Rocks
By: Sam Sosa
Types of Rocks
Igneous Rock
Igneous rock is formed through the cooling and solidification of magma or lava.Igneous rocks are also formed when volcanoes erupt and is formed as the lava cools above ground. Two main types of igneous rock are intrusive and extrusive rocks. Intrusive is formed by the cooling of magma deep in the Earth which is typically much slower than the cooling process at the surface, so larger crystals can grow. Extrusive form by the crystallization of magma at the surface of the earth.
Sedimentary Rock
Sedimentary rocks are formed when sediment is deposited out of air, ice, wind, gravity, or water flows carrying the particles in suspension. This sediment is often formed when weathering and erosion break down a rock into loose material in a source area. There 3 main types of Sedimentary rocks called Clastic, Chemical, and organic. Clastic sedimentary rocks may have particles ranging in size from microscopic clay to huge boulders.Chemical sedimentary rocks form by precipitation of minerals from water.Organic sedimentary rocks form from the accumulation and lithification of organic debris, such as leaves, roots, and other plant or animal material.
Metamorphic Rock
Metamorphic rock are physically deformed and chemically changed due to different temperatures and pressures.They may be formed simply by being deep beneath the Earth's surface, subjected to high temperatures and the great pressure of the rock layers above it. Two main types of metamorphic rock are Foliated and Non-foliated. At the lowest metamorphic grade is the foliated metamorphic rock slate. Slate generally forms by the realignment of clay minerals in the precursor rock shale at low temperatures and pressures. Non-foliated metamorphic rocks are formed around igneous intrusions where the temperatures are high but the pressures are relatively low and equal in all directions
The Rock Cycle
The Rock Cycle
The Rock Cycle is a group of changes Igneous rock forms when magma cools and makes crystals. Magma is a hot liquid made of melted minerals. The minerals can form crystals when they cool. Igneous rock can form underground, where the magma cools slowly. Or, igneous rock can form above ground, where the magma cools quickly.