KINDS OF ROCKS By:Janine Luberas, John Edmon Bartolome,Kimberly Sison and Joyce Abner
1.Igneous rocks are one of thethree major rock types and arebasically rocks that solidifiedfrom magma. Magma is theterm for liquid or melted rockand is usually quite hot. After all,the term igneous comes fromthe Latin word for "of fire". Mostpeople have seen pictures orvideo of magma that flows out ofa volcano. When magma flowsonto the surface of the Earth it iscalled lava. When the lava coolsand forms a rock, that rock isan igneous rock.
Sedimentary rock are types of rock that are formed by the deposition of material at the Earths surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic par ticles (detritus) to settle and accumulate or minerals to precipitate from a solution. Particles that form a sedimentary rock by accumulating are called sediment.
Metamorphic rock is the transformation ofan existing rock type, the protolith, in aprocess called metamorphism, whichmeans "change in form". The protolithissubjected to heat and pressure(temperatures greater than 150 to 200 °Cand pressures of 1500 bars) causingprofound physical and/or chemical change.The protolith may be sedimentaryrock, igneous rock or another oldermetamorphic rock. Metamorphic rocksmake up a large part ofthe Earths crust and are classified bytexture andby chemical and mineral assemblage(metamorphic facies). They may be formedsimply by being deep beneath the Earthssurface, subjected to high temperaturesand the great pressure of the rock layersabove it.