers, many whose family names we recognize today, remained.

The census of 1881 revealed a population of 1,868. Shortly after the turn of the century, economic instability, and low wine prices, and falling vineyard values, would cause the lowest number of inhabitants since the census had begun, with a mere 1,543.  Gevrey’s population would fall even further during the interwar years, for in 1936 Gevrey had a population only 1,486, the lowest it had been after one hundred years of growth. These were grim times, and the fermiers and concerned politicians sought new ways to produce and market wine independent of the negociants that had controlled the industry since the 1750’s. These efforts, coupled with the Europe’s general economic recovery after the Second World War, has sent the population dramatically upward, with new industries which supported the now profitable wine growers and bringing with them hundreds of new jobs. The censuses of 1962 and 1975 marked how dynamic the recovery had been. (census figures: fr.wikipedia.org)

Population of GevreyThe population of the larger town of Nuits-St-Georges, a center for negociant trade in the mid-1700‘s, has been more stable than Gevrey. Nuits expanded through pre-phylloxera times but then remaining fairly steady for almost a century between 1866 and 1954. The town’s population saw minor fluctuations of alternately adding and losing 100 to 400 people, through the end of the Second World War, but these changes were a much smaller percentage of the population than the swings seen in Gevrey-Chambertin. This is likely that because of the town’s size, there was far more business operating in Nuits-St-Georges beyond the direct cultivation of the vines. As an overview: in 1793 Nuits had 2,541 inhabitants. It peaked just before phylloxera 1881 at 3,727 people. Today, after steady growth since the end World War II, (3,285 in 1946), the population now sits at 5,516 in 2008. (fr.wikipedia.org)

Stepping farther back in time

The old villages, tranquil wine smaller villages of the Côte d’Or, with their narrow streets and quaint houses, are quite easy to envision two hundred fifty years ago, during the time of King Louis the XVI, for these are remain small, sleepy, villages. Vosne even today has a population of a mere 427 people, and only 307 people live in the nearby village of Chambolle. Even with the tourists that mill around and support the restaurants and inns of the old, more touristy section of Gevrey-Chambertin, this section of town could not be described as bustling. It would seem as though place must be quite unchanged over hundreds of years. In your mind’s eye, just exchange the slow trod of oxen pulling a cart along the graveled highway for the cars that now ply the paved RN74.  Upon the once cobbled streets of the better sections of the village, add in horses and the staccato of their hooves. Wood-smoke, billowing from the chimneys of a few dozen open hearths; the day crisp, with fall in the air, and the vision should be complete.

But things have changed in these villages. Perhaps the biggest paradigm shift took place when the vines of Pinot Noir won out over Gamay.

(*) larger is relative, but considering the value of the land, and the wine made from it, these are not poor men. (**)The increase of population in the larger towns and villages is best explained by more wealth is created by both vignerons and by the tourist industry, the there are more jobs available to service their needs today. 

 

French peasants depicted in "Fin du Travail" by Jules Breton (1887)

French peasants depicted in “Fin du Travail” by Jules Breton (1887)

Economic battle between of Pinot Noir and Gamay

Winter 1709For many centuries, there was an economic and ideological battle going on between those who were planting the vines that produced the more consistently ripening Gamay grape, and those who would have all vines in Burgundy planted only to Pinot Noir.

For some, the battle was societal. While certainly it was recognized that Gamay could produce a high-tonnage of fruit, while still maintaining acceptable quality (for the masses), the noblesse d’épée (noble of the sword), the noblesse de robe (magistrates and parliamentarians of Dijon), clergy officials, and most acutely, the invested haut bourgeoisie, felt the Gamay wines were coarse and undeserving vineyards of the Côte d’Or. Most importantly, they rightly felt Gamay pulled down the reputation of the Côte in general. Gamay certainly did not add to the noble reputation that the upper strata of society believed the region should be allowed to attain.  Social standing and reputation in the 18th century was hugely important to those in a position to affect it, and cannot be underestimated in the context of where some Gamay should and should not be planted in Burgundy.

For centuries there was a vocal pressure to eliminate Gamay, and although it was banished by Philip the Bold in 1395, peasants continued to grow on the slopes through the end of the 19th century. In Morey“Of the 160 hectares under vine,” Auguste Luchet wrote in 1858, “90 are planted to Gamay.” Later in the text, he would write: “Gevrey has about four hundred hectares of vineyards, half in Gamay and one in Pinol (Noirien) mixed with a little white.”

According to Marion Fourcade, an associate professor at UC Berkeley, there were “periodic local ordinances” eradicate Gamay in vineyards of the Côte d’Or. In her paper,“The Vile and the Noble” (2012), Fourcade briefly mentions that those who pushed to expunge Gamay alleged its cultivation promoted various unspecified “health dangers”. As an economic problem, Gamay’s critics charged that its cultivation contributed to an increase in the fraudulent bottling of Gamay as Pinot Noir, or alternately, it was accused that Gamay was illegitimately blended with Pinot Noir. This no doubt occurred. But, as previously believe in the preceding centuries, Gamay was, in general, unworthy of the region.

LavalleDr Jules Lavalle, in his 1855 book, “Histoire et Statistique de la Vigne de Grands Vins de la Côte-d’Or, which was revered by many, calls Gamay “common,” and “ordinary,” claiming Gamay had “invaded hilltops and flatlands all around”. (Forcade 2012)   “God knows how awfully active the vulgar plant has been in driving away the fine plant, and what progress it makes every day! Our ancestors would have been appalled!” As translated by Fourcade.  In Charles Curtis’s translation of Lavalle (in which I did not find the aforementioned quote) in his book the “Original Grand Crus of Burgundy”, Lavalle writes “The vines planted in Gamay cover more than 23,000 hectares,(1) which one meets under the name of plante Mâlain,  plante d’Arcenant plant de Bévy” Additionally Lavalle condemns that “The yield can often extend to 50 and even 60 hectoliters per hectare.”

The choice to plant Gamay was surely decided, however, not by the ideological mindset, or by social consciousness, but rather by the wealth of the vigneron. The poor farmer could simply not afford the high-stakes gamble of Pinot Noir presented, with its pitifully small production of 18 hectoliters per hectare (Lavalle 1855), and its inability to consistently ripen its fruit completely  The peasant could not afford a single failed vintage, that the high-risk Pinot Noir grapes delivered this result on a fairly consistent basis.*

Moreover, Pinot, with its thin skin was particularly prone to rot and disease, it was far more difficult to make into a competent wine. In some years, Pinot vines would produce a completely unsalable crop. The wealthy landowning farmer (a fermier – as opposed to a vigneron) could take such a gamble with virtual impunity, because when it the Pinot crop paid off, the dividends of producing a great wine, far outstripped the losses incurred by poor to very poor vintages. The incredible demand (and payday) for wines from great vineyards, in these great years, continues to this day.

(*) It is not without note that the little ice-age, (which dates are contested) is generally thought to have begun in the 1300’s, and ended around 1850. Additional weather variations occurred, with extremely low temperatures materializing with disastrous effect in 1660 1709, 1740 and 1794/1795 and the last in the year 1850.

Grains are still a major crop in the Cote d'Or

Grains are still a major crop in the Côte d’Or. Here, adjacent to vineyards that produce Bourgogne Rouge on the outskirts of Gevrey, wheat, rye, corn and barley are regularly planted and harvested. photo googlemaps.com

The paysan of the Côte, a poly-cultiveur

While we think of only vines on the slopes of the Côte d’Or, the vineyards of the early to mid 18th century, were typically a polyculture. It was common for the vines to share the slopes with animals, fruit trees, and vegetable plots, depending on the site. (Swann 2003) However, as the 18th century progressed, economics would begin to crowd out polyculture off of the slopes.

Below the vines of the great vineyard slopes, upon low-lying fields, grew all manner of foods, particularly grains. Rye which grew well on the poor soils of northern France, corn, wheat and barley were widely grown; and in personal gardens next to their houses, the peasants often grew vegetables. It is well documented that the lower third of Clos St-Jacques was planted to alfalfa until 1954, but it is likely that it had been home to many different crops over the centuries.

Very few ‘vignerons’ during the 18th century actually worked solely with the vine, and those that did, according to historian Benoit Garnot, were in decline in the 18th century. He laments bleakly that “the tired qualification ‘winemaker’ seems to be socially rewarding.” (Garnot 2008)

Busby wrote, in 1840, that in vignerons in Chambertin would rip out dying provignage vines (which only survived ten years or so), and let the land fallow while being planted to sainfoin, a cover crop that flourishes on calcareous (limestone) soils. Planting sainfoin had dual benefits: it not only would the crop rejuvenated the topsoil with an infusion of nitrogen but it also the sainfoin was a good feed for their grazing animals. Those vignerons that had a cow or two, had them tended by a communal herder who took them to field for the day and returned them to the owner at night.

Jean-François Millet (1814-1875), Vineyard laborer resting, 1869

Jean-François Millet (1814-1875), Vineyard laborer resting, 1869

The fall harvest season was unrelenting and well-reported as being extreme in the exhaustion it created.  By the end of August, all of the rye, which was an important crop in the poor soils of north-eastern France, and the summer wheat, had already been harvested. Also already harvested were the other major crops, which included barley, colza, which is also known as rape, or rapeseed, was grown for lubricants, and hemp  (not to be confused with its relative cannabis), was also grown for seed, oil, wax, resin, rope, cloth, pulp, paper and, in this north-eastern region. (U.S.Gov. Printing Office 1888) This would give the paysan a month for the grape harvest, before the planting of winter wheat, which would begin straight away in October, after pressing and barreling of the new wine.

Centuries of stagnant agricultural practices

It is widely accepted that during the ancien regime, few improvement in farming had come to France. The tasks of the cultiveur were done in the least expensive manner; just as their fathers and grandfathers, and as well their great-great grandfathers had farmed the same land.

To the English agronomist Arthur Young, who visited Burgundy and elsewhere in France on the eve of the revolution, the inefficiencies of French agriculture was “quite contemptible’. He was so critical of French farming methods as to say that even the large capitalist farms were “villainous cultivated’. As far as investing in capitalization farming given the French methods, he declared “If I had a large tract of this country, I think I should not be long in making a fortune’.(Swan 2003)

Change was painfully slow, despite attempts by Dijon to push the people to adopt them. The problem really came down to money, and the peasants had none to invest in the changes necessary. A Burgundian representative to the National Constituent Assembly, during the first stages of the Revolution, explained the failure of previous attempts at agricultural reform:

“Oh you who complain of the intractability of the peasant when he refuses to adopt your new ploughs, your new seed drills…your deep furrows, your doses of fertilizer that are four times greater than what he can afford, before tripling his expenses in the uncertain hope of a tripled harvest, begin by putting him in a state of being able to buy clogs for his children.”

 

wheat fields Van Gough

 Up Next: The Villagers of the 18th Century

 


Additional Notes:

(1) Life was short and death rates of children under the age of ten were high. Because of this, and the general lack of excess money homes traditionally multi-generational. There will be much more about life and death on the Gold Coast in upcoming chapters.

(2) Charles Curtis, in his book “The Original Grand Crus of Burgundy”, takes these hectare figures, printed in Lavalle, at face value, and proceeds to discuss how they might be accurate. However, I feel, that they are as just as likely, a misprint,  so far off from the hectares, as they exist today, even taking into consideration the loss of so much vineyard land, post-phylloxera, that was never replanted around Dijon. One might also view these figures to be considered a fabrication, as a call to action against the Gamay scourge. Words are weapons. Because there appears to be no other at the ready figures of Gamay and Pinot Noir acreage planted in the Cote d’Or to compare Lavalle’s figures with, I choose to bypass the issue altogether. It isn’t all that germane enough to the already too wide of a scope of these writings, to deal with something I can’t bring to an adequate conclusion about. There are other fish to fry.

 

 


 

Reference Sources for Burgundy: History of the Vignerons: The Villages parts I – IV 

La Côte-d’Or à vol d’oiseau: lettres écrites à M.L. Havin, après la récolte, Auguste Luchet 1858

Gevrey-Chambertin: notice historique, topographique et statistique, suivie de promenade à Fixin, by Henri Vienne 1850

Journal of a Tour through some of the vineyards of Spain and France, James Busby, Sydney 1833

Peasant Proprietors and other selected essays,  Lady Frances Parthenope Verney Longmans, Green, 1885 –

L’état de la recherche sur la vigne, le vin et les vignerons en Bourgogne au XVIIIe siècle, Benoit Garnot,  2008

The Peasants and the King in Burgundy, Hilton Root, University of California Press, 1992

Evolution du Métayage en France, L. Durousseau-Dugontie, Impr. Crauffon, 1905

Centre d’Histoire de la Vigne et du Vin, Charlotte Glain-Fromont,  Bulletin de liaison Bulletin 30 janv-fev 2012.pdf

 LES Climats du vignoble de Bourgogne Dossier de candidature à L’INSCRIPTION SUR LA LISTE DU PATRIMOINE MONDIAL DE L’UNESCO Janvier 2012

Communities of Grain: Rural Rebellion in Comparative Perspective Victor V. Magagna Cornell University Press 1991

Infant and Child Mortality in Eighteenth Century France: A Function of Income? Hajime Hadeishi,  Bureau of Economics Federal Trade Commission, cliometrics.org 2010

Harvest Failures, Jennifer Llewellyn and Steve Thompson, 2015 Alphahistory.com

Cattle and Dairy Farming Part 1 United States. Bureau of Foreign Commerce  U.S. Government Printing Office, 1888 –

The Peasantry in the French Revolution P. M. Jones, Cambridge University Press, 1988

Peasant and French: Cultural Contact in Rural France During the Nineteenth CenturyJames R. Lehning Cambridge University Press, 1995

Insofar as the ruby wine seduces them’: Cultural Strategies for Selling Wines in Interwar Burgundy,” Contemporary European History 18.1 Philip Whalen (2009)

The Vile and the Noble: On the Relation between Natural and Social Classifications in the French Wine World, Marion Fourcade,  Sociological Quarterly 2012

Aristocracy, Antiquity, and History: An Essay on Classicism in Political ThoughtA. A. M. Kinneging Transaction Publishers, 1997

Encyclopedia of the Enlightenment By Michel Delon, Routledge 2013

Provincial Power and Absolute Monarchy: The Estates General of Burgundy 1661–1790 Julian Swann, Cambridge University Press  2003

History and Climate: Memories of the Future? Phil D. Jones, A.E.J. Ogilvie, T.D. Davies, K.R. Briffa Springer Science & Business Media, Apr 17, 2013

The Decline of Childhood Mortality Kenneth Hill. Department of Population Dynamics School of Hygiene and Public Health Johns Hopkins University 1990

The Discovery of France: A Historical Geography Graham Robb W. W. Norton & Company2008

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Understanding the Terroir of Burgundy: Part 4.1 the history of erosion, defense, and restoration

Erosion and man

 

Historical vineyard defense and restoration

 

During the late 1990’s and early 2000’s, soil measurements in both Vosne-Romanée and Corton determined that the erosion rate for both areas were approximately 1 mm per year. Considering that the entire Vosne hillside, as well as all of the hill of Corton are either premier or grand cru sites of enormous value, one would have assumed that every effort had been made to limit erosion. But that assumption would not have been completely true.

 

Even now, 15 years later, with ever-improving an information, and a growing acceptance that erosion is significant problem that needs to be further addressed, not every farmer is making the necessary changes. While soil management may not be ideal in every plot, vast improvements have been made from the time of the Middle Ages, when erosion ravaged vineyards of the Côte d’Or.

One of Vogue's parcels of Musigny denuded of all grass. While there is no denying the quality of the wine today, what of the vineyard in the future? photo: googlemaps

One of Vogue’s parcels in Les Musigny, denuded of all grass. While there is no denying the quality of the wine today, what of the vineyard in the future? photo: googlemaps

Man has waged an epic war against erosion for centuries; which, until recently, has been largely futile. The early Burgundians were understandably ignorant of soil structure and proper tillage techniques, both factors that greatly mitigate erosion. They had no way to know that it was the way they farmed that actually caused the huge erosional problems they fought so unsuccessfully to reign in.

Change, in an old, tradition-bound culture is resisted; and that is nearly as true in Burgundy today as it was in the middle ages. New techniques such as conservation tillage can be very slow to be adopted, much less having a discussions with older generation about whether a vineyard should be tilled at all. That this ancient practice of zero tillage has been implemented with success in other areas as long ago as 1971, is of no consequence.

Many farmers still restrict the growth of ground cover by use of either pesticides and or routine tilling, both of which diminish soil structure and increase exposure to erosional factors. This can be seen even in Comte de Vogue’s perfectly neat parcels of Les Musigny, where only a few tufts of grass evade the plow blade or the hoe. While it is difficult to argue with Vogue’s results in the bottle, the unseen menace of sheet erosion exists robbing the soil of fine earth fractions, ever so slowly.(1)

Before global warming, the vines were planted in Burgundy in east-west rows, straight down the slope. This directional planting was done in belief that it opens the vines to the early morning sun, allowing better ripening. Unfortunately, any truth to this is offset by increased erosion. While the weather was often predictably cold, and complete ripening could be hit or miss, the soil is a not a renewable resource. As we examined in Part 4, soil lost over 6,000 years ago from the hillsides of central France at the hand of Neolithic men, still has not, and in all likelihood, will never really repair itself.

Burgundy’s historical defense of the vineyard

flooding gate

photo: Caroline Parent-Gros

Murgers, or stone walls, have historically been the farmers first, and perhaps only, line of defense since antiquity.  Murgers (or Clos if the wall completely surrounds a vineyard) as part of the idealized visage of Burgundy, shows itself as part of many vineyard’s name, ie. Volnay Clos des Chênes or Nuits St-Georges’ Les Murgers.

Most murgers were no more than stacked stones constructed from rock that had been removed  from between the rows of vines because they were plowing obstacles. Stacking them into walls to protect the vineyard from erosion naturally evolved in the fields. In the 18th and 19th century, some of the more wealthy landowners began to have murgers constructed from brick and mortar, then covered with a fine glaze of lime plaster.  Grandiose entrances to these murgers were hung with intricate iron gates, meant to indicate both the importance of vineyard, and the owner.  In either the case of a stacked stone wall, or a much more extravagant Clos, walls have been the leading defense the vineyards for centuries. They not only serve to direct runoff around the vines, also have the equally important function of keeping the soil that is in the vineyard from being carried out.

Folatieres wall

 

Vineyard reconstruction in the middle ages

It is now widely understood that the simple act of farming causes erosion, and poor farming techniques can cause tremendous erosion, particularly on slopes. The earliest record of man’s attempts to fix the vineyards eroded to the point where they could no longer support vines, comes from documents kept in the later Middle Ages.

Jean-Pierre Garcia, a noted scholar at the Université de Bourgogne, quotes manuscripts in which detail the fight against erosion 600 years ago, in his paper “The Construction of Climates (Vineyards) in Burgundy during the Middle Ages(from French). Translating these ancient texts from the French of the Middle Ages into modern English is challenging, but the message these manuscripts contains is clear: fighting erosion was back-breaking and exceptionally expensive, despite the luxury of cheap labor. This work was likely paid for the Dukes of Burgundy or the Church, or on possibly a smaller scale, by the Duke’s seigneurs, noblemen whose the manors covered Burgundy.

Murgers in Vosne

click to enlarge. photo: google maps

The accounts are as such: In Corton in 1375 and 1376 AD, 38 days of work were required to remove a drystone wall that had collapsed “in the vine” and rebuild it “four feet high along the vine Clement Baubat to defend of acute coming from the mountain.”  In Volnay, it was written in 1468-1469, that men had to excavate the earth below the Clos which had eroded down to rock, and “lifted from earth” returning the topsoil to the vineyard. In 1428 there is a reference of constructing a “head” “above the Clos Ducs Chenove for the defense eaues to descend along said cloux.”

By the end of the middle ages, there are the first references to “exogenous inputs of land”, meaning that earth is brought in from an outside area to replace the topsoil lost to erosion. Land was taken in 1383 from Chaumes des Marsannay and from below the “grand chemin” (highway). This was a huge undertaking that was completed over the scope of “691 workers demanding days”.

Horses and wagons were very expensive in the middle ages. Having 800 wagon loads plus the labor was a major undertaking.

Horses and wagons were very expensive in the middle ages. Having 800 wagon loads plus the labor was a major undertaking. This, a woodcutting from 1506 depicts the power associated with the horse-drawn cart, is called “The Triumph of Theology”.

Then again in 1407 through the spring of 1408, it took 128 days of work were “to flush the royes and carry the earth in the clos,” and 158 working days “to bring the earth into the Clos.” It is immediately obvious that medieval French measure was unique to the time, and is very difficult translate. In one instance, it was recorded that for 28 days carts carried earth into a vineyard in Beaune, and “28 days labor and 48 days working.” In 1431 there was this reference that “six days a horse hauler, dumped 30 days to 2 horses (are needed to dig from) the Chaumes de Marsannay and the road beneath the Clos where piles of earth were raised.” While the exact labor is impossible to gauge, it is very apparent that immense effort was made, by whatever means necessary to return the vineyards of Burgundy to agricultural viability.

Here rill erosion has stripped the soil down to the limestone base in Corton-Charlemagne. photo from an excellent study by  J Brenot et al of the Segreteria Geological Society in Rome.

Here rill erosion has stripped the soil down to the limestone base in Corton-Charlemagne. photo from an excellent study by J Brenot et al of the Segreteria Geological Society in Rome.

The practice of bringing in soils from outlying areas continued through at least through the 18th century. When the RomanéeConti vineyard (a national property) was sold in 1790, the sale documents reveal that in 1749 the “Clos received 150 carts in grass taken off the mountain” of Marsannay.

1785-1786 “dug near the bottom of the vineyard and removed 800 wagons of earth, and this was spread in areas devoid of ground and low parts.”  This practice appears to have ceased, or as Garcia writes “at least on paper” after 1919 when the Appellations of Origin was established. The INAO has certainly forbidden exogenous soil additions since it was formed in 1935.

Interestingly, while on the subject of Romanée-Conti: some of its soils are clearly foreign to the Vosne-Romanée, according to geologist Francois Vannier-Petit,  a void appears in the substrata of the south-western corner of RomanéeConti  which suggests the hillside had been quarried at some point, and filled in with “exogenous” landfill. James E. Wilson noted this void as well in his book Terrior (p 137), where he notes that seismic data suggest this void was created by a fault, but electrical resistivity data suggest an erosional scarp (meaning ancient erosion created a cut out in the hillside) into what Wilson identifies as Ostrea acuminata marl below. Wilson, in either case, assumed that subsequent gravitation induced rock slides and erosion from above filled the void with colluvium. Any of the three possibilities are viable explanations, but the manuscript from the  1785-1786 do clearly state 800 wagons of earth” were “spread in areas devoid of ground and low parts.”

The issue of a quarry in Romanée-Conti is far from clear cut. click to enlarge. photo googlemaps

The issue of a quarry in Romanée-Conti is far from clear-cut. click to enlarge. photo googlemaps

At this point, no record has been found regarding a quarry having been excavated at the site of RomanéeConti, but many governmental and clergy records were destroyed during the revolution. With this, the argument that these vineyards have “special dirt” has been laid open as fallacy. The topsoils of the Côte have been reshuffled for centuries, integrating alluvial loams and clays from the base of the slope (or from elsewhere) back into the fold of the upper slopes of the Côte d’Or. The vignerons of Marsannay who are lobbying for 1er cru classification for their vineyards would certainly point to the fact that their dirt is very similar to the dirt in Gevrey. Better yet, it is clear that a fair amount of Marsannay dirt contributes to create RomanéeConti, the greatest wine all of the Côte d’Or, and that dirt has been there for centuries.

As if by divinity, the some potential erosional problems were avoided by the fact that Burgundy’s vineyards tended to be quite small. Murgers at vineyard boundaries could then slow the velocity of the runoff as it moved down the hillside, not allowing it to gain so much momentum that a high suspension velocity can be reached. These vineyard breaks have been crucial in even wider erosional damage in many areas.

The creation of small vineyards was often caused by two factors. The first being economically large vineyards did not make sense. There wasn’t sufficient demand for wine to produce significantly more than the greater Burgundy area could consume. The poor roads and the lack of safety between villages and cities made medieval trading slow and perilous. Additionally the division and subdivisions of France and the rest of Europe meant that lords had the right to restrict passage and to impose fines and tariffs upon merchants.  These factors diminished the volume and frequency of trade within the continent, and in turn limited the amount of wine needed to be produced. Large tracts of vineyards were not necessary. The second, and perhaps the greatest limiting factor of vineyard size would be size of a plot that a single man could work in a day.

Les Glaneuses (1857) by Jean Francois Millet

Les Glaneuses (1857) by Jean Francois Millet

While ouvrées simply means worked in modern French, it was used in the past as a measurement of land based on how much land a single farmer could work himself.  Thus, one ouvrées (4.285 ares (2) or a tenth of an acre) is the amount one man can work in one day without a horse.  Madame Roty re-counts her family’s history in explaining that in the late 1800’s an earlier generation did not bother to plant their vines in rows since they could not afford a animal.

This suggests an interesting fact set of circumstances. Before the Revolution, (the Roty’s farmed Gevrey since 1710) farmers who specialized in grape cultivation, worked a handful of parcels on the local Seigneur’s manor, in the open field system described in Part 4. In this feudal society, they had the use of a shared horse and plow which belonged to the estate. However, after the ownership of land was released to the serfs following the Revolution in 1793, they may have now owned their parcels, but they so poor they could not afford the animals to farm them. This forced most of the peasants of Burgundy use to no-till farming methods. Later as economics of the region improved, a horse could be bought (perhaps in co-op one with one or more families), the Roty’s were forced to remove some of the vines so the animal and plow could pass through.

Farmers who could afford a horse, found the animal multiplied their efforts eight-fold, allowing them to plow 8 ouvrées in a day.  A family with a horse could now manage seven hectares of land, which were, of course, divided into the same feudal era parcels families of the area had always farmed, just as they do today.

The emergence of tractors opened up the capabilities substantially more, allowing growers to farm much larger areas of land. Additionally that extra time has allowed growers to farm in farther flung vineyards, in villages outside of their own.

 

Next Up: Part 4.2 Erosion fundamentals: infiltration rates, runoff and damage, and how it has changed the wines of Burgundy.

 

 


(1) Musigny has three factors in its favor. It has a shallow slope which aids in its soil retention.  It is a shallow vineyard, in that its rows are not long, and runoff can not achieve a high suspension velocity. And third, it is enclosed by walls that help protect it from some erosional forces.

(2) Ares is 100 square meters, and a hectare is 100 ares.

 

 

Understanding the Terroir of Burgundy: Part 3.4 The Grand Crus

 By Dean Alexander

While working my first wine shop job twenty years ago, I asked the store manager – who was a Burgundy guy of significant reputation: “Why is Rousseau’s Ruchottes-Chambertin not as good as as his Clos de Bèze and Chambertin?”  The answer I got was honest: “I don’t know. I’ll have to ask next time I’m there.”

It years later that realized that I had asked the wrong question. The question I should have asked was: What causes these neighboring vineyards to produce wines of such different character? 

Today, twenty years later, I can answer that question. If you have read my previous 12 articles in this series on Understanding the Terroir of Burgundy, it is likely you can answer it too. More importantly, some of the lessons here can be used to understand other appellations where less concrete information is known.

Clos des Ruchottes to the right, and Ruchottes du bas, on the left. photo: googlemaps

Clos des Ruchottes to the right, and Ruchottes du bas, on the left. photo: googlemaps

The short answer

Chambertin, Chambertin-Clos de Bèze, and Ruchottes-Chambertin

These three grand cru vineyards sit in a row, shoulder to shoulder on the same hillside. All have their upper-most vines smack up against the forested hillside, and all have virtually the same exposition. The legendary domaine of Armand Rousseau farms and makes wine from all three of these vineyards; yet one, the cru of Ruchottes-Chambertin, does not seem to be cut from the same cloth. The wine made from Ruchottes is not as rich or opulent. It tends to be lighter, more fine-boned, and more angular in its structure. The primary reason for this difference in wine character is that right at the border of Clos de Bèze and Ruchottes, the limestone beneath changes significantly. Unlike the other two vineyards, Ruchottes-Chambertin sits over very hard and pure limestone that is composed of almost completely of calcium carbonates and very little in the way of impurities, such as mud or clay.

The impurities within the stone, (bonded by the calcite) is what determines how much clay and other materials will be left behind as bedding materials when the stone has weathered. The more impurities in the limestone, the more nutrients will be available for the vines when the stone weathers chemically.  Further, it will reflect not just how fractured the stone has become due to extensional stress, but it will have often been the determining factor of whether the bedding has become friable as well. The wines of Chambertin and Clos de Bèze have this sort of impure limestone as a bedding under three-quarters of its surface area. It is a significant factor in giving the wines of Chambertin and Clos de Bèze a heavier weight and richer character than the wines from Ruchottes.

Another major factor in this differential in wine weight is that Ruchottes is a much smaller appellation, which confines it solely to the upper-slope. Its location makes it subject to all of the factors that challenge upper slope vineyards, details that are examined in Part 3.3.  Conversely, both Chambertin or Clos de Beze extend almost three times farther down the hill, all the way to the curb of the slope. Additionally, while the degree of slope may kick up in the upper final meters of the Clos de Bèze and Chambertin, the area under vine upon upper slope (that will produce a lighter wine) is relatively small compared to the entire surface area of those vineyards.  

Unlike Ruchottes, the long slopes of Chambertin and Clos de Bèze will reach down to almost to where the slope completely leveled off. There at the base of the slope, rock and soil colluvium will have been transported by gravitational erosion, adding generously to the depth the soil. This depth allows more water to be absorbed and retained for use by the vines. It is rich in limestone rubble, gravel, and catches and holds more fine earth fractions including transported clay that has flocculated there. Above ground scree litters the vineyards

The fact that most ownership parcels run in vertical rows, from the top of the vineyard, to the bottom, assures that any lighter, more finessed wines will contribute, but not dominate the overall blend. In other words, blending of heavier wines lower on the slope masks the lighter wines from the top of the slope. 

It is abundantly clear that the vines benefit from the higher levels of nutrients in these deeper soils. They develop grapes that carry more color (anthocyanins) and brings many times more dry extract to the wine. This translates as the wines of these vineyards having a richer, more velvety texture, increased depth, all of which covers the structure. On the opposite end of the spectrum, the upper-slope position of Ruchottes-Chambertin dictates that the soils there are very shallow, and while there is a high percentage of colluvium, it is not as rich in sand, silt or clay sized particles.  In fact, there are places the topsoil has completely eroded away, leaving fractured stone and primary clay and marly-limestone between the voids and breaks in the rock.

New research allows new understanding

Today we can examine this variation of limestone within a vineyard with a precision that was not possible a decade ago. This is due to the groundbreaking work of geologist Françoise VannierPetit and her mapping of the dominant limestone beddings of Gevrey. Through her work, we know that Ruchottes is a very homogeneous terroir, one with a very pure and hard limestone bedding dominating the vineyard. While the stone does not provide much in the way of nutrients to nurture the vines, we know it is well-fractured by two large faults that run through the vineyard.  Because of the vigorous faulting and fracturing throughout the vineyard, Ruchottes does produce a grand cru class wine, but it is a grand cru of a different character.

The geological factors in Ruchottes do not typically produce a wine with the substantial fruit or thickness of a Chambertin, and this ‘reduced’ level fruit often does not completely ‘blanket’ of structure in the wines from Ruchottes. This obvious structure is often mentioned in wine reviews, noting heightened acids and tannins, lending the wines a more angular construction than in other grand crus. By the same token, the wine from Ruchottes is often quite aromatic, with finer bones, for this wine, it means exhibiting more finesse, as well as giving the taster a heightened awareness of the wine’s precise rendering of detail. In another vineyard, this might be attributed to the grapes achieving less phenolic maturity, but the wines of Ruchottes are ripe, they just aren’t typically as large scaled or heavy. Moreover, they can be remarkably beautiful wines that can age effortlessly, for decades; often gaining poise, polish, and balance while doing so.

The gentle slopes of Chambertin. Photo: googlemaps

The gentle slopes of Chambertin. Photo: googlemaps

The substrata of Chambertin and Clos de Bèze is much more varied. With Vannier-Petit’s mapping information, we know that 35 million years ago the vineyards of Chambertin and Clos de Bèze were opened up by a large fault. This exposing the older (2 million years +/-) of softer bedding planes below.  They are both divided by four bedding planes, three of them being of soft, friable, impure materials, giving excellent nutrients.  This softer, highly fractured bedding allows the vines to thrive, and produce wines with much higher levels of fruit. This is the heart of Chambertin and Clos de Bèze.

Additionally, the twin vineyards are perfectly situated, mostly upon a gentle gradient which will resist erosion, or better yet, at the curb of the slope, where the soil is deeper,  The vineyards are well protected from wind, being squarely behind the hillside of Montagne de Combe Grisard. These two vineyards sit in the sweet spot of the heat trap formed by the hyperbolic concave of the slope. This positioning allows ripening occur even in most cold, wet years. Ruchottes, while fairly well protected, it is nearer the Combe de Lavaux through which cooling winds flow down the vast gorge.

All of these factors make the wines made from Chambertin and Clos de Bèze much easier wines to understand because they have so much to give. They can be very seductive and complex, and can be drunk either young or old.  Are they typically better wines than can be made in Ruchottes?  The knee-jerk reaction is yes, as Ruchottes can be equated to the man fighting with one hand tied behind his back. But when a well-made wine from Ruchottes is opened at the right time, and served with the right meal, it can be perfection.

Armand Roussaux parcel map

Chambertin clos de Beze

 

Digging deeper 

Gevrey-Chambertin topography

Generally speaking, when compared to vineyards in some of other villages, the grand vineyards of Gevrey are fairly mild in their gradient. The uppermost vineyard sites of the Chambertin-named vineyards butt up against the Montagne de Combe Grisard’s “chaumes”, (or ‘scruff ‘ in English). But unlike the steep upper hillsides of Vosne or Volnay that were able to be planted to vine, there is an unarable, rocky, forested landscape. Here in the chaumes, where no vines are planted, the hillside above Gevrey becomes steep.

The premier cru of Bel-Air is the one real exception. Carved out of a void in the rocky forest, and perched directly above Chambertin Clos de Bèze, Bel Air is a steep vineyard. It is a superb example of the struggles upper-slope vineyards face. See Part 3.3.1 for more on this. According to Vannier-Petit, a white Oolite formation underlies the uppermost section of Bel Air, and Premeaux Limestone underlies the lower part. Several writers have describe Clos de Bèze as having Oolite formations below the soils, but Vannier-Petit does not note this. Instead, it is likely that Oolite has slid, as scree, or even in large chunks as a rock slide, into Clos de Bèze, from Bel Air above.

A prominent feature of the area, as outlined by the late James E. Wilson, a geologist, and author of Terroir (1998), is a rocky outcropping he referred to as a “Comblanchien cap“. While this was not part of the vineyard landscape, he described it as a major feature of the “Nuits Strata Package.” This term,“Nuits Strata Package,” as coined by Wilson, is an overarching reference to the bands of limestone bedding that stretch from Marsannay to Nuits-St-George, a layering of limestones unique to the Côte de Nuits. An upper-band of Comblanchien stone, he wrote, formed a structural bulwark or ‘cap’ which has allowed the upper-hillside to resist erosion, while the softer center eroded more quickly. This has caused the Côte de Nuits to develop its hyperbolic concave slope-shape. This concave slope relief, as I wrote earlier, allows the heat of the sun is trapped, allowing fruit to ripen fully. This is particuularly true for vineyards such as this that sit in a wind shadow which is created by the trees and hillside above.

Interestingly, a much more recent map of Gevrey by Vannier-Petit, does not deem it necessary to include hillside construction above the vineyards.  So while she shows no Comblanchien cap rock at the edge of the Gevrey’s vineyards, as it seems Wilson described them, she does shows that the Premeaux stone extends one hundred or so meters up-slope. This extends well beyond the farthest, uppermost edges of the vineyard land.  While she may have felt the composition was outside the scope of the project, certainly anything that will wash, slide, or roll into a vineyard, is of great importance to our understanding of the physical vineyard makeup.

Ruchottes-Chambertin: a largely homogeneous appellation 

Here, a photo by Armand Rousseau illustrating the lack of topsoil, and the width of the fractures in the Premeaux limestone. No doubt this is a more extreme section, but it gives us the understanding of the relationship between the hard stone, fracturing and the difficulty of dealing with erosion in these vineyards.

Here, a photo from Armand Rousseau illustrates the lack of topsoil, and the width of the fractures in the Premeaux limestone. No doubt this is a more extreme section, but it gives us the understanding of the relationship between the hard stone, fracturing and the difficulty of dealing with erosion in these vineyards.

Ruchottes-Chambertin, and it’s ying-yang partner. Mazy-Chambertin (also spelled Mazis-Chambertin), sit at the tail end of the string of grand cru vineyards. The primary limestone beneath both vineyards is the significantly calcium-pure, Premeaux. Premeaux limestone, which is marketed as marble, is highly desirable for construction and prized for its pink color. It is very similar to Comblanchien (which is a creamy white), but slightly less pure, (hence the color), and slightly less resistant to geological strain. See Part 1.1 for detailed compressional strengths of various commercial limestones.

Technically, the Ruchottes appellation is made up of three small, roughly equally-sized vineyards:  Ruchottes Bas, (meaning the below) Ruchottes Hauts, (meaning above), and next to that, against the forested outcroppings at the top of the hill, Clos des Ruchottes. The Clos, is a monopole owned by the firm of Armand Rousseau.

While the lower half of the Clos des Ruchottes shares the rest of Ruchottes’ Premeaux limestone, the uppermost section, is covered in a layer of white Oolitic stone. Oolitic stone is made up of millions of small, oval, carbonate Oolite (egg stone) pellets that are fused by mineral cement. This composite construction makes the stone more susceptible to fracture, and the vines find it far easier to penetrate the many weak spots in this more porous stone. If anything, this is a benefit that the Clos des Ruchottes has over the rest of the Ruchottes appellation, especially since it is so high upon the hill. However we don’t know if the Oolite is of significant depth, and it is likely that Premeaux lies directly beneath it anyway. In either case, as vineyards go, the entire appellation of Ruchottes-Chambertin, is remarkably homogeneous in character.

The excellent Armand Rousseau website discusses Ruchottes Oolitic limestone, as well as shows the firm’s holdings in the vineyard, and is fairly detailed, and seemingly competent in their geological explanations, a surprising rarity in Burgundian marketing. Below is an excerpt.

The soil is composed of a shallow layer of red marl up to the top of the area. It is very pebbly, shallow and not fertile. The vines are based on oolithic limestone dating from Bathonien which disintegrates if frozen producing scree. This soil type forces the roots to go deeper into the rock. This results in a more fragrant, mineral style of wine that is lighter in colour but with a fine and elegant body. domaine-rousseau.com/en

Examining Ruchottes faulting and fracturing

We know through of the study of fracturing along the Arugot fault in the Dead Sea Basin, that as the distance from the fault increases, fracturing diminishes in frequency. This means that fracturing still occurs in its clusters, but the spacing between clusters is farther apart, leaving stretches of relatively undisturbed stone between areas of fracturing. As Ruchottes is located at the farthest possible distance in Gevrey from the main Saône fault, we rightly might expect this hard stone to be only intermittently fractured. Certainly there have been numerous accounts over the past century of vignerons having to dynamite sections of these vineyards to break up the stone enough to plant their vines.

Mazy and Ruchottes Chambertin with dip and strike oriented faults. Significant outcropping has emerged from this hard Premeaux stone at the convergence of these faults. Interestingly its both parallel and perpendicular to the extensional, horizontal faulting

Mazy and Ruchottes Chambertin with dip and strike oriented faults. Significant outcropping has emerged from this hard Premeaux stone at the convergence of these faults. Interestingly its both parallel and perpendicular to the extensional, horizontal faulting

Unknown before Vannier-Petit’s work were the locations of sub-faulting that occurred at the same time that the Saône Fault developed.(1) Two sub-faults bi-sect Ruchottes and Mazy, right at the border with Clos de Bèze. The vertical fault-line follows the boundary between the Premeaux stone and the various beddings that make up Clos de Bèze.

Ruchottes origin during of the Côte’s creation 

The once level Premeaux limestone bedding of Ruchottes came under great strain as the land that now forms the Saône Valley Basin pulled away and began its slide down. As the limestone slab was pulled extensionally, the once solid piece of limestone bedding first began to microfracture, then to fracture throughout the body of the stone. As understood by the study of fluid mechanics, stress intensifies exponentially upon weakest areas of the stone, from which fracturing propagates, until the main horizontal break, or fault occurs.

As this faulting occurred, the neighboring blocks of limestone were pulled downward by the void made by the dropping/falling off the fledgling Saône Valley. As this happened, bedding of Ruchottes began to tilt and slide downwards, both pulled and sliding with the adjacent formations. It is not clear if this was a rapid, cataclysmic event, or that it happened over the span of hundreds of thousands, or even millions of years. Either way, the stress upon the Premeaux bedding of Ruchottes was extraordinary, and what fracturing that was not caused the faulting, certainly occurred as it tilted and moved its position downward.

Often times, faulting can cause one plate to sit significantly higher than the next, forming a drop off which may or may not fill with soil.  In some locations, such as the fault between Chevalier-Montrachet and Le Montrachet, this has occurred What soil was lost by Chevalier to erosion, found a fine resting place in Le Montrachet, allowing the soils of Le Montrachet to become much deeper (and richer).  In other instances, erosion may once again level any difference in bedding height created by faulting. Alternately, the bedding may remain at the same height following the fault creation.  To the best of my knowledge, any height differential between Ruchottes du bas and Mazy Hauts is not documented.

Looking at the satellite image, there are certainly several visual clues that this faulting exists. Most obvious are the signs of significant stress are the limestone ridges, where the bedding has folded upon itself, that pushed above the topsoil. These are dominate features directly above the southern end of Mazy Haut, and just like the walls of Clos, these limestone ridges greatly reduce erosion in these areas, which results in deeper richer soils and thus weightier wines, not only in Mazy, but in that area of Ruchottes du Dessus.

Clos de Beze & Chambertin: four distinct bedding planes

Here the soft friable makeup explains the ease that the vines have in extracting nutrients and water from the base rock

Here the soft friable makeup explains the ease that the vines have in extracting nutrients and water from the base rock

While Chambertin and Chambertin Clos de Bèze are very similar to each other, they are unique to all other vineyards in Gevrey. Both vineyards share the same four bands of bedding planes, in roughly the same proportions. The one largest difference between them is that there is a higher percentage of Crinoidal stone in Clos de Bèze than exists in the northern end of Chambertin.  However, what is farmed depends completely on the parcels owned, not what exists in the vineyard itself.  It is increasingly clear is that a parcel is a vineyard in itself, and sections within parcels can hold wide variation in the character of wine it will produce.

Upper-slope Bathonian beddings:

Premeaux limestone and Argillaceous limestone/Shaley limestone

The uppermost sections of both Clos de Bèze and Chambertin sit over the very pure, and hard, Premeaux limestone, formed during the Bathonian which is a 2 million year period of the upper middle Jurassic. As in Ruchottes, we can expect this Premeaux limestone to be fairly well-fragmented. If this were the only stone found below the surface of these vineyards, the wines would taste much more like Ruchottes, but that is not the case.

The middle-upper section of these sibling vineyards is argillaceous limestone. This is a calcium-rich clay matrix may be indurated into stone, or it also may be soft and more marly. The clay, or argile as it is called in French, normally composes up to 50% the matrix, with roughly the balance being calcium carbonate and impurities. To this Vannier-Petit adds the word hydraulique, (in parenthesis), which refers to the fact that this particular limestone contains silica and alumina, that will yield a lime that will harden under water.  The assumption is that this Calcaire Argilleux formed underwater in the Jurassic lagoon or seashore, by secreting quicklime which bound with the clay, 168 million years ago.

Decanter Magazine alternately, and perhaps inaccurately, translates from the French Calcaire Argilleux, into Shaley Limestone, (as seen in the map box). That said, Françoise VannierPetit describes in an interview, that the relationship of clay and shale, is almost as one material that continually is in a transition from clay to shale – and back again, depending on how hardened (indurated) it becomes, or degraded. That stated, shale is generally regarded as lithified clay mixed with silt, the blend of which causes the notable horizontal striations, while a body of transported clay (of a single type, ie. Kaolin) that has been indurated (hardened) is termed claystone. Geologist are notorious for their loose use of terms, which makes it challenging for the rest of us to catch up, and I suspect Vannier-Petit is often guilty of this. AC Shelly is credited with writing in 1988 that “The term shale, however, could perhaps be usefully abandoned by geologists, except when communicating to engineers or management‟

Nothing is as simple as a name. Shale can be found in many forms. The relationship between clay and shale is very tight, just like water and ice.

Nothing is as simple as a name. Shale can be found in many forms. The relationship between clay and shale is very tight, just like water and ice.

Middle to lower slope Bajonien beddings: 

Marnes à Ostrea acuminata & Crinoidal Limestone

The oyster, and other fossils that sedimentologists are constantly mentioning as being present the bedding is really only relevant because it allows the scientist to easily reference age of the material. The fact certain creatures lived only during distinct periods of time, and only in certain environments. So not only does it give scientists the age of the strata, but it tells them a lot about the particular conditions that existed in that location, quickly allows the scientist to assign the formation of the bedding material to a particular period of time. As the fossils display different signs of evolution, (in the case some oysters, their valve position changed over long periods of time) the sedimentologist can establish the age bedding, and allow them to recognize a change of bedding (at on the surface) simply by the fossils in each location.

Using this methodology, the scientist gleans information about how the bedding has shifted position, or even its location. These shifts have been very significant in the Côte. By categorizing strata by type, and fossil type. and date, they can match one strata in one location with its mate in another.  This methodology allows sedimentologists to correlate strata worldwide.

Oyster bedIn the vineyard of Chambertin, the marl (Marnes à Ostrea acuminata) lies in a layer just beneath the argillaceous material that once was an ancient oyster bed. It is loaded with fossilized oyster shells (Ostrea)  from the upperBajocien period. This soil, into which the fossils are bedded, contains a large amount of the clay, montmorillonite, which has a very high cation exchange rate, and such soils, with their negative charge, attract and hold positively charged ions called cations (minerals like calcium (Ca++), magnesium (Mg++), potassium (K+), ammonium (NH4+), hydrogen (H+) and sodium (Na+) that are crucial for plant growth. This makes this particular marl which lies in the heart of Chambertin, a particularly sweet spot for vines. And because this is a bedding plane that underlies the Argillaceous material above it, those vines whose roots can reach that deeply, may benefit from the Marnes à Ostrea acuminata too. That said, the deeper roots, it is reported, do not typically supply vines significantly with nutrients, that vines rely on their shallower root systems for this function.

gevrey pre slideThe age of the Marnes à Ostrea acuminata dates back to the very late Bajocian, parkinsoni zone 168.3 +/-, well before the Premeaux which lies above it was formed on top of it. This important because this decisively shows that the Comblanchien bedding, which lies at the base of the hillside (and was formed later in the Bathonian), slid down slope, and was pulled eastward with the falling valley. This slide of the Comblanchien, which at one time overlaid the argillaceous and oyster marl material and lay next to the Premeaux, moved downward almost 100 meters and eastward by roughly 200 meters. exposing this older marl and crinoidal bedding to the air, after having been buried underground for the previous 133 million years. The next bedding plane is the also Bajocien in origin, again being older than the Premeaux higher on the hill, and older than the Comblanchien which sits below both Chambertin and Clos de Beze.

The lowest section of Chambertin, and the largest percentage of Clos de Beze’s acreage consists of the well-fractured Crinoidal Limestone. This is the most common base rock upon which, the classified crus of Gevrey are planted.

Crinoids were extremely prevalent the lagoons and Jurassic seas worldwide, until the Permo-Triassic extinction when they were virtually wiped off of the geologic record. Their fossilized remains create weakness in the stone that encases them. This weakness in the stone, coupled with the geological fracturing of the area, has made it relatively easy for the vine’s roots to penetrate deep into this rock strata. Impurities in the stone’s construction, allows for chemical weathering, brought about by rainwater infiltration, to create rich primary clay bedding for the vines, within the breaks and gaps in the rock. These factors have proved that Crinoidal limestone provides a very effective and fertile bedding for Pinot Noir to grow.

Wilson described the Crinoidal limestone as being “cracked by numerous small faults which ‘shuffle the cards’ of strata, but generally are not large enough to ‘cut the deck’ to introduce markedly new strata.” Terroir (1998) p.131.  This is typical of his breezy style, and while it is visual (in terms of cards), it really doesn’t have much concrete meaning, other than being a colorful way to say the crinoidal stone is well-fractured. He does go on to say that this extensive fracturing allows the stone to be a good aquifer for the vines.

crinoids

Colluvium: atop the bedding planes

Almost every grand cru vineyard in the Côte de Nuits has significant amounts of colluvium mixed in their soils. While Ruchottes-Chambertin does have colluvium is one of the most glaring exceptions it is not significant in quantity.  Typically, this colluvium is accompanied by a fair amount of transported clay, which when together often forms marl.(2)  Rarely does one exist without the other in vineyards that have been classified as grand cru.

In the Côte de Nuits, there tends to be more colluvium in the colluvium to clay matrix, while in the Côte de Beaune, there tends to be more clay.  This tends to the case because there are many more marl bedding planes in the Côte de Beaune than there are in the Côte de Nuits, where marl bedding is rarer. There may be more shale in the Côte de Beaune as well.

 

The tête de cru, –  the very finest of the grand cru vineyards, have relatively equal proportions of marl and colluvium and sit only upon the slightest of slopes. This applies to the vast majority of Chambertin and Clos de Bèze vineyard area. These crus possess a perfect planting bed for vines: they have colluvium/marl based topsoil that is at least 50 cm (19 inches) deep where the absorbing roots are active.(3)  Because of this construction, the soil has good porosity for root and water infiltration but is not so porous a material that the water does not drain right through it, or cause it evaporates quickly from it. Additionally, because of its rocky nature, the grand cru soils tend to resists compaction.

While there is a band of harder, less fertile Premeaux stone on the uppermost slopes of Chambertin and Clos de Bèze, this represents a minority proportion of these vineyards. Parcels that have vines on these upper slopes, often lend a measure of finesse to the finished wine, without impacting the palate impression of the finished blend. For these reasons, Chambertin and Chambertin Clos de Bèze are among the finest vineyards in the Côte de Nuits.

Clos des Ruchottes, (and Ruchottes in general) is a far different vineyard than its two neighbors. With the near-pure calcium stone beneath its shallow soils, the low levels of impurities mean that when it weathers,  very little clay is produced. Because of the scant soil, the vineyard their neither contains nor can it attract, as much in the way of nutrients for the vines as can Clos de Bèze with which it shares a border. The resulting wines typically have less fruit, less color, seem more structured or tannic, and have a finer, though thinner texture. On the upside, the vineyard produces a very classy wine that can have excellent aromatics, remarkable finesse, and has excellent age ability.

Agree? Disagree? Comments are welcome and encouraged! Please feel free to like or share this, or any other article in this series!


Note: Many authors note that Clos de Bèze has Oolitic limestone. Vannier-Petit does not note this on her map. Instead, she places the Oolitic stone in the premier cru of Bel Air, which sits directly above it. A likely explanation of Oolite being cited as existing in Chambertin is scree/colluvium from Bel Air has slid down, to litter Clos de Bèze from above.

(1) The problem with always talking about the Saône Fault, is it ignores the fact that the fault is really the most minor part of the geological event that happened. It was a continent being pulled apart, that caused a void into which the land adjacent to the Cote d’Or fell into a trough which would become the Saône Valley. The Saône Fault is nothing more than as scar marking that event. And in fact, the Saône Fault lies buried quite deeply underground – its general location is only estimated.

(2) Marl would require a smaller particle size than just rock and gravel sized limestone pieces to produce the non-clayey consistency that marl displays.

(3) Despite the conventional wisdom to the contrary, it is this shallow absorbing root system that gathers the majority of nutrients that vines require.

 

Understanding the Terroir of Burgundy: Part 3.3 The Upper Slopes

Shallow topsoil over hard limestone: a site of struggle

As I touched on in the introduction of slope position in Part 3.2, there are significant variables effecting which vineyards can produce weightier wines further up the slope. However, as a general rule, the steep upper-slopes are far less capable of producing dense, weighty and fruit filled Burgundies that are routinely produced on the mid and lower slopes.

The lack of water, nutrients and root space

The scree filled Les Narvaux in Meursault. photo: googlemaps

The scree filled Les Narvaux in Meursault. photo: googlemaps

In many of these upper vineyards, the crushed, sandy, and in some places powdery, or typically firmer and more compact, the marly limestone topsoil overlies a very pure limestone, such as Comblanchien, Premeaux and Pierre de Chassagne. Here, the extent of that the stone is fractured determines the vines ability to put down a healthy volume of roots to support both growth and fruit bearing activity. Any gardener can tell you that insufficient root space, whether grown above a shallow hardpan or in a pot, will cause a plant to be root bound and less healthy.

Because these steeper vineyards can neither develop, nor hold much topsoil to its slopes. The topsoil, which can be measured in inches rather than feet, tends to be very homogeneous in its makeup; a single horizon of compact, marly limestone, with a scant clay content of roughly 10-15%. The infiltration of rainwater and the drainage are one and the same. Retention of the water is performed almost solely by this clay content, and evaporation in this confined root zone can be a significant hazard to the vine. Fortunately rain in Burgundy during the growing season is common, although rainfall from April to October, and particularly in July, the loss of water in the soil is swifter than it’s replacement from the sky (Wilson, “Terroir” p120).

Infiltration Rates of Calcareous Soils

A study by A. Ruellan, of the Ecole National Supérieure Agronomique, examined the calcareous (limestone) soils of Mediterranean and desert regions, where available water and farming can be at critical odds.  He studied two major limestone soil types. The first was a light to medium textured, loamy, calcareous soil (60 – 80% CaCO3), and the second was a powdery and dry limestone soil with no cohesion. This second soil had a calcium carbonate content that exceeded 70%, and had 5% organic matter and a low clay content. The water holding capacity of this soil was a mere 14%. The depth of this soil was over 2 meters deep, which likely does not allow weathered clay accumulate near the surface, as it does in Burgundy.

Both limestone soils had very high permeability, with an infiltrate at a rate at a lightning fast 10 to 20 meters per day (or between 416 mm per hour and 832 mm per hour).  Even if rainwater infiltrated at half that rate through Burgundy’s compact limestone soils, it would virtually disappear from the topsoil. This is the area where the majority of the vines root system exists, and part of the root system responsible for nutrient uptake is within this topsoil region.  In this case of these soils, the vines must send down roots to gain water in the aquifer. Wittendal, who I wrote of in Part 3, suggests in that the vines literally wrap their roots around the stone, and suck the water from them.  I have seen little evidence that limestone actually absorbs water due to many limestone’s high calcium content and lack of porosity. This would be particularly true on the upper slopes under consideration now. It would be up to the roots to attempt to penetrate the stone in search of the needed water.

The root zone

Root development through soil

This slide represents the root development in shallow topsoil over a lightly fractured limestone base vs a deeper soil situation with four or five separate bedding horizons, such as exists lower on the slopes of burgundy.The effect infiltration rates have depends significantly on the distribution of vine roots. In most planting situations, 60 percent of vine roots are within the first two feet of topsoil, and have been known to attain a horizontal spread of 30 feet, although the majority of the root mass remains near the trunk.

By design, vines rely on the roots established within the surface soil – which is where nutrients (ie nitrogen, phosphorus, potassium) are found – to gain the majority of their sustenance. They send down deeper roots to gain water when it is not available nearer the surface. However in Burgundy, many of the steeper slopes present planting situations where not only is the soil very shallow, but the nutrients are poor. The limestone in these vineyards often is hard and clear of impurities, and within the same vineyard may vary significantly in how fractured the stone is. Because of this, in some locations vines have difficulty establishing vigorous root penetration of the limestone base, and this can dramatically limit the vine’s root zone.

Additionally, because of the soil’s shallow depth, , and because of the soils high porosity and low levels of clay and other fine earth fractions, only a limited volume of water can be retained

Water is critical for both clay’s formation and its chemical structure, and the clay will not give up the last of what it needs for it own composition. The evaporation rate of what little water there might remain, can be critically swift.

Rainwater’s infiltration of the limestone base, and its retention of water can also be limited where significant fracturing has not occurred. Any water that cannot easily infiltrate either the soil or the limestone base, will start downward movement across the topsoil as runoff. That means any vine that has been established in shallow topsoil, or the topsoil has suffered significant losses due to erosion, will be forced to send roots down to attempt to supply water and nutrients.

Vine roots and a restricted root zone

In non-cultivated, non-clonal vines, powerful tap roots are sent down for the purpose of retrieving water when it is not available in from the surface soils. However our clonal varieties are more “highly divided” according to the “Biology of the Grapevine” by Michael G. Mullins, Alain Bouquet, Larry E. Williams, Cambridge University Press, 1992. The largest, thickest, roots develop fully in their number of separate roots, by the vine’s third year, and are called the main framework roots. Old established vines in good health may have main framework roots as thick as 100cm (40 inches) thick. This main framework root system, in normal soils, typically sinks between 30 cm (11 inches) and 35 cm (13 inches) below the surface.  In shallow soils, they may hit hard limestone before full growth, and may have to turn away, or stop growing. Anne-Marie Morey, of Domaine Pierre Morey, echoes this in talking with Master of Wine, Benjamin Lewin, of their plot in Meursault Tessons. “This is a mineral terroir: the rock is about 30 cms down and the roots tend to run along the surface.”

From the main framework, grows the permanent root system. These roots are much smaller, between 2 and 6 cm, and may either grow horizontally (called spreaders) or they may grow downward (known as sinkers).  From these permanent roots grow the fibrous or absorbing roots. These absorbing roots are continually growing and dividing, and unlike the permanent roots, are short-lived. When older sections absorbing roots die, new lateral absorbing roots to replace them.

This cutaway of the topsoil of Gevrey Bel Air shows just how limited the root zone is in this premier cru vineyard. The Comblanchien below is being 'reconditioned' in this plot. More on this in a near future article. click to enlarge.

This cutaway of the topsoil of Gevrey Bel Air shows just how limited the root zone is in this premier cru vineyard. The limestone below is being ‘reconditioned’ in this plot. click to enlarge.

Although the permanent sinker roots may dive down significant depths, the absorbing roots (which account for major portion of a vine’s root system account for the highest percentage of root mass, typically only inhabit the first 20cm to 50cm, or between 8 inch and 19 inches of a soils depth (Champagnol,  Elements de Physiologie de la Vigne et de Viticulture Générale 1984). Clearly this is an issue if the topsoil is only 30 cm (12 inches) to begin with.  If the absorbing roots are not growing sufficiently on the sinkers, the vine must rely on the exceptionally poor topsoil of the marly limestone.

South African soil scientist Dr. Philip Myburgh found (1996) that restricted root growth correlated with diminished yields. He also found that the “critical limit’ of penetration by vine root was 2 MPa through a “growing medium”. Weakness in the bedrock, and the spacing of these weaknesses, contributed to a vines viability.

The vines on these slopes, on which there is limited fracturing of the harder, non-friable limestone, have difficulty surviving. These locations often shorten the lifespan of the vines planted there, compared to other, more fertile locations in Burgundy, where vines can grow in excess of 100 years. It is these vines, with barely sufficient nutrients that make wines that don’t have the fruit weight that I wrote of before, simply because they cannot gain the water and nutrients necessary to develop those characteristics. The amount of struggle the vine endures directly determines the wine’s weight, or lack of it.

It is ironic, that when we research the issues the catchphrases of wine describe, ie, the “vines must struggle”, or that a vineyard is “well-drained”, or the vineyards are “too wet to produce quality wine”, we see the simplicities, inaccuracies, or the shortcuts that those words cover up. Yet these catchphrases are so ingrained in wine writing, that we don’t even know to question them, or realize that they require significantly more nuance, or at minimum, point of reference. Yes, the vines on the upper-slopes are particularly well-drained. They do indeed struggle, sometimes to the point of producing vines are not healthy, and cannot the quality or the weight of wine that the producer (dictated by their customers) feels worthy of the price.

Extreme vineyard management

Blagny sous la dos d'Ane's shallow red soils produce a Pinot that is too light for the market to bear at the price it must be sold. photo: googlemaps

Blagny sous la dos d’Ane’s shallow red soils produce a Pinot that is too light for the market to accept – at the price it must be sold. photo: googlemaps

In Blagny, the Sous le dos d’Ane vineyard, which lies directly above the small cru of  Aux Perrières, has seen at least one frustrated producer graft their vines from Pinot Noir to Chardonnay. The Pinot, from the red, shallow, marly limestone soils, was felt to be unsatisfactorily light in weight. Not only would a lighter-styled, and minerally Chardonnay be well received, the producer will be able to sell it much more easily – and for more money because he could then label it as MeursaultSous le dos d’Ane, a much more marketable name.

Bel Air. More photos on this excellent website, and a terrific discussion in the comment section, albeit in French. Worth running through a translator. source: http://www.verre2terre.fr/

Bel Air. More photos on this excellent website, and a terrific discussion in the comment section. source: http://www.verre2terre.fr/

Producers in the Côte de Nuits rarely have the option to switch varietals. They typically must produce Pinot Noir to label as their recognized appellation. In the premier cru of Gevrey-Chambertin “Bel Air”, and Nuits St-Georges “Aux Torey”, growers have gone to the extreme lengths and expense of ‘reconditioning’ their plots. To do this, they must rip out their vines, strip back the topsoil and breaking up the limestone below. In the adjacent photo, a field of broken Premeaux limestone and White Oolite has been tenderized, if you will. The soil is replaced and the vineyard replanted. The entire process requires a decade before useful grapes can be harvested once again from the site, costing an untold number of Euros spent, not to mention the money not realize had the old vines been allowed to limp on. The same has been done in Puligny Folatières in 2007 by Vincent Girardin, and there again in 2011 by another unknown producer. Ditto with Clos de Vergers, a 1er cru in Pommard in 2009.

 

http://www.wineterroirs.com/2009/11/landscaping.html

click here: for the previous article, Understanding the Terroir of Burgundy: Part 3.2 The lower slopes

Understanding the Terroir of Burgundy, Part 2.2: Soil formation

We all know what soil is, or at least we think we do. If I were to ask you what was in soil, what would you say?

by Dean Alexander

In healthy soils, minerals typically only represent slightly less than half of the volume of soil, while air and water incredibly represent much of the rest. Here is the soil of La Tache in Vosne Romanee.  photo: leonfemfert.wordpress.com

Soil: 45, 25, and 25%

Despite all the talk about limestone, to really understand the terroir of Burgundy, we really have to understand what soil is and the material from which it is eroded. The mineral component, or the part we think routinely of as soil, are typically only 45% of the soil matrix. The balance is actually 25% air, and a further 25% of water, with the last 5% being split between humus (4%), roots (.05% ), and organisms (.05). It would make sense that this percentage changes seasonally, depending on how much water is in the soil from rainfall (or the lack of it) which changes the ratio of minerals, water, and air. Further, these ratios can change based on soil compaction, which decreases the air in the soil, which in turn increases the percentage of the mineral and organic component.  Why is this important? Because this is the environment that the vines live and they require a certain ratio of each of these components to produce high-quality grapes.

Cote soil influencers

I developed this graphic to illustrate the assorted soil formation processes that affect the Côte, and are described in depth in Limestone Fracturing in Part 1.2, and from Limestone to Clay in part 2.1, in earlier articles in this series. This article, Part 2.2 Soil Formation, builds upon those earlier concepts.

 The 45%: Burgundy’s mineral makeup

The French refer to the loamy Saône Valley fill as Marne des Bresse. The earth there is very deep, and typically is too wet for high-quality grape production. Historically this been used for pasture land for sheep and cattle. With every storm, this rich loam from the valley intermixes a little bit more with the soils of the boundary vineyards, and even encroaches on the loose, stony soils of the Côtes lower slopes.  ‘Interfingering’, was how geologist James E. Wilson described this mixing of soils in his 1990 book, Terroir: The Role of Geology, Climate, and Culture in the Making of French Wines.

Bore samples, according to Wilson, had indicated that this interfingering has reached westward, up the hill, to influence the soil construction of the lower sections of the grand cru Batard-Montrachet. With this information, he inferred that the Saône fault must be near.  It is notable that in 1990 precise location Saône fault was not known, and around Puligny, it still may not be. I suppose the wealthy Puligny vintners have no need to explain why Puligny-Montrachet is great. Vannier-Petit however, does tacitly show the Saône fault in her map of Gevrey, which is represented by the abrupt end of the limestone bedding east of RN74.

The ravine Combe de Lavaux defines character of most of the premier crus of Gevrey-Chambertin, but more importantly, its alluvial wash greatly expanded the growing area of vineyards below the village. Click to enlarge

The ravine Combe de Lavaux defines the character of most of the premier crus of Gevrey-Chambertin, but more importantly, its alluvial wash greatly expanded the growing area of vineyards below the village. Click to enlarge

Because the Côte is an exposure of previously buried, older limestone, younger soils line the divide on either side of the escarpment. The Saône Valley’s Marnes de Bresse brackets the Côte on the eastern, lower side of the slope, while younger rock and soil material that cover the tops of the hills, to the west, and beyond.

From the hilltops above, those younger soils have eroded down, bringing feldspar and quartz sand, silt, as well as phyllosilicate clay minerals, to help fill in and strengthen the rocky limestone soils of the Côte. In many places, geological faulting, coupled with runoff or streams, have created combes or ravines which have allowed substantial alluvial washes to extend the planting area of the Côte. A prime example of this is the Combe de Lavaux which is a dominate feature of the appellation of Gevrey-Chambertin.  It has sent a large amount of alluvial material around and below the village of Gevrey, creating good planting beds for village-level vineyards. Alluvial soils are nothing more than a loose assortment of uncemented of soil materials that have been transported by rain or river water. These materials are typically sand, silt, and clay, and depending on the water flow, various sizes of gravel particles. It is this sand and gravel that has traveled with the water flow from the Combe, that provides these vineyards that protrude past the limestone of the escarpment the drainage the vines require.  These are not, however, the soils that will produce the great premier cru, or grand cru, wines for which Burgundy is famed.

a graded sediment bedSoil suspension and graded bedding

Soil moves downslope by water erosion, the force of gravity, and even is transported by the force of significant wind. With movement, the particles within the topsoil are in a state of suspension. Geologists refer to this movement and suspension as turbidity. Because of their weight, gravel travels downward in the moving soil, creating a progressively sorted soil, with coarser pieces on the bottom, while the finer particles find their way to the top.  The result of this is called a graded sediment bed. (1)

While it is easier to see how a graded bed might be created in a stream bed below a ravine like the Combe de Lavaux, I was somewhat perplexed how this might occur in Alex Gamble’s Les Grands Champs vineyard in Puligny-Montrachet, see Clay part 2.1.  Here gravel bedding lay at 80cm, a little more than two and a half feet below the surface. Above the gravel, sat a foot and a half of heavy, yellow, clay-dominated soil. This was, in turn, topped by nearly a foot of loamy-clay soils. Vannier-Petit estimated these soil horizons, as geologists refer to them, were created between two and five million years ago by water runoff. What kind of run off?  I realized that the kind of runoff that creates graded bedding happens often, like in this photo (below), taken in Pommard during the winter/spring of 2014, by winemaker Caroline Gros Parent.

This is how graded bedding develops.

This is how graded bedding develops. Here the road to Pommard has flooded in the winter storms of 2014. Photo: Caroline Parent via twitter

Parent material

Geologists talk about a soil’s parent material because every element of soil came from a different material, which was then weathered, both mechanically and chemically, into various sizes. These minerals will then accumulate, either poorly sorted into an aggregate material, or they can be well sorted by the wind, water, or gravity into size categories. Sand and silt are generally said to have been created by mechanical weathering, although chemical weathering is always a present force, as long as there will be rain. Sand can be made of any parent rock material, but in Burgundy, there are sands made of granite, in addition to plentiful limestone sand. (2) We know this because there is loam present (as well as graded bedding), in the Grands Champs vineyard from the Saône valley fill below. The water that carried this non-limestone, Côte-foreign material, would have carried quartz sand with it as well when it created the graded bedding there. This gives us a very important insight into the construction of the soils of Burgundy.

Fine earth fractions

Fine Earth Fractions are the trinity of sand, silt, and clay. Gravel and sand can be made of limestone or other rock that has been weathered into smaller and smaller pieces, but silt is typically feldspar or quartz. Clay is much, much smaller in size, and is created by chemical weathering of rock. Its parental material can be limestone, granite or other stone.

Geologists grade soil minerals by size; the basis of which are particles that are 2 mm and smaller. These are called fine earth fractions and consist of sand, silt, and clay. In equal thirds of each of the three soil fractions is considered perfect for farming crops, and is termed loam. The various sizes of minerals in the soil makeup gives the soil its texture.

Clay, we have talked about in length in part 2.1, and differs from silt and sand because it is a construction from stone that has been chemically weathered, whereas silt and sand are derived from mechanically weathered rock. Additionally, clay is a construction of clay minerals that are bound with aluminum and oxygen by water and carries minerals within its phyllosilicate sheets. It is also important to mention that clay’s particles are considerably smaller in diameter, being less than 2 microns in size.  Soils with more clay hold more water,  so they require less frequent application. An overabundance of water in clay soils causes oxygen depletion in the root zone.  This can limit root development.  The abundant solvent calcium in the limestone soils Burgundy misaligned the clay platelets, loosening the soil, and allowing better drainage.

Diatoms (top) and Radiolarians bottom, fill the ocean floors with sediment.

Diatoms (top) and bottom, fill the ocean floors with sediment.

Silt is specifically formed from quartz and feldspar, and is larger than clay, being 0.05 mm-0.002 mm. We know that any feldspar in the soil, could not have come from weathered stone; neither limestone or granite, which was the dominant stone in the area when the limestone beds were forming, because it would have metamorphosed into a phyllosilicate clay mineral if it had. This means the feldspar has traveled onto the Côte, either from above or below the limestone strata.

While it might seem logical to assume the quartz in silt originated in the earth’s crust, and perhaps degraded from granite that was prevalent in the area, this may not be the case. The first problem is quartz is resistant to chemical weathering. And physical weathering like frost wedging of sand particles may continue to yield results beyond a certain size.

Researchers from the University of Texas at Arlington used (and I cut and pasted this) a “backscattered electron and cathodoluminescence imaging and measure oxygen isotopes with an ion probe.” They found that the 100% of silt quartz found in 370 million-year-old shales of Kentucky were made from the “opaline skeletons” of plankton, radiolarians,  and diatoms. This, they reasoned, might explain the lack of these kinds of fossils during the same period. These tiny animals had all been incorporated into the then forming shale. This may also be the case for the silt quartz of Burgundy, itself too having once been a Jurassic, seaside resort. This, in fact, this information also suggests this quartz silt may come from weathered shale that is much older than the limestone of the Côte.

A sandy soil horizon

A sandy soil horizon

Sand is larger than silt. being less than 2 mm, and typically is constructed of quartz or limestone particles. The limestone sand will weather to solvent calcium carbonate, but the quartz will not weather and will remain as sand. It is likely that significant quartz sand has been washed down from the hillsides, and certainly is a major contributor to alluvial soils below the combes. Sand drains so quickly that vines grown in sandy soil have more frequent water requirements, but require a lesser amount of water.  Adequate water maintains plant growth while minimizing the loss in the root zone.

 Plant and animal soil contributors

Grasses, with their dense root systems, are positively impactful to the topsoil. In their decomposition, darker soils are created to deeper depths, and the resulting soils also tend to be more stable.  In a monoculture of grapevines, many growers are finding this to be a significant advantage. In Australia, some grape growers are using grasses to help lower soil temperature in efforts to slow down ripening in an ever-warming climate.

Much is made by those practicing sustainable and organic cover crop encourage populations beneficial predator insects and birds, but grasses and cover crops also encourage subsoil organisms and microorganisms growth as well. Most common are bacteria and actinomycetes (rod-shaped microorganisms), which by weight have been found to be four times more present by weight than earthworms in healthy soils. While these are important to the quality of the wine, they are only an intricate part of terroir if it is practiced by the farmer.

The 25%: Air (and soil compaction)

Soil compaction relates to poor water infiltration and low oxygen levels. drawing: landscaperesource.com

Soil compaction relates to poor water infiltration and low oxygen levels. drawing: landscaperesource.com

The proper amount of airspace between mineral fragments is very important for vine growth and allow for water to penetrate and be retained by the soil. Soils with diminished airspace are said to have soil compaction, and compaction is difficult to correct once it has occurred. The Overly tight spacing between the mineral component of a soil restricts oxygen levels and contributes to a poor water holding capability.  Rainfall itself can cause some soil compaction, but most commonly walking or operating farming equipment on moist soils does the most damage. In drought years, soil compaction can lead to stunted vine growth and decreased root development. In wet years, soil compaction decreases aeration of the soil and can cause both a nitrogen and potassium deficiency. Additionally, without adequate porosity to the soil, water cannot easily penetrate the soil during a rainstorm. Water that cannot infiltrate soils of flat terrain can stagnate, which further compacts the soil,  or on sloped terrain will runoff, which can create erosion problems.

Positive effects of moderate compaction

As moisture of the soil increases, so does the depth of compaction.

As moisture of the soil increases, so does the depth of compaction.

Moderate compaction can have some desirable effects. Moderate compaction forces the plant to increase root branching and encourages secondary root formation. This additional root growth is the plant’s response to not finding enough nutrients with its existing root system. Plants with more extensive root systems are more likely to find nutrients that are not carried by water, like phosphorus.  Obviously, more compaction is not better, because it impedes root growth, lessens the oxygen in the soil, and repels water from penetrating the soil.

While deep tillage 10-16 inches can shatter the hard packed soil, studies have shown that crop yields will not return to normal following the effort. While there are factors that might cause the soil to return to compaction, like a farmer, unintentionally re-compacting their soils, more than likely tilling does not return the airspace that was lost in the soil itself. Further continuous plowing and tilling at the same depth can cause serious compaction problems on the soil below the tilling depth.

The 25%: Water (the key to everything that Burgundy is)

It should be impossible to talk about soil without talking about water, given it is optimally 25% of soil’s makeup. It is certainly tempting to pass over the subject of groundwater and lump it into erosion, but that would really shortchange our understanding of the Cote. Part of Burgundy’s success can surely be attributed to relatively steady rainfall year round, coupled with the fractured limestone’s ability to hold water until its reserves of water which is held within the stone can be recharged by future storms.

Good drainage, well-drained? Let’s reset the dialogue.

The infiltration of rainfall by the soil is the first and perhaps most important factor in recharging groundwater levels. Like I wrote of compaction, the soil has to be porous enough to penetrate the topsoil and subsoils successfully. The buzz word in the wine world is drainage, with terms like well-drained, and good drainage appearing often. I suppose we picture the roots drowning in mud if there isn’t good drainage. But the idea of good drainage really simplifies the issue. Drainage can have to do as much to do with compaction as soil materials or slope. Soil drainage is important in fighting erosion as well not causing additional soil compaction. Good drainage, which is what happens with a well-aerated soil, allows the vines roots sufficient oxygen and nitrogen and allows the roots to take in nutrients like phosphorous and potassium. But none of this can happen if the soil releases rainwater too quickly, and the vine can perform none of these vital tasks. The reality is, it is not the fact that a soil well-drained, but rather it drains at the adequate rate for a given rainfall. Obviously, this will not always be a perfect equation since rainfall varies greatly depending on the year and the time of year.

The speed of drainage

water movement through various soil types. source: usda-nrcs

Water movement through various soil types. source: USDA-nrcs

The kinds of materials that make up the soils contribute greatly to the rate of water ability percolate through the material. The speed of the mater’s movement depends on the path the water is channeled in. The most direct path that is in line with gravitational pull will give the fastest drainage.

Water movement comparison through sand and clay. Soure Coloradostate-edu.

Water movement comparison through sand and clay. Source Coloradostate-edu.

Sandy soils, as one might expect, drains quickly because it consists of only slightly absorptive, small pieces of stone, that allow the water to essentially slide right past.

Clay, on the other hand, is very dense and plasticity. These characteristics, as you might expect, would be resistant to allowing water to pass through, and large bodies of transported clay can redirect horizontally, the flow of water percolating through from above due to it’s slower absorption rate. But what isn’t obvious is that clay’s construction encourages capillary action. The clay body will distribute water throughout its mass, counter to gravitational pull, becoming completely saturated, before releasing excess water through to the material below.

Argillaceous Limestone

Argillaceous Limestone with its horizontal fracturing slows water percolation. click to enlarge

Highly fractured limestone that is still in place, is often is fragmented in a prismatic pattern. However some limestones, like this soft argillaceous limestone to the right, with its high clay content, may fracture horizontally. The type of fragmentation would depend on the stresses upon the stone, the freeze-thaw effects of water and temperature, as well as the material of the stone’s construction. Clay based stones will tend to fragment horizontally and when they do, they are considered platy, and water will percolate more slowly than stones that fracture in a prismatic fashion.

Water movement through soil

The hillside of the Côte is a recharge area for water collection, while the valley below is a discharge area, where excess water is expelled. The water table is at the capillary fringe. Water uses faults and fissures to move quickly into and out of the saturated zone. It is likely there are aquifers, meaning caves which have been cut out of the limestone by carbonization below the Côte, where the water is stored.

 

a small karst aquifer Photo:planhillsborough.org/

A small karst aquifer in Florida. Photo:planhillsborough.org/

Groundwater, the water table, and karst aquifers

In writings regarding Burgundy, very little is said about ground water, other than there are no cellars built underground in Puligny because the water table is too high there. A plentiful water supply may be one of the features that propel the vineyards of Puligny into the ranks of the worlds best. As my diagram above shows, water percolates through the soil and stone. This upper section is called the vadose zone, or unsaturated zone. Slabs of limestone, fissures, faults, and clay bodies all can change the course of the water flow. Each horizon of soil and each layer of stone have their own rate of percolation. With this much limestone, it is very likely there are karst aquifers or large caves caused by the carbonization of calcium carbonate beneath the Côte, but I could find no specific mention of aquifers in close proximity to the Côte. There is a mention in a European Academies Science Advisory Council‘s country report for France, that in Burgundy there are “karsified Jurassic limestone layers” somewhere in the region, but nothing more is elaborated upon.

There is a very famous and massive karst aquifer with seven very deep layers that spans from north of Burgundy across the Paris basin to the English channel. The deepest level of water is brackish. The uppermost section is called the Albian sands sits at than 600 meters, and was first was drilled into in 1840 taking well more than 3 years to achieve. The water there is 20,000 years old, and there has been discussion whether the water should be considered fossil, meaning there is a question whether there recharge from the water above, or not.

 

Next up: Understanding the Terroir of Burgundy, Part 3: Confluence of stone, soil, and slope

 


 

(1) Interestingly, larger stones, especially the flatter, rounded shaped stones that the French refer to as galets, tend move to the surface, probably because of their larger displacement values.

(2) Sand from other parent rock material is likely to be available as well.

Understanding the Terroir of Burgundy: Part 2.1 From Limestone to Clay

© BiVB Latricieres

Latricieres under brewing storm clouds.  photo © BiVB

by Dean Alexander

The weathering of limestone: let it rain

flooding

Rain and Flooding

For the past 35 million years, rainwater has endlessly and relentlessly washed across the limestone escarpment. To varying degrees, the limestone will absorb water through its pores, but stone that has been damaged by ductile deformation is much more easily infiltrated. Faster still, water fills the cracks and fissures created by geologic strain, finding freshly broken calcium carbonate to wetten, and begin the process of chemical weathering called carbonation.

Rain rainwater, it seems is more than just H2o.  From the storm clouds above, H2o binds to with carbon dioxide (CO2) to form carbonic acid (H2CO3). And although carbonic acid is typically a mild acid when carried by the rainwater, it does slowly act as a solvent to the calcium carbonate (CaCO3) that holds the limestone together. This carbonation frees the carbonate from the calcium, and will metamorphose the calcium into calcium hydrogen bicarbonate Ca(HCO3)2, which technically only exists in solution. (1)  The material that remains behind once it is no longer bound by bonds of the stone, is whatever impurities that were in the stone when it formed. This could include clay, fossils, feldspar which is the most common mineral on earth), among many other possibilities.

Nature’s Highly Engineered, Deconstruction of Limestone

Calcium Bicarbonate photo credit: Frank Baron/Guardian

The calcium carbonate in limestone is made solvent by the carbonic acid in rainwater.  The calcium carbonate is metamorphosed into calcium hydrogen bicarbonate  or Ca(HCO3)2. Technically calcium bicarbonate exists only as a water solution. As long as enough CO2 remains in the water, calcium bicarbonate is stable. But once excess Co2 is released, calcium carbonate is dropped out of solution resulting in the scale like on the facet above. photo credit: Frank Baron/Guardian

Calcium carbonate is more soluble in colder temperatures.  If you aren’t paying attention, this, along with so many other pieces of information might seem fairly unrelated. But like everything else, it is an important piece of the puzzle. It is all part of nature’s finely detailed engineering, where every element directly is related to, and influences the next.

This fact that calcium is more soluble in colder temperatures folds beautifully together with the freeze-thaw fracturing of the limestone that I detailed in Limestone: Part 1.2. The acidic water enters the more porous limestone, where it then freezes. This exerts immense internal pressure on the rock, which causes it to split along the pores, can cause various types of fractures within the stone.  Then when the acidic ice within the rock begins to melt, it erodes the stone along the fissures, being aided by the cold temperatures. The more acidic the rainwater, the more minerals the groundwater can dissolve and be held in solution. Interestingly, because lime is alkaline (a base as opposed to acid) it naturally balances the ph of the water, and thus the soil, which is good for the health the vines.

Clay Development = great vineyards

Puligny excavation at Alex Gamble

An excavation of the village cru, Les Grands Champs by Alex Gamble and Francoise Vannier-Petit. According to Vannier-Petit’s analysis, below the first 30 centimeters of dark clay-loam soil, lies a fine-grained, yellow clay. In its most pure form it is typical of transported clay being less than 2 microns, before mixing with heavier soils of increasing size down to an 80 cm depth. Here it transitions to more loosened substratum of “angular gravel” of 2 mm in size, which she also terms “heterometric stones”, providing good drainage for the site. See more at alexgamble.com

Les Grands Champs

Visual observation: Les Grands Champs is located on the eastern edge of the village of Puligny. The land here is be quite flat, with less than a one percent grade.  It sits at the foot of the 1er cru Clavillions (where the road turns to head up hill). Folatieres lies just above that, the bottom of which is denoted by the by the plot being replanted.

Every Burgundy vineyard that is considered to be great has at least some clay and some limestone in their makeup. But that is not surprising since  clay, is the byproduct of the chemical weathering of stone. The silicate materials (essentially the building blocks almost all minerals) in the stone are metamorphosed into phyllosilicate minerals. Putting that more simply: after stone is eroded by acid, some of the weathered material (depending on what the stone was made of) is transformed into a material that will become clay – once it attracts the needed aluminum, oxygen, and water.

Clays first forms at the site (in situ) of the stone that is being weathered, and this typically is a form of surface weathering. This new material is a primary clay, and sometimes referred to as a residual clay. These primary clays tend to be grainy, lack smoothness, and do not typically have qualities that are described as plasticity. As primary clays are eroded, (typically by water) and are moved to reform in another location, they are called transported clays.

This transportation changes the clay’s properties; this is likely because the water carries the lighter, smaller gains together, away from the larger, coarser material that remains in the in situ location. When transported clay reforms, the reformation is called flocculation. This natural attraction that clays have toward homogeneous groupings, are due not only to their similar size but because they carry a net negative electrical charge, which the particles gain by adsorption. Adsorption is not to be confused with absorption, is like static-cling. Items are added, or adhered by an electrical charge, to the grains, not absorbed by the grains.

In flocculation, particles are attracted to one another, by their uniform size (typically very small, under 2 micrometers), and shape (tetrahedral and octahedral sheets). These phyllosilicate sheets organize themselves, layering one upon another, like loose pages of sheet music. Between these silicate sheets, aluminum ions and oxygen are sandwiched. These elements bind together to form a clay aggregate, even in the confluence of water. Clay formations can carry with them, varying mineral components such as calcium, titanium, potassium, sodium and iron and other minerals, making them available to the vines. To say that the chemistry of clay gets very complicated, very quickly, is an understatement.

Transported clay has plasticity, which primary clays do not. When a clay is very wet, beyond its liquid limit, (meaning the most water a clay structure can hold before it de-flocculates), the sheets slide apart, giving clay its slippery feeling. Any thick area of clay found at a location is likely to a be transported clay, as the adsorption characteristic of clay allows it to achieve significant mass.

Sand 0.02 – 2.00 mm in diameter
Silt 0.002 – 0.02 mm in diameter
Clay < 0.002 mm in diameterClay types

Francoise Vannier Petit at AlexGamble

Francoise Vannier Petit, inspects the yellow ocher-colored clay in Puligny-Montrachet, Les Grands Champs.  Clays get their pigmentation from various impurities. Brown clays get their color from partially hydrated iron-oxide called Goethite. This yellow ocher clay gets its color from hydrated iron-hydroxide, also known as limonite. Clay type, however, is not determined by its color, but instead by its chemical and material organization.

Different clay types can be found next to each other or layered on top of one another. This layering is called a stacking sequence. photo source: alexgamble.com

The type of clay that is produced from the weathering of rock depends on the what minerals make up the stone.  In the case of granite (the stone which existed in the Burgundy region, before the creation of limestone), is constructed of up to 65% feldspar, and a minimum of 20% quartz, along with some mica. While quartz will not chemically degrade in contact with the carbonic acid carried in rainwater, feldspar and mica will. Even though they originate from the same stone, these two minerals will metamorphose into two different of types clay, that belongs to two different clay family groupings. Feldspar weathers into Kaolinite clay minerals and mica weathers to an Illite clay mineral. These tend to be non-swelling clays. (3)

I probably spent twenty hours trying to figure out what kind of clay eroded from limestone, before I realized that it would depend on what impurities were mixed into the calcium carbonate when it was brewed up during the Jurassic period.  Limestone can produce any of the four families of clay.

Kandites (of which Kaolin(ite) is a subgroup), are the most common clay type, because feldspar, which is the world’s most common mineral, metamorphoses into it.

The other three clay groupings are smectite, illite, and chlorite.(4) Within these clay family groupings, there are 30 subtypes. As might be suggested by the example of the weathering of granite above, it is very common for different kinds clays reside adjacent to, or in layers with other clays. This layering of clay types is called a stacking sequence, and it can occur in either ordered or random sequences. Each are attracted to formations of its own type, by size weight, and electrical charge.

The Effect of  Weathered Limestone on Soil Quality

effect of lime on Clay

effect of lime on Clay

There are a number of significant benefits to the high levels of limestone in the soils of Burgundy. The world over, farmers make soil additions of agricultural lime (which is made from grinding limestone or chalk), in order to balance and strengthen their soils. These are additions that are unnecessary in Burgundy.  Soil salinity is increased by the calcium bicarbonate that is released by chemical weathering of limestone. This increase in soil salinity (which raises the pH) of the soil, is cited as a condition for the flocculation of the clay, allowing the phyllosilicates (clay minerals) to bind together into aggregates. But of course, citing a high ph is required for flocculation (as I have seen written by several authors) this is the chicken or the egg debate. The flocculation requires a low pH environment to occur because it creates that environment in process of its development.

Lime additions to agricultural lands are also beneficial in that it increases soil aeration, which in turn improves water penetration. The calcium loosened soils allow for better root penetration, and because of that root growth is improved. Additionally, agricultural lime strengthens vegetation’s cell walls, increases water and nitrogen intake, and aids in developing enzyme activity. Too much lime (and its accompanying salinity) in the soil, however, can be lethal to the vines, and various rootstock has been identified as being more resistant to the effects of high levels of limestone in the soil than others.

This loosening of soil by addition of lime/calcium carbonate is caused by the disruption of the alignment of the clay particles. Rather than doing a poor job paraphrasing an already excellent article from soilminerals.com, called “Cation Exchange Capacity,” which will I quote below.  To put the article in a frame of reference, it explains to farmers interested in organic and biodynamic farming, the proper mineral balance for healthy soils. These are conditions often exist naturally in the best sections of the slope in the Cote d’Or.

“Because Calcium tends to loosen soil and Magnesium tightens it, in a heavy clay soil you may want 70% or even 80% Calcium and 10% Magnesium; in a loose sandy soil 60% Ca and 20% Mg might be better because it will tighten up the soil and improve water retention. If together they add to 80%, with about 4% Potassium and 1-3% Sodium, that leaves 12-15% of the exchange capacity free for other elements, and an interesting thing happens. 4% or 5% of that CEC will be filled with other bases such as Copper and Zinc, Iron and Manganese, and the remainder will be occupied by exchangeable Hydrogen , H+. The pH of the soil will automatically stabilize at around 6.4 , which is the “perfect soil pH” not only for organic/biological agriculture, but is also the ideal pH of sap in a healthy plant, and the pH of saliva and urine in a healthy human.” soilminerals.com

Mud is the problem, lime is the solution

On construction sites, mud is a problem, and lime is the solution.

The industrial of use of limestone to control wet and unstable soil

The soil strengthening properties of lime is well known by the construction industry. It is used as a soil stabilizer in the construction of buildings and roadways, as well as being used to stabilize wet ground to improve the mobility of trucks and tractors. In the vineyard, soils with high levels of limestone provide the good porosity, soil structure, and drainage to clay soils, and as this construction advertisement depicts, the same for mud/dirt soils as well.

Lime is also the binding agent in cement. The first known use of lime in construction was 4000 BC when it was used for plastering the pyramids, and later the Romans extensively used lime in the preparation of mortar for various constructions. They found that mortars prepared from lime, sand, and water, would harden to a man-made limestone, with exposure to the carbon dioxide provided by the air. This, of course, sounds very familiar, knowing the formation and chemical weathering of stone.


 Next Up Soil Formation: Part 2.2, Soil, Slope and Erosion

NOTES

(1) I should note, that within the span of this short paragraph, carbon has seen several forms: in the air (in carbon dioxide CO2), as an acid (in carbonic acid CO3) carried by water, in stone as calcium carbonate CaCO3, as a mineral bi-product (as calcium bicarbonate Ca(HCO3)2 which exists in liquid solutions. This is all part of the carbon cycle, where carbon is regenerated in the air we breath, the water we drink, the earth we grow our food in.

(2) The fact that CO3 is now carried by water, is important in terms of vineyard development.

(3) Kaolinite clays are the type used in pottery.

(4) As Granite was the primary stone formation in the region prior to the development of limestone, it is likely that Kaolinite and Illites are the most common clay families in Burgundy today.

Understanding the Terroir of Burgundy: Part 1.2 Limestone: stress, deformation and fracturing

by Dean Alexander

The first steps toward vineyard formation

The world was a very different place 160 million years ago when the limestone was formed. Dinosaurs roamed the earth and Pangea was breaking apart.

The world was a very different place 160 million years ago when the limestone of the Cote d’Or was formed. Dinosaurs roamed the earth and Pangea were breaking apart.

Burgundy’s story really is one of stone into the earth, and pivots on a cast of geological stress, sub-freezing temperatures, and the simple, transformative power of water. Just how the forces of nature may have acted upon the limestone and transformed it into the great wine region it is today, is the subject of this article. Meanwhile, the ultimate goal of this series explains the intimate relationship limestone has with the wines of Burgundy.

I suspect that we all have this image of the Côte, post-Fault Event (however long that took), to be this raw 400-meter face of sheared limestone. But even then, the Côte was not a solid piece of stone. The incredible extensional forces the broke the Côte d’Or free from the Saône would have caused significant tension fracturing throughout the Côte before this much more massive fault gave way.

Just Add Water

just add water

just add water

This tensile fracturing, which surely was extensive, would allow rainwater to deeply infiltrate these fine crevices of the stone. And then, upon each surface that the water contacted, depending on the specific porosity and permeability of the limestone, rain water would penetrate the surface of the stone. This contact with water would set the stage for two very different yet significant developments in the stone.

With winter temperatures below freezing, the water in the stone will expand between 8 and 11 percent. This will yield 2000 pounds per square inch, or 150 tons per square foot of internal pressure which is more than enough  to cleave the stone. Geologists call this frost wedging, a form of mechanical weathering which breaks apart the stone due to thermal expansion and further with the eventual contraction. Thermal expansion has a culprit in shattering the stone: the cold. Most materials are inherently brittle in colder temperatures, and the limestone which has more elastic than brittle tendencies is more vulnerable to fracturing in freezing temperatures. Frost wedging is so successful in nature that the stone industry mimics it as a non-explosive technique to separate pieces of stone.

The effect of successive freeze thaw cycles, even upon undamaged exposed stone can cause the development of micro-fissures that influence the stone’s fatigue strength, and can produce vertical cracking called exfoliation joints, as well as flaking, and spalling. All along the Côte, there are numerous scars on hillsides where limestone has in the past loosened, to slide off of even moderate slopes, sending scree down the hillside to rest at the curb of the slope. Geologists refer to this rubble pile as colluvium, and it has proved a near perfect vineyard soil solution. The sliding and falling of rock further degrades the stone, abrading it as it slides, and breaking as it falls, allowing fresh broken surfaces for water to act on. Frost wedging which in part created this colluvium rubble pile, is considered mechanical weathering, and is the first development that I mentioned water would bring. Equally important to vineyard formation, is the second significant development that rainwater brings, is chemical weathering. The acid carried by the rainwater, will metamorphose these freshly broken limestone surfaces. And like magic, it will slowly dissolve the calcium carbonate which binds the stone, leaving behind clay minerals and other material.  (This process will be covered in Part 1.3 Clay and Soil Development)

Exfoliation and Other Theories on Geologic Structures with Unobservable Change

Gilbert's 1904 exfoliation weathering and unloading theory explained. Girraween National Park, Queensland

Gilbert’s 1904 exfoliation weathering and unloading theory explained. Girraween National Park, Queensland

Consider for a moment: most significant geologic changes occurs over a time frame that is far longer than the entire the evolution of mankind. This fact alone might best explain the difficulties of studying events that happen so slowly that change is not observable. These are geologic forces that can not be seen, felt, or measured. If we didn’t have evidence that these changes had occurred, we would

Like this granite, softer, more impure limestone can be prone to spalling, in part because of its porous nature. Stones, like granite, and softer limestones that have a significant amount of feldspar in their makeup, are more brittle because feldspar, and its bonds, are more brittle. Conversely, the calcium carbonate in limestone makes the material more elastic, because the chemical bonds of CO3 will tend to move or realign if the stress upon them is long and gradual. So the makeup of each limestone is critical to how prone it is to fracturing.

Like this granite, softer, more impure limestone can be prone to spalling, in part because of its porous nature. Stones, like granite, and softer limestones that have a significant amount of feldspar in their makeup. Feldspar, the most common mineral on earth, and its bonds, are brittle than calcium carbonate. Conversely, the calcium carbonate in limestone makes the material more elastic, because the chemical bonds of CaCO3 will tend to move or realign if the stress upon them is long and gradual. So the makeup of each limestone is critical to how prone it is to fracturing.

never know they were still continuing to occur around us. The scale of time and shear size and immobility of the objects makes many traditional scientific methods impossible.

Exfoliation Theory: G.K. Gilbert 1904

We know that exfoliation joints exist, but scientists are at odds about how they occur. It is agreed that mechanical strain results in large horizontal sheets of stone separating itself from the mother rock. Half Dome in Yosemite has achieved its shape in this manner. The first, and once long-held theory, was put forth by the ground breaking U.S. geologist Grove Karl Gilbert.  Gilbert’s theory of Mechanical Exfoliation concerned stone formations that had previously been buried in the earth’s crust, which were later were forced to the surface by geological up-shifts. The theory explained that the removal of the overburden (the weight of the rock or earth above) had caused unloading of stress in one direction. The resulting release of stress once on the surface and not confined upwardly, caused expansion and tensile cracking along unloading joints, eventually creating loose sheets of stone on the upper surface of these rock structures. These outer layer of stone were thusly being exfoliated. This website for Girraween National Park in Queensland, Australia, has an excellent explanation of exfoliation weathering.

Challenges to Exfoliation Theory

However, this theory has had it challenges by the mid 20th century, and is to some extent (depending on the point of view), muted or discredited.  Situations were sited that didn’t fit all of the theory’s criteria, like rocks that with exfoliation joints which have never been deeply buried, and evidence that many exfoliation joints exist in compressive stress environments, rather than being produces by extensional stress as the theory suggests. Alternative theories are thermal expansion, (and even wide diurnal expansion), and hydraulic expansion, , (which I discussed above with frost wedging), compressional stress, and in the case of Half Dome, the weight of gravity, or a combination of all of the above, including exfoliation weathering.

Along the same lines, theories revolve around minerals that are created in an anaerobic environment. These stipulate some minerals molecular structure are changed (metamorphized) when exposure to oxygen, creating new minerals. While oxygen is the most common element in the earth’s crust, most of it is bonded with silicates and oxide materials and is not free to act as a weathering agent. But when minerals are exposed to free O2 above ground, they undergo chemical weathering, that produces new minerals that are stable on the surface.  The most obvious example is when iron ions lose an electron with exposure to oxygen, rust is formed.

Bedding planes

bedding fold types: Caused by compressional stress. Although extensional stress is the major shaper of the Cote, there are some folds in the North-South direction, due to compressional stress.

bedding fold types: Caused by compressional stress. Although extensional stress is the major shaper of the Cote, there are some folds in the North-South direction, due to a compressional stress of bedding plates pushing against one another.

In many ways, I’ve put the cart before the horse by talking about the escarpment, before covering even more fundamental ideas. But that is how storytelling goes: sometimes you have to fill in the back story.

The world was a very different place 160 million years ago. This was five million years before the Allosaurus and Apatosaurus (formerly known as the Brontosaurus) roamed the earth. The limestone of the Côte, being a sedimentary material, was laid down in big, flat, shallow beds between the reef barrier that protected the lagoon, and the shore. Each layer was put down, one at a time, chronologically by age, marking millions of years. As the seas receded, and this is the main point, this would become a wide, flat valley of young, sedimentary limestone. It is likely that this bedding would eventually, be completely covered by wind-blown soils. We don’t know what happened to this young Burgundian stone in the intervening 130 million years between formation and the Fault Event, 35 million years ago, but it is unlikely it remained there unchanged. As geological stress acted upon the bedding, it would be pulled, pushed, deformed, and in all likelihood, in some way, fractured.

Author’s Note: For the remainder of this article, I will describe the stress and deformation, and potential fracturing of the stone in the body of the text, and in the photos I will show some of the results (that I am aware of), of that stress. Hopefully the two together will paint a complete picture.

It takes more than just ‘X’ to fracture

Bedding dips Bedding planes. All bedding started out horizontal, but through various stresses, the bedding planes often shift and compress one another causing folds or change their orientation.


Tilted Bedding Planes: While all sedimentary bedding was laid out horizontally, various stresses can shift the bedding planes into other orientations. Geologist measures the tilt by dip, the up/down angle, and strike the percentage off of an east-west axis.

I would love to be able to write that a particular limestone will fracture under the “X” conditions, but just doesn’t seem to be that simple. First, there are too many variables. How stone reacts to geological stress is directly related to its composition and construction as well as: its temperature, the amount of stress, multiplied by the duration of  stress. Most materials tend to be more elastic under higher temperatures and more brittle in low temperatures. It would be reasonable to assume that there was significantly more geological fracturing during ice ages because stone is more brittle in cold temperatures. At least in warmer temperatures, calcium carbonate stones tend to have good elasticity, depending on how pure their construction, as the chemical bonds in CO3 will move if pressure is applied very slowly. However, that elasticity is finite before the stone is structurally damaged as it passes its elastic limit; but more on that later.

Secondly, like I mentioned before, science cannot measure the stress, but rather the deformation due to the stress. For this geologists use a strainmeter, which they measure changes in the distance between two points. For greater distances technology has brought the laser interferometer. These tools allow the scientist to measure frequencies that represent deformation.  Over short periods of time, they record tides (I had never before considered the stress created by a 1.5 quintillion tons of water moving position above earth) and the seismic waves of earthquakes, while over longer periods of time, it can record the gradual accumulation of stress of rock formations.

The mission of this article? What I am looking for here, are some kind of answers these two questions: What conditions would make it possible for vine roots to bed into limestone bedrock? and What limestone types will fracture enough to allow this to happen? Anything learned along the way will be a bonus.

Stresses and the resulting strain

The ductile bending of this folded limestone was made under compressional stresses for a considerably long period of time. Ductile folds are not elasticity as, if released, this rock would not return to its original shape. Note the fractures that have developed almost vertically through the layers of stone.

The bending of this folded limestone was made under compressional stresses over a very long period of time. This stone. well beyond its elastic limit, has experienced a high degree of ductile strain, and is now brittle and structurally degraded. Note the fractures that have developed almost vertically through the layers of stone.

Stress causes strain of various types. Like I mentioned before, we are not able to measure the stress itself, rather only its effect by measuring the stone’s deformation. Below are the basic stresses upon objects and the resultant strains and deformations associated with them. Any deformation is considered flow (as science calls this) and it is domaine of an interdisciplinary study called Rheology. Here it is again, more simply, because its getting more complicated: Stress first.  It, in turn, causes strain. The result can be deformation, and this deformation is studied as if it were a liquid: as flow by Rheologists (a group of engineers, mathematicians, geologists, chemists, and physicists), who work together in an attempt to answer questions that transcend all of these disciplines.

6 Most Common Geologic Stresses (the first two are the most relevant to Burgundy)

  • Tensile, Tension, or extensional stress which stretch the rock or lengthen an object, will cause longitudinal or linear strain, and its effect is to lengthen an object, and can pull rocks apart. Like a rubber band pulled longitudinally, this is known as extensional rheology. As the rubber band breaks, that is called shearing flow. Rocks are significantly weaker in tension than in compression, so tensile fractures are very common. Tension stress formed the Côte d’Or.
  • Compressional stress that squeezes the rock and the resulting strain shortens an object. This too can be a linear or longitudinal strain. Stone under compressional stress can either fold (as in the photo to the right) or fault.
  • Normal Stress (can be either compressional or extensional) Normal stress that acts perpendicular to the stone.
  • Directed stress is typically a compressional stress, that comes from one direction with no perpendicular forces to counteract it. The higher the directed pressure the more deformation that occurs.
  • Lithostatic> and hydrostatic stresses are the compressional pressure of being underground or underwater. The force of the stress is uniform, causing compression from all sides.
This limestone jutting out of the vines in the Puligny vineyard, Les Combettes. Wine writers typically cite this common rock features as evidence of shallow soils, but these rock features are more likely a fold (plunging anticline) caused by compressional stress.

Wine writers typically cite these limestone outcroppings as evidence of shallow soil. But these rock features are more likely a fold (plunging anticline) caused by compressional stress. Location: Puligny, Les Combettes.

Interestingly, the effects of hydrostatic stresses upon an object are mitigated by oppositional forces. For example, the stress from below counteracts much of the force from above, and the forces from the right side counteracted by those from the left as they push against each other. So unlike directed stress, (the kind of stress that a 2 ton object exerts on top of a man), hydrostatic stress is like a scuba diver in the ocean. The stress of water upon the diver can be the same as the heavy weight upon the man, but because of counteracting stresses, strain is not expressed in the same way.

  • Shear stress is that which is parallel to an object. Shear strain (caused by shear stress) changes the angle of an object. It can cause slippage between two objects when the frictional resistance is exceeded, or even failure within an object. Faulting is an example of slippage under shear stress. I would be remiss to note that faults in Burgundy, at least to my anecdotal eye, often occur between limestone types.

 

Coaxial strain

Coaxial strain

 

The Magnitude of  Strain

Elastic strain and ductile deformation

stressesThere are two levels of strain. Elastic strain, in the effects of the strain, are reversible. The stone will change shape or deform under stress, with minimal damage to its structure, and then return to its original shape and position.

Ductile strain, is the area of strain once past the elastic level. The stone is now developing microscopic fissuring, and the stone can not return completely to its original size, shape, or position. Although the stone may not appear to be visibly damaged, any deformation into the ductile range, will harm the stone’ structural integrity. Additionally, in comparison to the deformation of the stone in the elastic range, the speed and ease of ductile deformation increases quickly (in structural geologic terms).  The deformation is now the result of micro-fissures that have emerged throughout the stone, and are now both propagating and enlarging. It is during this phase of rapid deformation that the stone can achieve dramatic folding from what had previously been flat, sedimentary stone.

By The Numbers: limestone limits

Elasticity in stone

Elasticity in stone

Author’s note: The measuring of deformation and the related stress involved becomes a bit more technical, and requires a number of lingo words to be used in the same sentence. I resist this as much as possible, because it requires the reader to be very familiar with the terms. Skip ahead if this doesn’t interest you, but it gives a numerical frame of reference for limestone fracturing.

The deformation under applied pressure is called flow, and the material’s resistance to deformation is measured (in newtons). The measurement of a stone’s elasticity is called it’s Elastic Modulus  (a.k.a. Young’s Modulus).

Elasticity of rock groups. Click to enlarge

The elasticity of rock groups. Click to enlarge

The Elastic Modulus measures the tensile elasticity, meaning when a material is pulled apart by extensional stress.  This resistance to deformation is expressed in gigapascals (GPa) which are one billion newtons per square meter. 

Additionally, there is Bulk Modulus, the measurement of a stone’s lithostatic (compressed from all sides) elasticity. This is expressed in Gigapascals, (GPa) or one million newton units.

And Shear Modulus, also known as the Modulus of Rigidity, in which the elasticity of a stone under shear forces is measured.  It is defined as “the ratio of shear stress to the displacement per unit sample length (shear strain)”.

Scarp Cutaway. Click to enlarge

Scarp Cutaway. Click to enlarge

I gave the MPa compressional strength (loads that tend to shorten) of various limestone types in part 1.1. Note here MPa is used, or one million newtons per square meter. The elastic modulus of most limestone can be as low as 3 GPa for very impure limestone (we don’t know what was sampled), and up to 55 GPa depending on purity of the calcium carbonate. As a comparison of elastic modulus: Dolomite (limestone with a magnesium component) typically ranges between 7 to 15 GPa, while Sandstone typically runs 10 to 20 GPa.

  • click to enlarge

    click to enlarge

    General Limestone Modulus Ranges (the range of deformation before fracture)

  • Elastic modulus range: 3 GPa – 80 GPa  
  • Bulk modulus range: 5 GPa – 66.67 GPa
  • Shear modulus range: 3.5 GPa to 33 GPa

 

The strain rate is important: which is expressed as elongation over time (e/t). The longer the period of time, the more the material can “adapt” to the strain. The faster the stress is applied exceeding the plastic elastic limit, the shorter the plastic region. The plastic region fracture where the material breaks and is considered brittle behavior.

  • Brittle materials can have either a small (or a large) region of elastic behavior, but only a small region of ductile behavior before they fracture.
  • Ductile materials have a small region of elastic behavior and a large region of ductile behavior before they fracture.

 

From Strain to Total Failure of Stone

The description of how stone reacts to crushing pressures reminds me of those submarine movies, where the hull is slowly being strained with a chorus of creepy groaning sounds, rivets popping and water spraying from leaks in the hull. In the laboratory, geologists study stones they crush, in order to understand what has occurred to rock materials over hundreds of thousands, to several million of years.

Infinitesimal strains refer to those that are small, a few percent or less, and is part of a mathematical approach material that is “assumed to be unchanged by the deformation” (Wikipedia).  As deformation increases, micro-cracks and pores in the stone are closed and depending on the orientation of the pores in relation to the direction of the stress, this can cause the stone to begin to deform in a coaxial manner. This non-linear deformation is obvious in weaker or more porous stone.

The goal is to explain how this happens in limestone with high calcium carbonate

The goal is to explain how this happens in limestone with high calcium carbonate content. photo alexgambal.com

While in the elastic region, stone adjusts to the pressure applied to it. Micro-cracks don’t appear in the stone until it reaches the 35%-40% way-point in elastic region. At this point structural strain is largely recoverable with little damage. At 80% of the elastic limit, micro cracks are developing independently of one another, and are evenly dispersed throughout the stone’s structure, despite the fact that the stone is at maximum compaction with no volume change. As the stone nears its elastic limit, micro-cracks are now appearing in clusters as the their growth accelerates in both speed and volume. The stones appearance and size remains intact as it passes its peak strength, although the structure is highly disrupted. The crack arrays fork and coalesce, as they begin to form tensile fractures or shear planes, depending on the strength” of the limestone.(1) The rock is now structurally failing, and considered to have undergone “strain softening”.  Additional strain will be concentrated on the most fractured, weakest segments of the stone, creating strain and shear planes in these specific zones, which as it nears the fracture point will essentially become two or more separate stones, ironically bound together only by frictional resistance and the stress that divided them. information source: Properties of Rock Materials, Chapter 4 p.4-5, (LMR) at the Swiss Federal Institute of Technology, Lausanne

The Bottom Line on the Fracturing of Limestone

Roche de Solutre and Vergisson, are large, tilted bedding planes. What little information that I have found of their formation (non-scientific) claims these are plateaus which raised when the Saone Valley was formed, and have later tilted to the East. Plateaus are often formed by magma pressure causing the ground swell upwards, or by glacial erosion. The theory that 400 meters of stone were reabsorbed back into the earth by tilting, sounds like sketchy science to me. I would consider a second option more likely: only one end of this structure was pushed above ground by geologic forces.

Roche de Solutre and Vergisson, are large, tilted bedding planes. What little information that I have found of their formation (non-scientific) claims these are plateaus which raised when the Saone Valley was formed, and then later “tilted” to the East.  The theory that 400 meters of stone were reabsorbed back into the earth by “tilting”, sounds like sketchy science to me. I would consider a second option more likely: only one end of this structure was pushed above ground by geologic forces.

The truth is that we don’t have any records detailing the condition of the limestone base that lies below the topsoil. Certainly the limestone base has been exposed often enough over the past century, that had some academic organization wanted to catalog this kind of information, there would now be a large database to refer to by now. Moreover this would be a substantial advance in the knowledge of how to farm these vineyards. Today, the most progressive vignerons are now making these inquiries themselves, digging trenches to find out what lies below in order to make the best replanting and farming decisions possible. But it is unlikely that even these recent efforts are being catalogued, as they investigated.

Vineyard Development: Limestone

Tilted bedding plane, whether a plateau as one source describes or not As a tilted bedding plane, The Roche (Roc) de Solutre and Vergisson, despite their distance South of the Cote de Nuits, and their slightly more youthful age, gives an unique glimpse into the layers of limestone in Burgundy. It reminds us, that whatever the top layer is, there lies different strata just below it. Click to enlarge

Tilted bedding plane, whether a plateau as one source describes or not
As a tilted bedding plane, The Roche (Roc) de Solutre and Vergisson, despite their distance South of the Cote de Nuits, and their slightly more youthful age, gives an unique glimpse into the layers of limestone in Burgundy. It reminds us, that whatever the top layer is, there lies different strata just below it. Click to enlarge

Limestone fracturing and shallow soiled vineyards

Since deeper soils do not require the vine to penetrate the bedrock in order to have a successful vineyard, fracturing there is not required for vineyard vitality.

However any vineyard where there is shallow soil, the limestone below must be compromised structurally, to some degree, for the vines to penetrate the stone. In this way, the vines themselves are a contributor to mechanical weathering of stone in the vineyards. Limestone varieties with a high percentage of impurities, are typically more easily fractured; although they may actually be soft enough, or porous enough stone for the vines to penetrate on their own.  It is documented that composite formations with heavy fossilization (like crinoidal), or clay content (like argillaceous limestone)  are less elastic than purer limestones with high levels of CaCO3, and are much more friable. You can read about limestone construction in Limestone: part 1.1.

With a harder stone, would significant ductile deformation with fissuring make the stone weak enough for the vine roots to penetrate?  Or does a limestone based vineyard need to be significantly fractured before vines can sufficiently take root? That answer to this question is not apparent with the information available at this time, but the answer is probably yes.

Mazy and Ruchottes Chambertin with dip and strike oriented faults. Significant outcropping has emerged from this hard Premeaux stone at the convergence of these faults. Interestingly its both parallel and perpendicular to the extensional, horizontal faulting

Mazy and Ruchottes Chambertin with dip and strike oriented faults. Significant outcropping has emerged from this hard Premeaux stone at the convergence of these faults. Interestingly its both parallel and perpendicular to the extensional, horizontal faulting

Vineyards like Mazy-Chambertin and Ruchottes-Chambertin give evidence that the more brittle Premeaux limestone (with its lower compressive strength, and higher porosity), if fractured enough, can support vineyards, despite there being very shallow topsoil. There are a number of linear, east-west oriented, limestone outcroppings in these two vineyards, indicating this area has seen significant compressional stress to the bedrock there over the last 35 million years, in addition to the tensile faulting caused by extensional stress that created the region. These two stresses would have created vertical dip joints, and horizontal, strike joints, and very possibly diagonal oblique joints, and fissuring in the bedrock. Enough for the vines to survive well enough for these two vineyards to be awarded grand cru status in the late 1930s.There has been a question in my mind whether Comblanchien, which is so dense that water cannot penetrate enough to effect freeze thawing, and is also very elastic due to its 98% calcium carbonate content, would fracture enough in a vineyard location to support a vineyard in shallow soils. In fact that has been a driving question throughout this piece, and which I was inclined to believe the answer was no, until evidence proved otherwise.  Apparently that has happened. 

The Rise of Colluvium

In terms of vineyard soil development itself, geologic pressures have worked extensively to prepare the limestone bedrock. Primarily with extensional stress, but also exerting compressional stress, the strain significantly weakened and fractured the limestone bedding. This deformation and the ensuing fracturing allowed water to infiltrate its cracks and crevices. During periods of cold weather it would freeze within the fissuring, causing frost wedging. Exfoliation would ensue, ultimately causing significant limestone debris to be pulled away by gravity, itself a powerful force of mechanical weathering, to slide (and tumble) down the hillside.  As the stones fell, they would further break and abrade into yet smaller pieces. Abrasion is another agent of weathering. There they would stop at the curb of the slope, where eventually they form deep, limestone-based “colluvium” soils. This is what Coates is speaking of when he wrote “rock and more limestone on the section closest to the over-hang, and there is some sand” in AmoureusesThese are the colluvium soils that would with enough time would generate the vineyards upon the the red grand cru vines of the Cote de Nuits would grow.

But first, the story of chemical weathering would have to play out, creating clay and soil needed to feed the vines. The slopes of the Cote d’Or would slowly evolve geologically for millions of years, awaiting the arrival Roman agriculturalists who would recognize and exploit the vinous wealth of this thin strip of the hillside.

Next up: Part 1.3 Amoureuses and Parallel Evidence of Shallow Soils over Comblanchien

 

Please feel free to comment, like, follow, share, or re-blog this or any of this terroir series!

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(1) Because it is often difficult to distinguish between the different types of fractures and  faulting once the fracture has occurred, I will leave it at this. There are 3 kinds of fractures born from the three major stresses: Shear, tensile, and extensional.

(2) I have not been able to determine if  crystallization is a definition of Comblanchien limestone, or if the Comblanchien limestone in the villages Corgoloin and Comblanchien just happen to have been metamorphosed into marble, and that is why it is quarried there.

Previous articles on Terroir

Limestone Construction: part 1.1 (click here)

Introduction to Terroir (click here)

Preface to my article on Terroir (click here)

Marl: The Most Misused and Misunderstood Word in Burgundy Literature? (click here)

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Preface to my upcoming article: “Understanding the Terroir of Burgundy”

(Opinion) and the ensuing quest for answers.

travel-france-pic-liberte

Wine literature champions the one half of one percent of the top vineyards, and the very top producers. What about the wine for the rest of us?

Despite the scores of books written about Burgundy, if you really break down what is being written specifically about the each climate, the information can be pretty sparse. For a handful of the greatest vineyards, extraordinary efforts are made to explore the grandness of these few plots.(1)  However these vineyards probably represent less than one half of one percent of Burgundy. Little coverage is given to the physicality of the rest of Burgundy’s sites, including many highly-regarded premier crus. Beyond listing most vineyard’s size, what the name means in French, sometimes an inane fact (like some wild bush used to grow in that spot) and who the top producers are, most crus don’t seem to warrant the effort. How does Puligny’s Les Combettes differ from Les Champs-Canets, which sits directly above it? It is not likely you find the answer by reading a book about Burgundy.

Of these vineyard entries, writers typically ignore the soil makeup and limestone below; the most primary elements of terroir. Perhaps this is due to a lack of information(2). However, I have no doubt that if as much effort was given to researching these appellations as is given to tasting Armand Rousseau’s latest barrel samples, we’d have a lot more understanding about Burgundy than we do today. Typically when a comment regarding a particular vineyard’s soil is made by a wine writer, it is simply as a notation, with no connection to the style of  wine that comes out of that vineyard. It sits there like a pregnant pause, as though it were quite important, but no explanation follows.  And that explanation is what I hope to supply by my upcoming article. I can’t do what the top wine writers can: go to Burgundy and walk the vineyards with the winemakers, talk to the professors at Lycée Viticole de Beaune. But I wanted these answers for myself; what it all that means: the limestone and “marl” and clay, and what did for the wine. If I could. Did I dare?

While I am critical of the much of the wine writing produced – for its lack of deeper educational and intellectual content, I understand that wine writers must produce what consumers are willing to pay for. We are a consumer-driven society, and readers are really looking for buying guides wrapped up in a little bow of information. The capitals of 19th century Europe were famed for their starving intelligentsia, but no one wants to scrape-by in a land of plenty, regardless how romantic. Wine writers write what the public wants.

The beginning

Way Too Geeky!

Way Too Geeky!

After more than a year of researching Burgundy vineyard information for the marketing part of my job, I thought I could do a quick write-up about the terroir of Burgundy. I had come to some interesting conclusions and felt I could write a piece with a unique perspective on vineyard orientation, slope, the general soil types determined by that, and how it all relates to a wine style.

It was all going along quickly and easily, until I wanted to clarify a couple of points about geology. What had initially looked like a weekend project, has taken 9 months of daily work. This article has become something of a Leviathan, but the exploration has taken me to uncover some enlightening information, as the pieces started falling into place. The original piece first became two parts, and ironically, now it is four parts, each divided into articles of a more manageable size of 2,000 to 4,000 words. The result of this is untold hours of research and writing.

Unfortunately, sections of Part One have ended up being so technical that I no longer really know who will want to read it. Any hope of an audience is slim. Most wine professionals are so burnt by the end of the week, that they would rather paint their house than read about wine. However, this is a unique article that looks at the breadth of the factors that influence vine growth in Burgundy, and ultimately influence wine character.

An example of a map showing the vineyards I'm highlighting, as well as the soil and limestone base it sits upon.

An example of a map I developed, showing the vineyards I’m highlighting, as well as the soil and limestone base it sits upon.

A Path of Discovery and Frustration

One of the first surprises was difficulty justifying the satellite images with some of the vineyard maps that I had been so diligently studying. Sometimes they just didn’t look like the same place. The vineyard maps often gave little sense of topography of the hillsides, despite paying particular attention to the elevation lines. I believe that the amount of slope in vineyards that are not terraced, like in Burgundy, is critically important to the profile of a wine.

What looked like roads on a map, at times were not, and in many places, there were entire sections which were shown as vineyard were actually unplanted, inhabited only by trees, scrub, or rock. This I found to be very illuminating information regarding adjacent vineyard land, and how that might define character. At times, the shapes and sizes of vineyards depicted on maps appeared to be different from the photos, perhaps changed to fit the artist’s needs.  After a while, I started making my own maps using Google Maps’ satellite images, and adding the information that I found relevant to the needs of my job. Perhaps the most telling visual information has come by utilizing Google Maps’ street view, to see a vineyard and its slope, the topsoil, quickly and easily, and often from multiple angles. It is an amazing tool, I highly recommend using it in addition to maps when studying wine regions.

Am I a Skeptic or Just Paranoid?

Marl table. With one extreme being all clay and the other being all limestone, marl is a mix of both.  Courtesy of wikipedia.

Marl table. With one extreme being all clay/mud and the other being all limestone, marl is a mix of both. Courtesy of wikipedia.

I noticed that the information I was reading, from multiple sources, wine writers, importers, etc, was all starting to seem repetitive, using similar wording, ideas, phrasing. Increasingly, the information seemed more and more borrowed, shallow and canned. For instance, it is common for a writer to state that a vineyard is “a mix of limestone and marl” or the vineyard is made up of “marly clay.” And then there was this from one of the definitive Burgundy reference books regarding the soils of Mazy-Chambertin: “there is a lot of marl mixed in the with the clay and limestone.”

Marl is generally defined as a mix of clay and limestone. When they refer to limestone in this fashion, they don’t mean solid stone, they mean rock that has been mechanically eroded, of varying sizes (from a fine sand to fairly large stones) that are mixed into the soil.  The ratio of these two major elements of marl, can be a range of 35% of one, to 65% of the other.(3) The more I read, the more I question what I am reading.(4)

Below is an example kind of “soil information” that I’m talking about. At first blush the passage below sounded like I’d found the holy grail of explaining what kind of soils for which Pinot and Chardonnay were best suited, but later I realized it was anything but.  The following was written by an authority on the subject.

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“• Pinot Noir flourishes on marl soils that are more yielding and porous, that tend towards limestone and which offer good drainage. It will produce light and sophisticated or powerful and full-bodied wines, depending on the proportion of limestone, stone content and clay on the plot where it grows.”
“• Chardonnay prefers more clayey marly limestone soils from which it can develop sophisticated, elegant aromas in the future wine. The clay helps produce breadth in the mouth, characteristic of the
Bourgogne region’s great white wines.”

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With the Pinot, he starts off well. Clay with high levels of calcium carbonate (limestone) content loses its plasticity, which makes clay more yielding and porous; that part makes sense. The second sentence somewhat contradicts the first, in that it suggests rightly that as the clay content goes up, the wines it produces becomes more full-bodied. However, as the clay content goes up, the yielding and porous nature of the soil will correspondingly decrease.  To make this passage more accurate, he should have led with drainage. The porosity of the soil allows drainage: in other words, it has a causal effect of good drainage. It is not an axillary attribute as he suggests when he writes “and which offer good drainage.”

Of Chardonnay, he wrote that the varietal “prefers more clayey marly limestone soils. First off, what does that mean anyway? If the soil is marl,(5) we already know that it has clay and limestone. A marl soil can be a clay-heavy marl, or a limestone-dominate marl, but it can not be a “clayey marly limestone soil.”  Secondly, it seems that the writer is suggesting that Chardonnay does not do as well as Pinot Noir in porous limestone dominated soils, and vice-versa. I believe vineyards like Les Perrières in Meursault, that have very poor, and very porous, limestone soils, with little clay content, contradicts that notion. Additionally, in Chassagne Montrachet, Chardonnay has replaced much of the  Pinot Noir on the upper slopes of the appellation, while Pinot Noir has remained in the heavier, clay-infused soils lower on the slope.

“Now every piece of information had to pass the smell test, and preferably it needed to be corroborated by another source, that clearly wasn’t of the same origin.”

Skeptic: everything must pass the smell test.

Skeptical, now everything must pass the smell test.

I plodded on with my inquiry. Now every piece of information had to pass the smell test, and preferably it needed to be corroborated by another source, that clearly wasn’t of the same origin. I had read enough to identify “family trees” of bad information, and I often believed that I could often identify the original source.  Just how easy it is to pass-on incorrect information is illustrated by this next example. I found an error (in my opinion) in one Master of Wine’s book on Burgundy, saying that the “white marl” of a vineyard was found on the upper slope, producing a richer, fuller wine, and while the calcareous (limestone) soils were down below, and produced a lighter wine. It was an obvious mistake if you just thought about it for a second, as the forces of gravity and subsequent erosion drive clay to the lower-slopes where it reforms via flocculation. Later I would find the same information, but in more detail, in another Master of Wine’s article, again containing the same error.(6)  The source of the error was either a mis-translation of a conversation with a vigneron, or a typo. While this is a simple mistake, having two of our most revered Master of Wines citing the same information, can only confuse an already misunderstood subject, even further. I can envision a whole generation of Sommeliers reciting that the upper-slope of Les Caillerets produces heavier, more powerful wine than sections of Caillerets farther down the slope.

It was clear I wasn’t going to find the answers I was looking for in the English language Burgundy books I had access to. Ultimately my questions would become more and more specific, pushing my inquiry of terroir to an elemental level – delving into the construction of the earth and stone, and how it breaks down, and how it might influence the wine we ultimately drink. I still have a tremendous number of questions that will simply go unanswered for quite some time,(7) either due to the lack of research, or that this information is not available in an accessible, English-language format.(8) 

Part One of the article is the result of searching out, reading, and trying to understand small, maybe inconsequential details.  Since I’m putting it out there on the internet, I have made a concerted effort to attempt to get it right. Obviously not a geologist, so despite reading about clay and clay formation dozens of times, from dozens of sources, the complexity of the science makes it easy to over-simplify, to misunderstand it, and definitely, easy to misrepresent. Making making this process more difficult, I could find no articles that (for instance) were specific to the clay and clay formations of Burgundy.(9)

It’s not sexy reading, but I’ve done my best to pull it all together into one place.  If nothing else, I hope this can be a jumping off point for others to research, and expand our cumulative understanding of terroir. 

 

 

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ADDITIONAL NOTES

(1) Even with the top vineyards, publications heavily link the greatness of the wine to the producer, rather than the vineyard. The mantra for the past 30 years has been: producer, producer, producer. While here is a historical reason for this producer-driven focus, I feel the vast improvements in viticulture and winemaking knowledge over the past two decades, coupled with the concurrent global warming, has changed the paradigm, and significantly leveled the playing field between producers. There are now much smaller differentials in quality from the top producers and the lower level producers. I feel that the focus should now return to the vineyards of Burgundy, each with distinct set of characteristics due to its orientation, slope and soils. Nowhere else in the world is this kind of classification so rigorously defined. And because of that, no where else in the world is this kind of ‘study’ possible.

(2) The mapping of Limestone has never really been done before the geologist Francoise Vannier-Petit began her work a number of years ago. She has now mapped Pommard, Gevrey, Marsannay, and Maranges, for the trade associations that have been willing to pay for her services.

(3)  The fact that mud/mudstone (and this is substance is sometimes referred to as shale) is introduced as a term by wikipedia, see table certainly confuses the issue, but they also indicate that this mud is a clay element.

(4) To give credit where credit is due: When I first started doing a overview of our producers, I had summarized this idea, (Pinot liked prefered limestone soils and Chardonnay preferred more clay-rich soils.) My boss, Dr. George Derbalian (with his background in failure analysis) looked and the statement and said, “I don’t know about that.” He asked where I had obtained this information, and when I couldn’t immediately produce the source, he warned: “You have to be very, very, careful about these things. As an importer we have to be completely sure we are right when we say something. I would like to remove this sentence.” I thought he was being over-reactive at the time, and 100% accuracy wasn’t important for the marketing piece I was working on, but later, with much more research under my belt, I would revisit his words with far more respect.

(5) The word marl has a very poorly defined meaning because it is a very old word that was used somewhat indiscriminately. Wikipedia lists marl as a calcium carbonate rich mud with varying amounts of clay and silt in their of the definition. To make matters more confusing Wikipedia’s definition of mud says it has clay in it. Is mud part of marl? Is clay part of mud? Does it really matter?

(6) The quote from the second Master of Wine’s write up of Les Cailleret. I have added the (er) to here to make the passage more clear. “Up at the top of the slope there are outcrops of bare rock. He(re) we find mainly a white marl. This will give the wine weight. Lower down there is more surface soil and it is calcareous, producing a wine of steely elegance. A blend of the two, everyone says, makes the best wine.”

(7) The list of questions I have that don’t have answers seems limitless.  Here are my top questions with no answers at the present: 1) How pervasive is is the fracturing of limestone in the top crus, 2) what kind of limestone is it?  3) does the limestone there fracture and is friable? 4) how much water do these limestones hold, ?  5) how much groundwater is available to the vines? 6) How does the ground water circulate, and 7) how quickly through different types of soil?  8) Where are the faults in the various top climates, 8) are the faults often at the boundaries dividing limestone types? 9)  how deep are the drop-offs (covered by the topsoil) created by the various faultlines?

(8) The University, Lycée Viticole de Beaune is likely to be active in this kind of research, but so far I have not been able to access what might be available, and correct translation from French to English can be problematic if it isn’t done by the author who wrote it, and many times more so if using a translating program (software).

(9) Therefore I’m unable to discuss the types of primary clays, called kaolins which may have formed there in situ, instead focusing on transported clay that has been derived from the erosion of limestone of the vineyards, called Chlorites.

2011 Joseph Roty, Gevrey-Chambertin, “Champs-Chenys”

Champs ChenysChamps-Chenys is one of those vineyards that was given a short shrift when the official INAO classification occurred in 1936. While the vineyard just at its hip (the lower section of Mazoyères-Chambertin*) is classified as Grand Cru, Champs-Chenys was only classified as a village-level wine. At first blush, the two vineyard sections look like a mirrored image of one another. Both vineyards hold the same position and exposition on the hillside. Both vineyards sit above the same Comblanchien limestone. But the difference between Mazoyères (bas) and Champs-Chenys is that Mazoyères sits in richer, sedimentary soils, that over centuries have washed down from a small combe, or ravine, cut into the hill above. This gives the wine from Mazoyères significantly more depth, power, and authority than a wine from Champs-Chenys can, with its limestone-rich marl that is covered with pebbles and galets and sprinkled with pyrite.

Immediately above Champs-Chenys is the Grand Cru “au Charmes” which is more commonly known as Charmes-Chambertin. Charmes has a marl topsoil like Champs-Chenys, but under that lies Premeaux limestone which is more friable than the Comblanchien below Champs-Chenys, so the vine’s roots are better able to penetrate deep into the stone below. Charmes is also warmer with the vineyard being tilted on the hillside toward the sun, and better protected from the wind, being tucked behind the hill. Charmes is well known for its delicate fragrance and rich, seductive fruit, and round smooth mouthfeel.

“This is a wine that is prized by cognoscenti of Burgundy’s finest, yet most under-appreciated vineyards.”

 

Aviary Photo_130556986614926167While all of this side by comparison to Mazoyères and Charmes point to Champs-Chenys being a lesser wine, it is actually very good news for those who realize what a solid vineyard Champs-Chenys actually is…  not to mention what a value it is (in terms of Burgundy) due to its simple village classification.  Additionally, Chez Roty’s parcel of vines is north of 50 years old, and the old plant material, coupled with Philippe Roty‘s considerable winemaking skill, leaves you with a wine that is routinely superb in quality. This is a wine that is prized by cognoscenti of Burgundy’s finest, yet most under-appreciated vineyards.  Roty’s lieu-dits of Champs-Chenys is without a doubt premier cru quality, and it can age effortlessly for decades.

photo 22011 Joseph Roty, Gevrey-Chambertin “Champs-Chenys”

The 2011 is just now coming out of what I felt was a considerable shock after shipping. A full 5 months after arrival, (Roty releases a year later than most other producers,) this Champs-Chenys is displaying this parcel’s distinctive smoky and savage aromas. It is the only cuvee in Roty’s line-up possesses these decidedly meaty smoky traits, indicating it is not the winemaking style rather the plot dictates the wine’s profile.  Although it drank well from the first moment, it really developed beautiful nuance over the course of a day, unfurling notes of roses, blood-like iron aromas underbrush, loam, blackberry and black cherry fruit.

After about an hour, it began showing the exotic, smoky, wild game-tinged aromas I expect to see from Roty’s Champs-Chenys.  The wine is round and quite fresh, and though not as powerful as bigger vintages, this does not lack for concentration. It has good structure, round tannins, and relatively soft acidity, making this a pleasure to drink now. The overall effect is a black-fruited, mid-weight Gevrey that is ripe, but without heaviness, nor is there any sur-maturity. It has excellent fresh fruit character of black cherry fruit that keeps it lively and long. The tannins are fine-grained and the finish that resonates long, and with nice complexity, all of which is highlighted by a deftly handled use of barrique. This a beautiful wine that will keep developing with age, but drinks beautifully now. 90 points when first opened.  92+ points when given time to open up. Very Highly Recommended.  $70

 

*Mazoyères-au Charmes can legally be, and usually, is labeled as Charmes Chambertin. This is because Charmes is a much more recognized name, making it easier to sell. Roughly 10% the wine make from this vineyard is labeled as Mazoyères-Chambertin

2012 Fredreric Esmonin, Gevrey-Chambertin, Clos Prieur

Clos Prieur Bas, with Clos Prieur 1er Cru and Mazis Chambertin directly behind it.

Clos Prieur Bas Vineyard, with Clos Prieur 1er Cru, Mazis Chambertin and the legendary Clos de Beze directly behind it.

Domaine Frederic Esmonin, a firm that produces solid wines from their cellar in Gevrey-Chambertin every year, really made some special Burgundies in 2012. The wines retain Esmonin’s characteristic freshness while gaining a touch more swagger, with modest but noticeable increases in ripeness, concentration, and depth. This is not to say these 2012s are big or heavy wines. They are not, but many crus could use a few years in the cellar.  Having tasted through the entire lineup at our San Francisco Tasting in April, the Clos Prieur was the one wine that was lighter, and quite a bit more aromatic than all of the others.

For me, Clos Prieur was a standout. It had such superb balance, and the aromatics melded seamlessly with its broad red cherry-filled palate while retaining an almost airy weight, all of which struck just the right cord. Whereas the other Gevreys were dark, impressive and somewhat brooding, the Clos Prieur was translucent and open. It is said by some winemakers that these vineyards just south of the village are prone to lightness and delicacy and that if care is not taken can be light and washed out if yields are not kept in check.

The grapes at Esmonin grown lutte-raisonnee. They are said to be destemmed, though I have detected what I believe to be the presence of at least some stems in the cuverie on more than one occasion. The fruit is cold-macerated for a few days, giving them the wines their dark color, before fermenting traditionally. The wines are bottled quite early, giving them a uniquely fresh, almost grapey quality when they are young. Andre Esmonin, Frederic’s father, makes the wine here. I reviewed the delicious, and darker 2012 Esmonin Hautes-Cotes de Nuits earlier this year. See that review here.

Clos Prieur Bas in the center of the map sits in deep marl (loose, earthy deposits that are a mixture of clay and calcium carbonate) over a Combanchien Limestone base.

Clos Prieur Bas in the center of the map sits in deep marl (loose, earthy deposits that are a mixture of clay and calcium carbonate) over a Combanchien Limestone base.

2012 Gevrey-Chambertin Clos Prieur 

This Clos Prieur is just lovely. A translucent ruby-red, this Pinot is all about purity, a quality that not celebrated often enough, and because of that occurs all too rarely in wine. The nose is fresh and buoyant, with cherries, smoke, a touch of thyme, vanilla, and some of Gevrey’s iron-rich meaty notes, along with a light airy quality of fresh roses. Initially, the wine appears lean, but as the palate adjusts, this gives way quickly to a soft round palate that is light and lovely. It’s rose-tinged flavors of cherry, deeper plum, orange peel, vanilla, and cream with a touch of stem, are perfumed and lifted,  just floating on and on. If you look for that animal, it is there, but not so apparent at this stage. I’m assuming this will become more prominent as it ages. This is not a wine and wine style people will accept as being a high scoring wine, but I have to say I really, really enjoyed this. Some have said this to be a bit simple, but I did not find that to be the case. It just wasn’t big and powerful.  Is there a confusion about what complexity is? The future for this wine is that it is destined to change; I think fairly dramatically. I may gain some more weight, and its freshness will certainly replace the more typical Gevrey traits of forest floor and savage animal notes, on it’s very aromatically driven platform. Esmonin’s wines are noted for how effortlessly they age, and this should be no different.  91 points (but I really liked it more than that).

Map produced by geologist Franciose Vannier-Petit for the Gevrey Chambertin Viticultural Society

Map produced by geologist Franciose Vannier-Petit for the Gevrey-Chambertin Viticultural Society

The Vineyard and the Geology

Clos Prieur is the name of two distinctly different vineyards. Despite this, writers have historically referred to them as a single vineyard that is split by classification. The Clos Prieur-Bas section, where this plot is located, sits down-slope, with much deeper marl topsoil, than its sibling. The bottom of Clos Prieur-bas is even more fertile, affected by the alluvial soil that was washed down from the Combe de Lavaux over the centuries.  Beneath the vineyard, virtually impervious to the penetration by the roots of vines, lies the very hard, fine-grained Comblanchien limestone.

On the other hand, the smaller premier cru of Clos Prieur-Haut, which sits atop Clos Prieur-Bas like a mignon, has shallower marl soils and the friable Crinoidal Limestone below. The very bottom of the vineyard is similar soils and Comblanchien to Clos Prieur bas, but it is amazing how closely these ancient vineyard divisions echoed the geology that had not been mapped until very recently. We can thank geologist Francoise Vannier-Petit and the Syndicat Viticole de Gevrey-Chambertin for this in-depth, (literally hundreds of investigative trenches were dug) in order to deliver this ground-breaking research. (I was unable to resist the pun.)

Notably, the premier cru of Clos Prieur sits among a string of premier cru and grand cru vineyards, including Chapelle, Griotte and Charmes-Chambertin, All which follow the same swath of Crinoidal limestone that runs North-South from Gevrey to Morey-St-Denis – and probably doesn’t stop there! This crinoidal limestone flows below the road (the Route de Grand Crus) which is the upper-most boundary of  Clos Prieur-Haut and is no more than 200 yards wide at this point. The Crinoidal limestone widens as it reaches the Clos-de-Beze vineyard, coving half of that cru and half of Chambertin as well. While the road turns away from its path along the limestone toward N74, the line demarcating vineyards continues to follow limestone below.