Formation of Phonolite and Nephelinite

Phonolite

Nephelinite

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1 Formation

1.1 Formation

Phonolite are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.

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.

1.2 Composition

1.2.1 Mineral Content

Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite

Clinopyroxene, Nepheline, Plagioclase

1.2.2 Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Ca, CaO, Carbon, Cl, MgO

1.3 Transformation

1.3.1 Metamorphism

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1.3.2 Types of Metamorphism

Contact Metamorphism

1.3.3 Weathering

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1.3.4 Types of Weathering

Chemical Weathering, Mechanical Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

1.3.5 Erosion

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1.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion

Chemical Erosion, Water Erosion, Wind Erosion

Phonolite and Nephelinite Formation

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