All Soils Flashcards
Acid Soils
Any soil that has a pH of less than 7 (neutral). Typical acidic soils that are acidic due to their parent rock include brown or reddish-brown, sandy loams or sands, volcanic soils, and any igneous or silicate-rich soil. Neutral soils can become acidic from too much humus or acid rain. Acid soils are low in calcium and magnesium, with negligible amounts of soluble salts and reduced phosphorous availability.
Aeolian soil
Sediments deposited by wind (eg, loess). Albariza White-surfaced soil formed by diatomaceous deposits, found in southern Spain.
Alberese
A compact clay and limestone found in the Chianti region. Albero Synonymous with albariza.
Albian
A type of schist found in Maury, Roussillon.
Alkaline soil
Any soil that has a pH of more than 7 (neutral). Typical alkaline soils include chalk and any calcareous soils.
Alluvial deposits
(noun – alluvium) Material that has been transported by river and deposited. Most alluvial soils contain silt, sand, and gravel and are highly fertile.
Aqueous rocks
One of the three basic rock forms (see Rock). Also called sedimentary or stratified.
Arenaceous rocks
Formed by the deposits of coarse-grained particles, usually siliceous, and often decomposed from older rocks (eg, sandstone).
Arène
A coarse, granitic sand ideally suited to the Gamay, arène is found in the Beaujolais region.
Argillaceous soil
This term covers a group of sedimentary soils, commonly clays, shales, mudstones, siltstones, and marls.
Argovian marl
A chalky, clay-like marl found in many parts of the Côte des Beaune.
Arkose
A red, Triassic sandstone consisting of feldspar, quartz, and clay minerals, arkose is often found in the Côtes d’Auvergne and parts of Beaujolais (eg, St-Amour).
Aubuis
Found in the Touraine district of the Loire and highly rated for Chenin Blanc in Vouvray and Montlouis, aubuis is a stony mix of permeable, fertile, calcareous clays that are said to be well suited to white grape varieties.
Barro
A similar soil to albariza but brown in colour, sandier, and with less diatomaceous content. While Palomino grapes are grown on albariza soil, barro is reserved for Pedro Ximénez grapes.
Basalt material
This accounts for as much as 90 per cent of all lava-based volcanic rocks. It contains various minerals, is rich in lime and soda, but not quartz, the most abundant of all minerals, and it is poor in potash.
Bastard soil
A Bordelais name for medium-heavy, sandy-clay soil of variable fertility.
Bauxite
As well as being a valuable ore mined for aluminium production, bauxite is found in limestone soils of Coteaux de Baux-de-Provence.
Block-like soil
Referring to the soil structure, “block-like” indicates an angular or slanting arrangement of soil particles.
Boulbènes
A Bordelais name for a very fine siliceous soil that is easily compressed and hard to work. This “beaten” earth covers part of the Entre-Deux-Mers plateau.
Boulder See
Particle size
Calcareous clay
Argillaceous soil with carbonate of lime content that neutralizes the clay’s intrinsic acidity. Its low temperature also delays ripening, so wines produced on this type of soil tend to be more acidic.
Calcareous soil
Any soil, or mixture of soils, with an accumulation of calcium and magnesium carbonates. Essentially alkaline, it promotes the production of acidity in grapes, although the pH of each soil will vary according to its level of “active” lime. Calcareous soils are cool, with good water retention. With the exception of calcareous clays (see above), they allow the vine’s root system to penetrate deeply and provide excellent drainage. Carbonaceous soil Soil that is derived from rotting vegetation under anaerobic conditions. The most common carbonaceous soils are peat, lignite, coal, and anthracite.
Chalk
A type of limestone, chalk is a soft, cool, porous, brilliant-white, sedimentary, alkaline rock that encourages grapes with a relatively high acidity level. It also allows the vine’s roots to penetrate and provides excellent drainage, while at the same time retaining sufficient moisture for nourishment. One of the few finer geological points that should be adhered to is that which distinguishes chalk from the numerous hard limestone rocks that do not possess the same physical properties.
Clay
A fine-grained argillaceous compound with malleable, plastic characteristics and excellent water-retention properties. It is, however, cold, acid, offers poor drainage, and, because of its cohesive quality, is hard to work. An excess of clay can stifle the vine’s root system, but a proportion of small clay particles mixed with other soils can be advantageous.
Clayey-loam
A very fertile version of loam, but heavy to work under wet conditions, with a tendency to become waterlogged.
Cobble See
Particle size Colluvial deposits (noun – colluvium) Weathered material transported by gravity or hill-wash.
Crasse de fer
Iron-rich hard-pan found in the Libournais area of France. Also called machefer.
Crystalline
May be either igneous (eg, granite) or metamorphic.
Dolomite
A calcium-magnesium carbonate rock. Many limestones contain dolomite.
Entroques
Type of hard limestone found in Burgundy (eg, Montagny).
Feldspar or Felspar
One of the most common minerals, feldspar is a white- or rose-coloured silicate of either potassium-aluminium or sodium-calcium-aluminium and is present in a number of rocks, including granite and basalt.
Ferruginous clay
Iron-rich clay.
Flint
A siliceous stone that stores and reflects heat and is often associated with a certain “gun-flint” smell that sometimes occurs in wines, although this is not actually proven and may simply be the taster’s auto-suggestion.
Gabbro
A dark, coarse-grained igneous rock found in Muscadet.
Galestro
Rocky, schistous clay soil commonly found in most of Tuscany’s best vineyards.
Glacial moraine
A gritty scree that has been deposited by glacial action.
Gore
A pinkish, decomposed, granitic arenaceous soil found in Beaujoalais, St Joseph, and Côtes Roannaise.
Gneiss
A coarse-grained form of granite.
Granite
A hard, mineral-rich rock that warms quickly and retains its heat. Granite contains 40 to 60 per cent quartz and 30 to 40 per cent potassium feldspar, plus mica or hornblende, and various other minerals. It has a high pH that reduces wine acidity. Thus, in Beaujolais, it is the best soil for the acidic Gamay grape. It is important to note that a soil formed from granite is a mixture of sand (partly derived from a disintegration of quartz and partly from the decomposition of feldspar with either mica or hornblende), clay, and various carbonates or silicates derived from the weathering of feldspar, mica, or hornblende.
Gravel
A wide-ranging term that covers siliceous pebble of various sizes that are loose, granular, airy, and afford excellent drainage. Infertile, it encourages the vine to send its roots down deep in search of nutrients. Gravel beds above limestone subsoils produce wines with markedly more acidity than those above clay.
Greensand
A dark greenish coloured, glauconite-rich sand of Cretaceous origin found in some vineyards in southeast England. Greensand is used as a water softener, which is ironic considering that it is found over chalk subsoil, known for its hard water.
Greywacke
Argillaceous rocks that could have been formed as recently as a few thousand years ago by rivers depositing mudstone, quartz, and feldspar. Commonly found in Germany, South Africa, and New Zealand.
