Metamorphic Rocks

Metamorphic rocks are one of the main groups of rock that are the result of transformation or alteration of a rock type that has been there before, protolith, by a process called metamorfisme, which means "changing forms". Protolith subjected to heat (greater than 150 ° Celsius) and extreme pressure will experience physical changes and / or chemistry major. Protolith can form sedimentary rocks, igneous, or metamorphic rocks, others are older. Some examples are gneis metamorphic rock, slate, marble, and skist.
Metamorphic rocks make most of Earth's crust and are classified on the basis of texture and chemical composition and mineral (metamorphic facies) They formed far below the surface of the earth by the great stress from the rocks above and high pressures and temperatures. They are also formed by the intrusion of molten rock, called magma, into solid rock and is formed mainly at the contact between magma and high-temperature rocks.
Research metamorphic rocks (now exposed at the earth's surface caused by erosion and uplift) provides us valuable information about temperatures and pressures that occur deep within the earth's surface.

Sedimentory Rock

Rock sediment or sedimentary rock is one of the three main rock groups (along with igneous and metamorphosed rocks) are formed through three main ways: weathering of other rocks (clastic); deposition (deposition) due to biogenic activity; and precipitation (precipitation) of solution. Common rock types such as limestone, sandstone, and clay, including the rock sediment. Sediment rocks covering 75% of the earth's surface.
Naming sediment grain size is usually based on the naming of the rock composer is: breccia, conglomerate, sandstone, clay stone

* Breccia is a sedimentary rock with grain size larger than 2 mm with an angular shape butitan
* Conglomerate is a sedimentary rock with grain size larger than 2 mm in the form of granules which membudar
* Sandstone is a sedimentary rock with grain size between 2 mm to 1 / 16 mm
* Stone silt is sedimentary rock with grain size between 1 / 16 mm to 1 / 256 mm
* Stone clay is a sedimentary rock with grain size smaller than 1 / 256 mm

Igneous Rock

Igneous rock or igneus (from the Latin ignis, "fire") is a type of rock formed from magma that cools and hardens, with or without crystallization, either below the surface as intrusive rocks (plutonic) or above the surface as a rock extrusive (volcanic). This magma can be derived from a half-molten rock or rock that already exist, either in the mantle or crust of the earth. Generally, the melting process occurs by one of the following processes: the increase of temperature, pressure drop, or change in composition. More than 700 types of igneous rocks has been described, largely formed beneath the surface of the earth's crust.