sedimentary rock

Sedimentary rock is one of the three main rock types (the others being igneous and metamorphic rock). Sedimentary rock is formed by deposition and consolidation of mineral and organic material and from precipitation of minerals from solution. The processes that form sedimentary rock occur at the surface of the Earth and within bodies of water. Rock formed from sediments covers 75-80% of the Earth's land area, and includes common types such as limestone, chalk, dolostone, sandstone, conglomerate, some types of breccia, and shale.^[1]

Sedimentary rocks are classified by the source of their sediments, and are produced by one or more of:

• clastic rock formed from fragments broken off from parent rock, by
  • weathering in situ or
  • erosion by water, ice or wind

followed by transportation of sediments, to the place of deposition;

• biogenic activity; or
• precipitation from solution.

The sediments are then compacted and converted to rock by the process of lithification.