Rock Cycle • It is the continual process of new rock being turned into old rock. • Each type of rock can be changed into every other type of rock. • The sequence of events in the rock cycle depends on the processes that the rocks go through and where is it located in the Earth or the rocks surroundings.
Igneous Rocks • Igneous rocks start out as magma. • Magma is created in 3 ways. • When rock is heated. • When pressure is released. • When the composition of the rock changes.
Igneous Rocks • Magma cools down to form igneous rock. • Extrusive Igneous Rock – This is formed on the Earth’s surface. Ex. Mid-ocean Ridge • Intrusive Igneous Rock – This is formed below the Earth’s surface.
Sedimentary Rocks • Sedimentary rocks are formed as sediment is deposited and lower layers become compacted. Dissolved minerals separate to form a natural glue that binds the sediments together. • Sedimentary rocks have a distinctive layering or strata.
Sedimentary Rocks • Clastic Sedimentary Rock • When rock or mineral fragments are cemented together. Ex. Shale • Chemical Sedimentary Rock • When minerals crystallize out of solution of minerals and water. • Organic Sedimentary Rock • Form from the remains of living things.
Metamorphic Rocks • Form when pressure and temperature act on a rock. • Metamorphose is when rocks melt to become magma and then igneous rocks.
Composition of Metamorphic Rocks • Metamorphism occur when the temperature and pressure inside the Earth’s crust change. • Because not all minerals are stable, minerals can react chemically with one another to change into another more stable mineral.
Composition of Metamorphic Rocks • Some minerals only form in metamorphic rock. Some metamorphic minerals only form in a certain range of temperatures and pressure conditions.
Texture of Metamorphic Rocks • Foliated Metamorphic Rocks - Minerals that are arranged in planes or bands. These tend to be rocks with a variety of minerals. Ex - gneiss • Nonfoliated Metamorphic Rocks - Minerals that do not appear to be arranged in a pattern. Ex - marble