Rocks

• Are formed when molten material cools and solidifies?

  Igneous Rocks
• When igneous rocks form below the surface of the Earth, they are called intrusive igneous rocks or plutonic rocks. When they form on the surface, they are called extrusive igneous or volcanic rocks.
• The composition of magma depends on the amount of silica (SiO2), which affects its viscosity, and temperature. 
• Very rare type of extrusive igneous rock?

  Komatiite
• Other more common types of extrusive rocks are obsidian (formed when lava rapidly cools; also known as volcanic glass), bombs (rounded solidified lava fragments), blocks (angular solidified lava fragments), and volcanic ash.
• What are Clastic sedimentary rocks?

  A) Breccia

  B) Conglomerate

  C) Sandstone

  D) Mudstone

  E) Shale

  
• Are formed when water evaporates, leaving behind dissolved minerals. Common examples include halite or rock salt, gypsum, flint, chert, travertine, umber, and limestone rocks.


  Chemical sedimentary rocks
• Are sediments come from pre-existing rocks. Classified based on the characteristics of their clasts, such as size, angularity/roundedness, and sorting.


  Clastic sedimentary rocks
• Are formed from loose material called sediments that have been eroded in weathering and then buried and compacted in a process called diagenesis


  Sedimentary rocks
• Are composed of the remains of living things (shells, bones, plant fragments, etc.). Common examples include some fossiliferous limestone (contains fossils), chalk (composed of very tiny marine organisms called coccolithophores and foraminifera), coquina (composed of >2 mm shell fragments and grains), and coal (altered rock from remains of plant life).


  Biochemical or organic sedimentary rocks
• When a rock is subjected to certain chemical (addition or removal of chemicals) or physical (change in temperature or pressure) processes that alter its chemical composition, mineralogy, and/or texture, a metamorphic rock is formed.
• The original rock or “parent rock” that was altered is called a protolith. Metamorphic rocks are divided into two types based on their texture. 
• Foliation in rock is the result of deformation; the more foliated a rock, the higher the grade of metamorphism. What are the Foliation rock names?

  A) Shale

  B) Phyllite

  C) Schist

  D) Gneiss

  
• Nonfoliated rocks usually develop in environments where deformation is minimal and other factors, such as chemically-active fluids, play a larger part in altering the rock. What are Nonfoliated rock names?

  A) Marble

  B) Hornfels

  C) Quartzite

  D) Metapelite

  
• Illustration of Rock cycle.

  A) Weathering

  B) Crystallization

  C) Metaphorism

  D) Lithification

  E) Deposition

  F) Transportation

  G) Consolidation

  H) Uplift and exposure

  I) Sedimentary

  J) Methamorphic

  K) Extrusive

  L) Intrusive