Download
1 / 7
E N D
Rock cycle Rocks are composed primarily of minerals and can be an amalgam of different minerals or can be composed of one mineral. Over 3500 minerals have been identified most of these can be found in the earth's crust. Some of the earth's minerals are exceedingly popular - fewer than 20 minerals compose more than 95% of the earth's crust
Minerals A rock is defined as an aggregate of mineral grains, which means that rocks are a bunch of mineral grains all stuck together. The mineral grains may be large enough to be seen with the naked eye phaneritic or microscopic aphanitic.
Fossils Some animals were quickly buried after their death (by sinking in mud, being buried in a sandstorm). Over time more and more sediment covered the remains. The parts of the animals that didn't rot (usually the harder parts like bones and teeth) were encased in the newly formed sediment. In the right circumstances (when there is no scavengers, quick burial, not much weathering) parts of the animal turned into fossils over time
Sedimentary Rock Sedimentary rocks form at or near the earth's surface from the weathered remains of pre-existing rocks or organic debris.
Metamorphic Rock Metamorphic rock is rock that has changed from one type of rock into another.
Igneous Rock The first rocks on earth were igneous rocks. Igneous rocks are formed by the cooling and hardening of molten material called magma.
