Formation of Anorthosite and Anthracite

Anorthosite

Anthracite

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1 Formation

1.1 Formation

Anorthosite is a phaneritic, intrusive igneous rock which is characterized by a predominance of plagioclase feldspar which is almost 90–100%, and a minimal mafic component.

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.

1.2 Composition

1.2.1 Mineral Content

Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene

Calcite, Clay, Clay Minerals

1.2.2 Compound Content

Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide

Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur

1.3 Transformation

1.3.1 Metamorphism

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1.3.2 Types of Metamorphism

Cataclastic Metamorphism, Contact Metamorphism

Burial Metamorphism, Contact Metamorphism, Regional Metamorphism

1.3.3 Weathering

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1.3.4 Types of Weathering

Biological Weathering

Not Applicable

1.3.5 Erosion

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1.3.6 Types of Erosion

Chemical Erosion, Wind Erosion

Not Applicable

Anorthosite and Anthracite Formation

Formation of rocks is a long process and hence, Anorthosite and Anthracite formation sounds very interesting. According to the formation, all rocks are divided into :Igneous Rocks, Fossil Rocks and Metamorphic Rocks. Igneous rocks form by crystallization of magma or lava. The magma is made up of various components of pre-existing rocks which have been subjected to melting either at subduction zones or within the Earth's mantle. Igneous rocks are generally seen at mid ocean ridges or in intra-plate hotspots. Sedimentary rocks are formed when sediments accumulate gradually. As the sediments are buried they get compacted as more and more material is deposited on top. Eventually the sediments become so dense that they form a rock. Metamorphic rocks are rocks which once existed as igneous or sedimentary rocks but have been subjected to varying degrees of pressure and heat within the Earth's crust. Get to know all about formation of Anorthosite and Anthracite, composition of Anorthosite and Anthracite and their transformation.