Formation of Anorthosite and Arkose

Anorthosite

Arkose

Add ⊕

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.

Arkose rock forms from the weathering of feldspar-rich igneous or metamorphic rock, most commonly granitic rocks, which are primarily composed of quartz and feldspar.

1.2 Composition

1.2.1 Mineral Content

Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene

Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz

1.2.2 Compound Content

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

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

1.3 Transformation

1.3.1 Metamorphism

✔ ✘

97% Igneous Rocks Rocks have it !

✔ ✘

19% Sedimentary Rocks Rocks have it !

1.3.2 Types of Metamorphism

Cataclastic Metamorphism, Contact Metamorphism

Not Applicable

1.3.3 Weathering

✔ ✘

99% Igneous Rocks Rocks have it !

✔ ✘

78% Sedimentary Rocks Rocks have it !

1.3.4 Types of Weathering

Biological Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

1.3.5 Erosion

✔ ✘

92% Igneous Rocks Rocks have it !

✔ ✘

86% Sedimentary Rocks Rocks have it !

1.3.6 Types of Erosion

Chemical Erosion, Wind Erosion

Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion

Anorthosite and Arkose Formation

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