Rock Types, Properties and Formation

Rock Types, Properties and Formation

1. Rock Types and Formation

   • Igneous
     • Internal
       • Internal Igneous rock is an Igneous rock that has been created by the magma cooling inside the volcano. They have bigger crystals because the magma cooled down more slowly. Examples of Internal Igneous rocks are granite and diorite.
     • External
       • External Igneous rock is an Igneous rock that has been created by the magma cooling on the outside of the volcano. Magma is outside the volcano it is known as lava. External Igneous rocks have smaller crystals because the lava cooled down more quickly because of the exposure to air. Examples of External Igneous rocks are obsidian and basalt
   • Sedimentary
     • How they are formed
       • Weathering
         • Weathering is the process in which the weather destroys a piece of rock and the grains and dust of the destroyed rock fall down into a river. Lightning, change in temperature, ice and rain are a few of the ways weathering occurs.
       • Transporatation
         • Transportation is the movement of the remaining rubble of the destroyed rock. A river is the most common way that the rubble is moved
       • Deposition
         • Deposition is the depositing of rubble from a fast transportation method, like a river, to a slow moving source, like the sea. Because of the change of speed, the rubble is now dropped instead of carried which starts the formation of the sedimentary rock.
       • Burial
         • Burial is the burying of the deposited rubble. This occurs when more rubble is deposited on the newer rubble which buries the original rubble
       • Compaction
         • Compaction is the connection of the rubble that has been buried. The force and weight of the large pile of rubble forces the rubble to completely crumble to create a massive dust rubble pile.
       • Cementation
         • Cementation is the solidification of the dust rubble pile. The water causes the dust to stick together and eventually the sticky dust stick to each other and become one solid sedimentary rock.
   • Metamorphic
     • How they are formed
       • Heat
         • Metamorphic rock is sedimentary rock that has been changed due to heat
       • Pressure
         • Metamorphic rock is sedimentary rock that has been changed due to pressure

2. Properties

   • Igneous
     • Igneous rock has interlocking grains, crystals and is non porous
   • Sedimentary
     • Sedimentary rock has fossils and layers
   • Metamorphic
     • Metamorphic rock has interlocking grains, crystals, and is non porous. Some metamorphic rocks have fossils in them.