Sedimentary Rocks Journals

Sedimentary rocks are sorts of rock that are formed by the build up or deposition of small particles and subsequent cementation of mineral or organic particles on the ground of oceans or other bodies of water at the surface. Common sedimentary rocks include sandstone, limestone, and shale. These rocks often start as sediments carried in rivers and deposited in lakes and oceans. When buried, the sediments lose water and become cemented to make rock. Tuffaceous sandstones contain volcanic ash. Biologic sedimentary rocks form when large numbers of living things die. Chart may be a example for this sort of rock, and this is often one among the ways limestone can form. Limestone also can form by precipitating out of the water. Clastic sedimentary rocks are the group of rocks most of the people consider once they consider sedimentary rocks. Clastic sedimentary rocks are made from pieces of pre-existing rocks. Pieces of rock are loosened by weathering, and then transported to some basin or depression where sediment is trapped. If the sediment is buried deeply, it becomes compacted and cemented, forming rock. Classic sedimentary rocks may have particles ranging in size from microscopic clay to large boulders. Their names are supported their class or grain size. The littlest grains are called clay, then silt, then sand. Grains larger than 2 millimeters are called pebbles. Shale may be a rock made mostly of clay, siltstone is formed from silt-sized grains, sandstone is formed of sand-sized clasts, and conglomerate is formed of pebbles surrounded by a matrix of sand or mud.