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Rock Classification - Coggle Diagram
Rock Classification
Igneous Rock
Formed hot from molten rock (magma)
Intrusive
Molten magma cools and crystallizes below the surface
Granodiorite: an example of an intrusive igneous rock where the molten magma has cooled slowly below the surface to grow a network or large interlocking crystals
Extrusive
Where magma reaches the surface, for instance erupting from a volcano
Sedimentary
Made from sediment on the surface of the planet
Clastic sediment: compromised of loose (lithic) fragments of a previous rock
Produced during weathering and erosion of rocks exposed at the surface, mountainous and upland areas
Transported clastic sediment will eventually be dumped, or deposited, to typically form distinct layers known as strata (singular; stratum), or beds.
Can also be formed by directly precitipating the minerals from the water
Limestone is an example of this type of chemical precipitate, and because they typically form in warm, shallow tropical seas, they are often also packed with the debris of fossil shells, plates and spines of the organisms that would have been living there.
Metamorphic
Can be formed from any previous rock type by metamorphosing
This process takesplace below the surface of the planet and is achieved by applying heat/pressure to a rock to change its physical properties or mineralogy until it no longer resembles the original rock
will typically be formed on a regional scale during the intense heating and squeezing which takes place when building mountains, involving high temperature (T) and/or pressure (P).
can also take place on a more localised scale, with high temperature contact metamorphism of cold rock sitting against a molten magma intrusion.