Formation
An argillite is a fine-grained sedimentary rock mainly composed of clay particles which forms from lithified muds which contain variable amounts of silt-sized particles.
  
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
  
Composition
  
  
Mineral Content
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
  
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
  
Compound Content
Iron(III) Oxide, Potassium Oxide, MgO, Silicon Dioxide
  
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
  
Weathering
Yes
  
No
  
Types of Weathering
Biological Weathering
  
Not Applicable
  
Erosion
Yes
  
No
  
Types of Erosion
Chemical Erosion
  
Not Applicable
  
Argillite and Pseudotachylite Formation
Formation of rocks is a long process and hence, Argillite and Pseudotachylite 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 Argillite and Pseudotachylite, composition of Argillite and Pseudotachylite and their transformation.