Formation of Anorthosite and Chert

Anorthosite

Chert

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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.

Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.

1.2 Composition

1.2.1 Mineral Content

Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene

Quartz, Silicon

1.2.2 Compound Content

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

Silicon Dioxide

1.3 Transformation

1.3.1 Metamorphism

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1.3.2 Types of Metamorphism

Cataclastic Metamorphism, Contact Metamorphism

Not Applicable

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

Chemical Erosion

Anorthosite and Chert Formation

Formation of rocks is a long process and hence, Anorthosite and Chert 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 Chert, composition of Anorthosite and Chert and their transformation.