Marl (Clay + Limestone: Champagne, Burgundy, Alsace)

Decanter's Tim Hall uses clay and limestone together to describe marl, writing of a "clay-limestone (marl) soil blend" in Champagne's Côte des Bar, and calls the region's Kimmeridgian ground "a clay-chalk marl like in Chablis and Sancerre". The Bourgogne wines site describes the gray marl in the Chablis subsoil as "a lime rich mudstone". vinsalsace.com uses the word for thick clay deposits: its marl-calcareous terroirs "are composed of thick clay deposits (marl) and calcareous pebbles". champagne.fr names marl as one of the three rock types, with chalk and limestone proper, that make up Champagne's limestone outcrops.

• Decanter (Tim Hall, 2022): marl as a clay-limestone blend in the Côte des Bar
• Bourgogne wines site: Chablis gray marl is a lime rich mudstone
• vinsalsace.com: marl as thick clay deposits in Alsace's marl-calcareous terroirs
• champagne.fr: marl sits alongside chalk and limestone proper in Champagne's sedimentary outcrops

The marls of these wine regions are sedimentary. champagne.fr says that 90 million years ago oceans covered every surface of land and sediments settled on the seabed, piling up to as much as 200 metres, before the Paris Basin gradually sank and various types of rock surfaced in successive layers; today, it says, Champagne's sedimentary outcrops are 75% limestone, composed of chalk, marl and limestone proper. In Chablis, on the edges of the Paris basin, the Bourgogne wines site describes fossilised Jurassic shellfish combined with gray marl in the soil Chappaz classified as Kimmeridgean, around 145 million years old. In Alsace, vinsalsace.com says that 150 million years ago the sea rolled over what is now the Rhine Rift Valley, and sedimentary rocks such as sandstone, limestone and marl settled atop the granite platform. On the Côte de Nuits and Côte de Beaune, the Bourgogne wines site describes Jurassic strata laid bare by a fault rupture during the Tertiary era, leaving subsoils that are clay-limestone in nature.

• Champagne: sediments laid down on a seabed 90 million years ago, surfacing in layers as the Paris Basin sank (champagne.fr)
• Chablis: gray marl combined with Jurassic fossil limestone banks in the Kimmeridgean stratum, around 145 million years old (Bourgogne wines site)
• Alsace: sandstone, limestone and marl settled 150 million years ago when the sea covered today's Rhine Rift Valley (vinsalsace.com)
• Alsace today: the Rhine alluvial plain is described as marl and alluvial (vinsalsace.com)

The sources tie marl to weight, roundness and acidity. vinsalsace.com says the marl influence in Alsace's marl-calcareous terroirs is sustained by a long and complex acidity, that the wines are generous and long in their youth, and that the more limestone is present, the finer the wines become. In the sandstone variant, it says, marl provides weight to the wine whereas sandstone lightens it up. In the Côte des Bar, Tim Hall writes in Decanter that the clay-limestone (marl) soil blend tends to make rounder, fuller styles of Champagne than the stricter north. In Burgundy, the Bourgogne wines site says the Chardonnay grape thrives on limestone and marls with a lot of clay, resulting in dry white wines such as Puligny-Montrachet, Meursault and Corton-Charlemagne.

• Alsace marl-calcareous terroirs: long, complex acidity; the more limestone, the finer the wines (vinsalsace.com)
• Alsace marl-sandstone terroirs: marl provides weight, sandstone lightens (vinsalsace.com)
• Côte des Bar Champagne: rounder, fuller styles than the stricter north (Decanter, Tim Hall)
• Burgundy Chardonnay: thrives on limestone and marls with a lot of clay (Bourgogne wines site)

In Champagne, champagne.fr says the choice of grape variety depends on whether the soil is marl, chalk or hard limestone: Chardonnay is mainly grown in the Côte des Blancs and Côte de Sézanne, Pinot Noir in the Montagne de Reims, the eastern part of the Marne Valley and the Côte des Bar, and Meunier in the western part of the Marne Valley. In Burgundy, the Nuits-Saint-Georges appellation, which includes the commune of Premeaux-Prissey, has deep marly-limestone soils in its southern sector, while soils in the northern sector derive from pebbly alluvium; on the hill of Corton, the Corton-Charlemagne Grand Cru vineyard has marly, clay-rich soil; and farther south, more marly soils emerge in the Côte Chalonnaise and the Couchois. In Alsace, vinsalsace.com lists marl-calcareous, marl-sandstone and marl-limestone-sandstone terroirs, and describes the Rhine alluvial plain as marl and alluvial. In Rioja, riojawine.com describes Rioja Alta's soils as a mixture of clay-limestone, clay-ferrous and alluvial, and says soils in Rioja Alavesa are 95% clay-limestone; these pages use the term clay-limestone rather than marl.

• Champagne: marl, chalk or hard limestone guides the choice between Chardonnay, Pinot Noir and Meunier (champagne.fr)
• Nuits-Saint-Georges: deep marly-limestone soils in the southern sector; AOC dating from September 1936, with 41 Premiers Crus Climats (Bourgogne wines site, read 2026)
• Corton-Charlemagne Grand Cru: marly, clay-rich soil; granted AOC Grand Cru in 1937 (Bourgogne wines site)
• Alsace: marl-calcareous, marl-sandstone and marl-limestone-sandstone terroirs (vinsalsace.com)
• Rioja: clay-limestone soils in Rioja Alta and Rioja Alavesa (riojawine.com, read 2026)

The sources describe marl's role alongside its neighbours in the soil. champagne.fr says Champagne's subsoil of chalk, marl and limestone proper is porous, allowing good drainage, so vine roots stay dry, which helps to increase grape quality. Its FAQ separates the roles: marl retains just the right amount of moisture and heat from the sun, heavy clay is able to hold water and acts as a nutrient reserve, and chalk acts as a water reservoir and temperature regulator. vinsalsace.com says the sub-Vosges hills, with clay, limestone and sandstone soils, are very fertile and boast great water-storing capacity, with the limestone and sandstone lightening up the soil where the marl brings its weight. In the Côte de Nuits and Côte de Beaune, the Bourgogne wines site says a vine's roots can reach down as far as 10 yards into the soil.

• Drainage: Champagne's porous subsoil of chalk, marl and limestone proper (champagne.fr)
• Moisture and warmth: marl retains just the right amount of moisture and heat from the sun (champagne.fr)
• Water and nutrients: heavy clay holds water and acts as a nutrient reserve (champagne.fr)
• Weight: marl brings weight to sub-Vosges soils, lightened by limestone and sandstone (vinsalsace.com)

Primary sources: https://www.champagne.fr/en/about-champagne/the-champagne-terroir/champagne-and-its-soil, https://www.champagne.fr/en/champagne-frequently-asked-questions?nid=608, https://www.bourgogne-wines.com/wine-and-terroir/bourgogne-and-its-appellations/nuits-saint-georges,2458,9253.html?args=Y29tcF9pZD0yMjc4JmFjdGlvbj12aWV3RmljaGUmaWQ9MzYxJnw%3D, https://www.bourgogne-wines.com/wine-and-terroir/our-natural-assets/geology/the-collapse-of-the-bressan-rift/the-cote-de-nuits-cote-de-beaune-and-cote-chalonnaise-created-from-a-major-geological-upheaval,2481,9403.html, https://www.bourgogne-wines.com/wine-and-terroir/our-natural-assets/geology/the-heritage-of-the-paris-basin/chablis-the-grand-auxerrois-and-the-cha-tillonnais-on-the-edges-of-the-paris-basin,2480,9402.html, https://www.vinsalsace.com/en/terroirs/remarkable-geology/, https://riojawine.com/en-us/production-areas/rioja-alta/, https://riojawine.com/en-gb/production-areas/rioja-alavesa/. Secondary: https://www.decanter.com/premium/regional-profile-champagnes-cote-des-bar-489173/. Last verified 2026-09-28