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.

 

 

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Understanding the Terroir of Burgundy Part 1.3: The Question of Amoureuses and Comblanchien

 by Dean Alexander

And then there is the issue of Amoureuses.  Early last year, Decanter magazine published an article profiling Francoise Vannier-Petit, in which the geologist noted that the soils of Amoureuses have “only 10cm–15cm of soil above the subsoil”. It was in the context of another subject, so nothing was mentioned about the stone below, but given this lack of topsoil over Amoureuses, I would not expect a hard stone like Comblanchien to lie below just below the surface. This is a stone prized by architects and designers for is grains so fine that it is virtually impervious to water, for its immense strength, and its high levels of elasticity, all which are due to its nearly pure 99% calcium carbonate content. In other words it is very resistant to fracturing. But that is just what two of the premier experts on Burgundy, Clive Coates and Remington Norman, have written: Comblanchien lies below Amoureuses.

amoureuses topography

Amoureuses hangs off of Le Musigny like a broken appendage, with topography unlike any other vineyard in Burgundy.

I first became aware of this reported bedding of Amoureuses, when Neal Martin, in his introduction to reviewing the wines of the vineyard, mentioned that the vines were planted to a bedrock of Comblanchien. It seemed that this information could not to possibly be true. This stone’s ability to resist fracturing was proved again and again in quarries across the Côte. I emailed The Wine Advocate, suggesting this information may not be correct, and if they had a geological source for that information. I was beyond curious. Neal Martin kindly responded, citing Clive Coates’ book, “My Favorite Burgundies”.  This would come up again once I finished Part 1.2 of this series. In the comments section, a very knowledgeable reader, Victor discusses that both Coates and Remington Norman claims Comblanchien lies beneath Amoureuses.

So it was time to search out Coates’ now oft-mentioned passage. It follows.

The soil here is similar but shallower than the lower sections of Musigny above. There is more rock and more limestone on the section closest to the overhang, and there is some sand. But overall it is very gravelly, mixed with limestone debris, the limestone being less active than elsewhere in the commune, directly over the mother rock, Comblanchien in origin.  Clive Coates, My Favorite Burgundies

In considering what he wrote, these are my takeaways: The limestone debris he writes of, typically would have slid downslope from above, onto Amoureuses. However, if the stone was significantly fractured, and with 10 to 15cm of soil, at some of this colluvium could have been developed in situ. It is very likely that centuries of farming would have churned up stone below to combine with debris accumulated from other locations.

When he talks of  the limestone being less active, he is referring to the fact that the gravel and stone of the vineyard is tightly pored, causing it to resist chemical weathering. This would be consistent with a very tightly grained, limestone with a very high calcium carbonate content. This is certainly a clue pointing toward Premeaux or Comblanchien limestone as the base for the colluvium. It means the calcium carbonate is not as active in becoming solvent due to carbonization, and very little clay is being formed at the site. It may also mean that the soil has a lower pH than other vineyards in Burgundy. This is all covered in-depth in part 2.1.

The primary limestones of the Cote de Nuits.

Four of the several limestones of Marsannay and the Côte de Nuits. photo: Organisme de Défense et de Gestion de l’AOC Marsannay

With all that description, however, he never mentions any fracturing to the “mother rock,” and at least to me, this is the key the issue at hand. If the stone was indeed Comblanchien, then it would have to be significantly fractured for vines to grow there. Given that in all of Gevrey, where there is significant Comblanchien, the stone is never present where the soil was shallow.

Further bolstering my doubt, was that stone had been quarried only a matter of feet from the vines Amoureuses, where the premier cru vineyard of Vougeot “Les Petit Vougeot” is located today. The stone cut from Les Petit Vougeot site was used for the construction of  Abbaye de Cîteaux, which after the revolution in 1790, was seized from the church and renamed the Chateau de Clos Vougeot. Certainly, the Abbey wasn’t built out of fractured and crumbling stone.  If the limestone in Amoureuses is, in fact, a hard stone, much less the hardest stone, the base rock could not just have a few fractures. It would have to be shattered. I was virtually sure the stone had been misidentified.

however…

However, a very visible fault cuts through the vineyard that seems to end abruptly at the quarry site. The lower section of the vineyard having been torn away, and down from the upper portion. This required extensional stress, the kind which is most damaging to stone, literally pulling it end from end. From that extensional stress, we can expect deformation and fracturing throughout the stone structure, on either side of the fault.
We also know that the longer the elastic range of stone (and Comblanchien is very elastic due to its 99% calcium carbonate content), the shorter the ductile deformation range. In other words, like a rubber band, it will stretch significantly before it snaps; but when it does, it will snap suddenly.

Topographically speaking, there are no other vineyard locations in the Côte de Nuits-like this stair-stepped vineyard, save Haut Doix which is joined at its hip. They are remarkably unique vineyards for the area. Certainly, something geologically special had happened here.

So with no more information, the question of Amoureuses remained open. But perhaps I would be able to answer the question whether it is possible to plant vines in shallow soil above Comblanchien, or in other words, remove my doubt. I would begin a look for examples of Comblanchien at shallow depth in other vineyards…and I really wanted to know what shattered Comblanchien might look like. I would find answers to both.

Enter parallel evidence.

Marsannay En la Montagne

Marsannay cru of La Montagne: Against the base of the hill sits a steep face of 12% slope. Here the soil is very shallow, with compact soils, and notably geologist Vannier-Petit has identified the stone below as Comblanchien. Interestingly, Vannier-Petit doesn't show any faulting at its base, which I would have expected. I makes me wonder what the reason for this for transition of stone type, and what caused the dramatic change in elevation? Folding would explain the elevation gain, but not the change in limestone. As always, there are more questions with no answers.

After an initial flat section of vineyard, a hillside of Comblanchien stone rises in the middle of the La Montagne vineyard. The slick PR brochure claims the hill to be a 12% grade, but it appears to be much less. The soil on the base is claimed in the brochure to be shallow and compact, two characteristics I would expect on a steeper slope. Vannier-Petit’s map shows a major fault just to its north-east. I wonder what the reason for this for transition bedding, without faulting, and what caused the change in elevation? Folding would explain the elevation gain, but not the change in limestone. As always, there are more questions with no answers. map source: Organisme de Défense et de Gestion de l’AOC Marsannay

Combe du La Montagne sits near the mouth of the Combe du Pré, a large ravine or valley, just north, above this photo. Interestingly, but not unusual, the map shows vineyard plots that don't exist. According to the map, there should be a small sliver of a vineyard between the two vineyards on the upper right of the photo, but there is not one that I can detect from satellite images. It is solid forest in that location.

The vineyard En la Montagne sits near the mouth of the Combe du Pré, a large ravine or valley, just north, above this photo. Interestingly, but not unusual, the map shows vineyard plots that don’t seem to exist. According to the map, there should be a small sliver of a vineyard between the two vineyards on the upper right of the photo, but I can detect none from satellite images of the region. There is nothing but continuous forest in that location.

Geologist, Francoise Vannier-Petit’s work in Marsannay was commissioned by the regional trade organization, the Organisme de Défense et de Gestion de l’AOC Marsannay, and the results were released to the public in March of 2012. This information was assembled for a public relations brochure, developed to support the organization’s application for gaining premier cru status for various top vineyards within Marsannay.

I had discovered the publication (which is entirely in French) in June of 2014 but had really only inspected the sections germane to our producer of Marsannay wines, Domaine Joseph Roty. In truth I had completely forgotten I had this information in my possession, until I started to wonder if Comblanchien could be found in Marsannay, an area Vannier-Petit had surveyed. Apparently, there is an English version available but have not been able to find it.

Regarding Marsannay in general, she brings up some really interesting observations I had never seen in regards to Burgundy. This is relevant because many authors have mentioned that Marsannay and Gevrey are very similar in terms of soil types.

“The horizontal layers of limestone and marl are fractured; they form broad stairs of several hundred meters, collapsing from West to East. The intense fracturing of the clay-limestone alternations composed a geological mosaic on which is superimposed on the plot lace localities of the appellation. The expression of the multifaceted local proves through this great geological diversity.”

Clearly, the google translation is not perfect, despite this, it is of considerable interest that she mentions that the “clay-limestone alterations” are “intensely fractured”.  Within this paragraph are several illuminating concepts that I have never read before regarding Burgundy, and are very likely a significant factor understanding soil production for the Côte. 

More than just limestone

Marlstone 

sedimentary stone flowchart

sedimentary stone flowchart. Click to enlarge

The first mention is of fractured marl (small limestone particles mixed with clay), indicating this was marl which over long periods had been indurated (hardened) by geologic pressures. Marlstone was a favorite building material of the Romans, who prized it for its workability, but it is more prone to fracturing and chemical weathering than limestone. This is likely due to its relative porosity, as well as its weaker chemical bonding of the mixed materials that make it up.

Claystone

very low on the slope This limestone is found at a turn in the road, very low on the slope, just before the road tilts upward. sits this stone which is heavily colored by the rust from the soil. This certainly looks like a fault line, and the hillside above is steep, suggesting the bedding plane is tilted. The stone is holding together, but just barely, with heavy horizontal fracturing evident by the long striations. Certainly the root systems of the trees and bushes are adding its destruction.

This stone is found before D108s first hairpin, very low on the slope. The stone is holding together, but just barely, with heavy horizontal fracturing evident by the long striations. Certainly, the root systems of the trees and bushes are aiding its destruction. photo: Googlemaps. click to enlarge

Also mentioned in the next sentence is layers of clay which also had been indurated into claystone. Claystone, which is harder than steel, can fracture due to hydraulic expansion as it gains moisture. Further frost wedging and can shatter into many small, hard fragments which can be dispersing throughout the soil. If it is chemically weathered, it can regain its plasticity, and return to its clay form. Much more about the formation clay and its close relationship to limestone in Part 2.1.

Mudstone and Shale

Now depending on the amount of silt (particles of feldspar and quartz that are larger than the particles of clay) mixed into the clay, this hybrid material can be termed as mudstone. Mudstone which is made up of many fine layers is considered to be laminated, and if it can be split into many layers, it is considered to have fissile. And just like that, we are now talking about shale. The relationship between these materials is so close, that through mechanical and chemical weathering, the shift forms from one to anther, and back.

The brochure and the search for fractured Comblanchien

While a couple of other vineyards had notable amounts of Comblanchien low on the slopes where there would be deeper soils, these were not of interest. Only the only the upper slopes where the soil would be shallow like Amoureuses were relevant. One vineyard, in particular, fits the criteria, En la Montagne.

Marsannay en la Montagne. Map Vannier Petit & Emmanuel Chevigny

Marsannay en la Montagne. Map Vannier Petit & Emmanuel Chevigny

En la Montagne is in the northern most section of Marsannay la Côte, the largest of the three villages that are entitled to use the name Marsannay.  The vineyard sits just below the mouth of an enormous ravine, the Combe du Pré. Several of these ravines cut through the significant hills above Marsannay, and are have a significant impact on the wines of the region, having spilled wide areas of alluvial soils across swaths of vineyard land, and allowing air to travel easily east-west through their openings, cooling the region. The hillside has a pair of significant faults which water likely exploited, cutting through the hillside, creating the Combe du Pré via thousands, if not hundreds of thousands of years of constant erosion.

Regarding En La Montagne {from the brochure}:

Located at the top of the hillside vineyard between Chenôve and Marsannay-la-Côte, the place called “In this Mountain” (En la Montagne) a large topographic variation, from 292 to 354 meters above sea level, with an average altitude of 315 meters. The slope is small foot hill ( 3%) and high hillside high (12%) , with an average value of 5%for the locality. The climate is south facing. 

La Montagne is based exclusively on limestone bedrock. The limestone Prémeaux, white Oolite and especially the Comblanchien provide abundant clear stones and a very thin soil.

Clear stones, I can only assume means thant they are free from impurities, and are nearly pure in calcium carbonate.

 

Upper slopes of La Montagne. The slope is more gentle than the name or brochure suggests. You can see D108 winding up the hill in the background.

Upper slopes of La Montagne. The slope is more gentle than the name suggests. You can see D108 winding up the hill in the background.

The vineyard itself is quite small, with a flat section at the bottom, and a relatively short rise before the tree line. I would not expect exceptionally shallow soils due to its relatively gentle rise of 3%. This rise is where the Comblanchien lies. The slope rises more steeply once in the trees. The small plots above, which also have Comblanchien as bedrock are not significantly steep either, however. The vineyard section in the photo below looks to be around 4% to 5% near the top, but the bottom it looks to be a bit steeper.

An upper plot of la Montagne which is over Comblanchien

An upper plot of la Montagne which is over Comblanchien. This looks to be 7 to 8% grade near the bottom, and more like 4 to 5% toward the top. Ironically, this road leads to a small public drop off point for garbage.

While it there are no direct correlation that made from en la Montagne to les Amoureuses, as their circumstances, soil and locations are very different, the existence of Comblanchien below this vineyard and the highly fractured Comblanchien in the hills above, certainly gives evidence that Comblanchien is no more immune from severe fracturing than any other limestone, given the right circumstances.

Yes. Amoureuses could very well be fractured Comblanchien. Additionally, the photos below show that while significant fracturing can occur in one location, the stone, just a few yards away, may remain intact.

Comblanchien?

What does fractured limestone look like below the vineyards Burgundy? Here is the answer. This taken via googlemaps, on the lower slopes of D108.  Photo: googlemaps  click to enlarge

 

This map is difficult to determine where the road is as the line indicating it stops before it reaches the section of D108 where these photos are taken. The road clearly does cross at least one fault line (the red lines on the map) Map Vannier-Petit and Françoise Dumas

 

La Montagne to the right and the road up the combe to the left.

La Montagne to the right and the road up the combe to the left.

 

lower on the slope

This is also shot on lower on the slope, just after the first curve going up the hill. Although the Terre rouge or soil containing iron-oxide which stains the stone, it appears these may be two separate beddings. The white stone on the bottom center appears to be Comblanchien, while the yellow stone to its right may be Premeaux or other another limestone. This would match the change in Vannier-Petit’s map, but determining the location impossible.  photo: googlemaps  click to enlarge

Higher on the slope

Higher on the slope, this white limestone is likely fractured Comblanchien. While on the incomplete section of the map, Comblanchien is indicated this far up on the hillside. Photo: googlemaps  click to enlarge

limestone  photos: googlemaps  click to enlarge

unfractured limestone

Unfractured limestone low on the slope of the first turn. Why didn’t this stone on the left side of the photo fracture, when all else did? The right side of the photo shows some fracturing.  photo:googlemaps  click to enlarge

 


Author’s Note: Vannier-Petit is credited at the end of the publication as being responsible for the conception and information in the brochure, so I have accepted the words within it as if she were the author, which is likely not the case.

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.