Formation
Basaltic Trachandesite is a fine-grained, hard rock that forms when bits of lava shoot out of volcanoes.
  
Oil Shale forms on the beds of seas and lakes and its formation starts with the organic debris settling and accumulating at the bottom of a lake or sea which are then transformed into rock with the help of high temperature and pressure.
  
Composition
  
  
Mineral Content
Olivine, Plagioclase, Pyroxene
  
Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Ca, Fe, Mg, Silicon Dioxide, Sodium
  
Transformation
  
  
Metamorphism
Yes
  
No
  
Types of Metamorphism
Contact Metamorphism
  
Not Applicable
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
No
  
Yes
  
Types of Erosion
Not Available
  
Chemical Erosion, Sea Erosion, Water Erosion
  
Basaltic Trachyandesite and Oil shale Formation
Formation of rocks is a long process and hence, Basaltic Trachyandesite and Oil shale 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 Basaltic Trachyandesite and Oil shale, composition of Basaltic Trachyandesite and Oil shale and their transformation.