Formation
Anthracite forms from the accumulation of plant debris in a swamp environment. When plant debris dies and falls into the swamp, the standing water of the swamp protects it from decay.
Eclogite forms from high-pressure metamorphism of mafic igneous rocks mainly, basalt or gabbro as it plunges into the mantle in a subduction zone.
Composition
Mineral Content
Calcite, Clay, Clay Minerals
Amphibole, Coesite, Corundum, Dolomite, Garnet, Kyanite, Lawsonite, Paragonite, Phengite, Pyroxene, Quartz, Rutile, Zoisite
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, Magnesium Carbonate, MgO, Sodium Oxide, Potassium, Sodium
Transformation
Metamorphism
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Types of Metamorphism
Burial Metamorphism, Contact Metamorphism, Regional Metamorphism
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Weathering
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Types of Weathering
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Mechanical Weathering
Erosion
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Types of Erosion
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Chemical Erosion, Sea Erosion