Formation of Greywacke and Blueschist

Greywacke

Blueschist

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1 Formation

1.1 Formation

Graywacke rock is a type of sedimentary rock, which is also known as immature sandstone, which is indurated, dark grey and consisting of poorly sorted angular to sub-angular, sand-sized grains.

Blueschist forms due to the metamorphism of basalt and other rocks with similar composition at high pressures and low temperatures and approximately corresponding to a depth of 15 to 30 kilometers and 200 to 500 °C.

1.2 Composition

1.2.1 Mineral Content

Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz

Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz

1.2.2 Compound Content

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

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

Not Applicable

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

Biological Weathering, Chemical Weathering

Mechanical Weathering

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

Coastal Erosion, Sea Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion

Greywacke and Blueschist Formation

Formation of rocks is a long process and hence, Greywacke and Blueschist 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 Greywacke and Blueschist, composition of Greywacke and Blueschist and their transformation.