Vineyard Soils

The soil composition of vineyards is one of the most important viticultural considerations when planting grape vines. The soil supports the root structure of the vine and influences the drainage levels and amount of minerals and nutrients that the vine is exposed to.

The ideal soil condition for a vine is a layer of thin topsoil and subsoil that sufficiently retains water but also has good drainage so that the roots do not become overly saturated. The ability of the soil to retain heat and/or reflect it back up to the vine is also an important consideration that affects the ripening of the grapes. [Wikipedia]

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Limestone

Limestone are sediments of calcium carbonates from organic matter like fossils and shells.

Famous Limestone Buildings:

Sphinx of Giza
The Great Pyramids
The Parthenon, Greece
The Colosseum, Rome
The Empire State Building, New York

Limestone is a component in many vineyard soils, contributing to the terroir and influencing the characteristics of the wine produced.

Some wine regions are famous for their specific limestone soil, which contribute significantly to the unique characteristics of their wines.

Some of the best wines in world grow in limestone soils: Cham­pagne, Chablis, Sancerre, Saint Emilion.

Limestone is good at absorbing water and releasing it slowly to the vine roots when it is needed.

Even if the vine roots can­not pen­e­trate the hard lay­er of stone, there are deep cracks in the lime­stone. The vine roots will chan­nel down these crackssearch for water and nutri­ents and cre­ate a deeper root systems.

For premium winemaking, limestone soils are considered a true gem due to water holding in dry weather and drainage in wt weather. The soil reflects sunlight, promotes photosynthesis and increases nutrient exchange between soil and vine. Wines tend to be aromatic and elegant.

Limestone is consistently alkaline and is generally planted with grapes of high acidity levels, creating wines of minerality and acidity.

The Paris Basin (Bassin Parisien) is the most famous limestone belt. It runs through the centre of Loire, Burgundy, Champagne, and then to south of England (where the wine industry is beginning to make the most of it).

Grapes:

• Chardonnay
• Pinot Noir
• Sauvignon Blanc

The sedimentary rocks in the Champagne region are 75% limestone.

Saint-Émilion in Bordeaux has a limestone plateau around the town of Saint-Émilion.

Two major types of soil are found in Chablis:

Kimmeridgian limestone is a mix of clay, limestone, and marine fossils.

Portlandian limestone is more limestone and less clay.

The Meursault wine appellation in Bourgogne (Chardonnay, Pinot Blanc, Sauvignon Blanc) has a soil of clay and limestone, with a topsoil of loess and schist.

The Mâconnais wine region in Bourgogne is characterized by limestone hills. The soil is alkaline limestone-based clay with a high content of iron and minerals.

Sussex, Kent and Surrey in England have chalky limestone soils similar to Champagne.

Limestone is the main soil type in the Zinnkoepflé region of Alsace.

Other Regions:

• Jerez (Spain)
• Paso Robles (California, USA)
• Santa Rita Hills (California, USA)
• Robertson Valley (South Africa)

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Different Limestone Types

• Chalk
• Kimmeridgian Limestone
• Marl
• Calcareous Clay
• Dolomitic Limestone
• Albariza Limestone

Each terroir type imparts properties to the soil, affecting water retention, drainage, mineral content, and influence the vine health and the grape characteristics.

The proportion of each type contributes to the a unique terroir of each vineyard.

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Chalk

Chalk is a very porous and soft limestone.

Chalk soils are rich in calcium carbonate and have a high pH. They provide excellent drainage and are often associated with high-quality wines.

Chalk is a porous limestone that vine roots can easily penetrate. Chalky soils works best for grapes with high acidity levels, and can impart minerality to the grapes, contributing to the wine's complexity.

Best known Regions:

• Champagne (France)
• Chenin in Loire (France)

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Kimmeridgian Limestone

Kimmeridgian soil is gray limestone soil originally identified in Kimmeridge in England.

It is composed of clay and fossilized oyster shells.

During the Kimmeridgian age (150 million years ago), warm sea led to an accumulation of carbonate deposits mixing with terrestrial erosion elements, such as clay. This explains the presence of marl oyster fossils in Kimmeridgian soils.

Best known Regions:

• Champagne (France)
• Chablis (Burgundy, France)
• Sancerre (Loire, France)
• Pouilly-Fumé (Loire, France)
• Alsace (France)
• Saint-Emilion (Bordeaux, France)
• Toscana (Italy)
• Puglia (Italy)

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Chablis

In 1904, Professor Georges Chappaz found tiny comma-shaped oyster fossils (Exogyra Virgula) in the subsoil of Chablis (france). Forming banks of limestone, these fossilized shellfish from the Jurassic era are combined with gray marl, a lime rich mudstone. Chappaz classified this as Kimmeridgean soil (from Upper Jurassic era 145 million years ago), observed for the first time in Kimmeridge in England.

The oldest soils in Chablis are Kimmeridgian. They contain the highest degree of mineral-rich clay with marine fossils resulting in high chalky content. The "minerality" of Chablis wines has traditionally been linked to Kimmeridgian soils. Most of Chablis’ vine growers agree that the "mineral" component of their resulting wine is related to the Kimmeridgian soils and its interaction with the Chardonnay grape.

Chablis' Grand Cru vineyards and Premier Cru vineyards are planted on Kimmeridgean soil, while Petit Chablis appellations are mainly grown on Portlandian soils (see below).

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Marl

Marl is a calcareous-clay-based combination of limestone and clay.

Marl adds acidity to wine, and vines planted in Marl soil normally ripen later than in other soil types.

Marl is found in Burgundy (France) especially in the Côte d'Or region, where it provides a fertile base for Pinot Noir and Chardonnay.

Alsace represents a mosaic of vineyard soils from limestone to marl, clay-marl, marl-limestone, granitic, schist, sandstone, loess and alluvial soils.

Marl is the main soil type in the Piedmont wine region of Italy.

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Kimmeridgian Marl

While working in Dorset near the town of Kimmeridge in the south of England, French geologist Alcide d'Obigny, identified a unique layer of dark marl which he named Kimmeridgian. The layer runs from the North Sea to the Paris Basin.

In geologic timescale, Kimmeridgian is in the Late Jurassic Epoch between 157 and 149 million years ago. The Kimmeridgian follows the Oxfordian and precedes the Tithonian.

Kimmeridgian marl is calcareous clay with Kimmeridgian limestone.

The rock comes from the sea, and is rich in fossilized oysters.

Kimmeridgian marl forms the bedrock of the Centre-Loire's wine regions. Locally, the soil is known as terres blanches (white earth).

Terres Blanches is considered a good "late-ripening" terroir. It is made of thick clay layers covered with flat limestone stones, rich in fossils, that have the particularity of whitening while drying in the sun. The terroir gives a strong aromatic concentration, tension and ageing potential to the wines.

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Shale

Shale is a fine-grained, sedimentary rock formed from the compaction of clay, silt, mud and organic matter. It is usually considered equivalent to mudstone.

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Mudstone

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Oxfordian Limestone

Oxfordian limestone from the Jurassic Period, 163 to 155 million years ago, is found in the form of a bed of white stones that are flat as they were shattered by frost. Rain washed the surface earth away, leaving the little stones or caillottes that are so characteristic of Sancerre’s hills visible at the surface. Wines produced from grapes grown in this type of soil are young, fruity and pure.

Best known Regions:

• Sancerre (Loire, France)

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Paris Basin

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Caillottes (Sancerre, Loire)

Caillottes is a soil of fragments of coarse Kimmeridgian limestone.

Cailottes give way in some areas to softer Oxfordian limestone that produces finer fragments known as griottes or very fine fragments called grous.

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Silex

Silex is a flint and sand-based soil type found primarily in the Loire Valley. It is a formed from a mixture of clay, limestone and silica.

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Portlandian Limestone

During the Portlandian age (135 million years ago), the sea level was much higher, terrestrial erosion were rarer and the limestone formed was much harder.

Because of this, Portlandian limestone is not so rich in clay and fossils, and produces wines that are less mineral, but more fruity.

Best known Regions:

• Petit Chablis (Burgundy, France)

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Dolomitic Limestone

Dolomitic Limestone contains both calcium and magnesium carbonate. It is less common, but Northern Italy has soils rich in dolomitic limestone, contributing to the unique mineral profile of its wines. Parts of Burgundy in France also have deposits of dolomitic limestone.

Best known Regions:

• Alto Adige (Italy)
• Burgundy (France)

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Albariza Limestone (Jerez)

Albariza Limestone has similar characteristics to the soil in Chablis and Champagne.

In Jerez, an algae called diatoms, were deposited during the formation of the Guadalquivir river. Later when the seawater receded, the skeletons were deposited, forming the chalky albariza soils which Jerez is known for today.

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Sandstone

Sandstone is a sedimentary rock composed of sand-sized particles that have been formed by pressure.

Best known Regions:

• Alsace (France)
• Chianti (Italy)

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Cambrian Greenstone

Cambrian greenstone soils (unique to the area Heathcote in Australia) are recognised as some the world's oldest soils.

Formed by underground volcanoes 600 million years ago, these ancient soils are highly rich in minerals that form the building blocks for the molecules of colour and flavour in red wine.