Green Clay

Another type of green clay, bertherine, is formed in the sediments of river deltas. This black-green clay is relatively Fe(II) rich compared to the others. This is thought to be caused by the reducing conditions foimd in the organic-rich sediments characteristic... 

Some green clay minerals occur as ovoids, probably having formed within fecal pellets or casts of forams. They also occur as films or stains on shells, sand grains, and phosphate nodules. They are finmd in highest density in sediments of the outer continental shelves and slopes where waters are shallow (20 to 700 m) and mildly suboxic. Slow sedimentation rates are necessary to prevent burial as green clays form at very slow rates. A notable example are the green muds found on the Blake Plateau. 

Beyond facial creams, facial masks are usually concentrated partide suspensions, and are used to treat and refresh facial skin. The particles are usually either kaoli-nite, Fuller s earth, or illite ( green clay ) or other days. The particles are intended to act as exfoliants and also to adsorb oils from the skin. Other additives span a wide range of materials, including essential oils, vitamins, fruits and vegetables, scents, and pharmaceutical (cosmeceutical) additives, such as salicylic acid when added to treat mild acne. Body clays are like facial masks except that a higher concentration of clay is used in the suspension. 

Up the section, the Old Euxinian deposits are gradually replaced by the sediments of the Uzunlarian Formation (end of the Middle Pleistocene). The boundary between these formations is rather conventional it is traced by the reduction in the number of brackish-water mollusk species and the increase in the abundance of the representatives of euryhaline Mediterranean fauna. In the stratotypical section on the coast of Lake Uzunlarian, this formation is represented by two layers. The lower layer is formed by clayey sands and silts, which, along with brackish-water and fresh-water mollusks and benthic foraminifers, contain numerous shells of euryhaline Mediterranean mollusks (Cerastoderma glaucum, Abra ovata, and others). Above, one finds gray-green clays with interlayers of coquina matter mostly formed by marine Mediterranean species. 

D 4.85 Gray-green clay Quartz, mica-illite, kaolinite Plagioclase... 

Potassic Green Clays (Mica-based Structures)... 

Shallow Ocean Bottom, Marine Green Clays—Glauconite and Berthierine... 

If the geology of the formation of green silicate minerals is relatively well defined, especially at near surface or surface conditions, the question remains how much of the iron is in a reduced oxidation state and how In the case of reduction of iron in surface environments if most of the iron goes to Fe " ", one mineral is formed if only part of it is reduced, another is formed. This is the fundamental geochemical aspect of the genesis of green clay minerals they contain iron in both oxidation states. 

In general, green clays are stable between surface temperatures (2 °C in the deep ocean) and temperatures somewhat above 300 °C. 

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