Formation of Nephelinite and Essexite

Nephelinite

Essexite

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1 Formation

1.1 Formation

Nephelinite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.

Essexite is a type of igneous rock, which is usually dark grey to black plutonic rock. For the formation of essexite, suitable magma with exact composition of K, Ba, Rb, Cs, Sr should be produced.

1.2 Composition

1.2.1 Mineral Content

Clinopyroxene, Nepheline, Plagioclase

Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene

1.2.2 Compound Content

Ca, CaO, Carbon, Cl, MgO

Aluminium Oxide, Ba, Ca, Cs, Potassium, Rb, Sodium, Sr

1.3 Transformation

1.3.1 Metamorphism

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1.3.2 Types of Metamorphism

Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism

1.3.3 Weathering

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1.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering, Chemical Weathering

1.3.5 Erosion

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1.3.6 Types of Erosion

Chemical Erosion, Water Erosion, Wind Erosion

Coastal Erosion, Glacier Erosion, Water Erosion

Nephelinite and Essexite Formation

Formation of rocks is a long process and hence, Nephelinite and Essexite 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 Nephelinite and Essexite , composition of Nephelinite and Essexite and their transformation.