Chlorite schist 2 : 無料・フリー素材/写真
Chlorite schist 2 / James St. John
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
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| 説明 | Metamorphic rocks result from intense alteration of any previously existing rocks by heat and/or pressure and/or chemical change. This can happen as a result of regional metamorphism (large-scale tectonic events, such as continental collision or subduction), burial metamorphism (super-deep burial), contact metamorphism (by the heat & chemicals from nearby magma or lava), hydrothermal metamorphism (by superheated groundwater), shear metamorphism (in or near a fault zone), or shock metamorphism (by an impact event). Other categories include thermal metamorphism, kinetic metamorphism, and nuclear metamorphism. Many metamorphic rocks have a foliated texture, but some are crystalline or glassy.Schist is an intermediate- to high-grade, foliated metamorphic rock. It is highly variable in appearance, depending on the mineral content, which is a function of the precursor rock and specific temperature-pressure conditions. Garden-variety schists form by metamorphism of phyllites. Schists typically have medium- to large-sized crystals, unlike the microcrystalline nature of slate and phyllite.Schist's foliated texture (= crystals aligned into bands or stripes or layers) is often only seen when specimens are viewed on edge.Chlorite schist is dominated by chlorite, a group of common greenish to greenish-gray metamorphic minerals. Chlorite is a common constituent of greenstone and various types of schist. This example is supposedly composed of prochlorite, a junior synonym for clinochlore (Mg5Al(AlSi3O10)(OH)8, magnesium hydroxy-aluminosilicate).Locality: unrecorded / undisclosed |
| 撮影日 | 2024-12-10 14:31:13 |
| 撮影者 | James St. John |
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