Formation of Jasperoid and Porphyry

Jasperoid

Porphyry

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1 Formation

1.1 Formation

Jasperoid is a rare and peculiar type of metasomatic alteration of rocks. It is formed by extreme alteration of wall rocks within a shear zone which may occur in sediments, andesites, trachytes and basalts.

Porphyry is formed in two stages: the magma cools slowly deep within the crust or the magma is cools rapidly as it erupts from a volcano, creating small grains that are usually invisible to naked eye.

1.2 Composition

1.2.1 Mineral Content

Clay Minerals, Pyrite, Quartz, Sulfides

Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica

1.2.2 Compound Content

NaCl, CaO, Carbon Dioxide, Magnesium Carbonate, MgO

Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide

1.3 Transformation

1.3.1 Metamorphism

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19% Sedimentary Rocks Rocks have it !

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97% Igneous Rocks Rocks have it !

1.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism

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

1.3.3 Weathering

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78% Sedimentary Rocks Rocks have it !

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99% Igneous Rocks Rocks have it !

1.3.4 Types of Weathering

Not Applicable

Biological Weathering, Chemical Weathering, Not Registered

1.3.5 Erosion

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86% Sedimentary Rocks Rocks have it !

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92% Igneous Rocks Rocks have it !

1.3.6 Types of Erosion

Not Applicable

Chemical Erosion, Coastal Erosion, Glacier Erosion

Jasperoid and Porphyry Formation

Formation of rocks is a long process and hence, Jasperoid and Porphyry 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 Jasperoid and Porphyry, composition of Jasperoid and Porphyry and their transformation.