Why are sedimentary rocks found only at surface of the earth?

Answer 1

The sea is the final repository for transported eroded sediments. The weight of the accumulating sediments actually sinks the crust, making room for more overlying sediments. Eventually the sediments are lithified by pressure from above.

Answer 2

Sedimentary rock is a type of rock that is formed by sedimentation of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles (detritus) to settle and accumulate or minerals to precipitate from a solution. Particles that form a sedimentary rock by accumulating are called sediment. Before being deposited, sediment was formed by weathering and erosion in a source area, and then transported to the place of deposition by water, wind, mass movement or glaciers which are called agents of denudation.

The sedimentary rock cover of the continents of the Earth's crust is extensive, but the total contribution of sedimentary rocks is estimated to be only 8% of the total volume of the crust.[1] Sedimentary rocks are only a thin veneer over a crust consisting mainly of igneous and metamorphic rocks.

Sedimentary rocks are deposited in layers as strata, forming a structure called bedding. The study of sedimentary rocks and rock strata provides information about the subsurface that is useful for civil engineering, for example in the construction of roads, houses, tunnels, canals or other constructions. Sedimentary rocks are also important sources of Natural Resources like coal, fossil fuels, drinking water or ores.

The study of the sequence of sedimentary rock strata is the main source for scientific knowledge about the Earth's history, including palaeogeography, paleoclimatology and the history of life.

The scientific discipline that studies the properties and origin of sedimentary rocks is called sedimentology. Sedimentology is both part of geology and physical geography and overlaps partly with other disciplines in the Earth Sciences, such as pedology, geomorphology, geochemistry or structural geology.

Answer 3

They are formed beneath the earth, but because of tectonic activity they are sometimes brought to the surface and form into a mountain, with time the mountains will erode and the rocks will be exposed to the surface

Answer 4

Deformation is a general name given to the processes that create twisted, folded and tilted rock strata. Extensional or compressional forces squeeze or stretch the layers, and they deform along planes of weakness. This can also cause uplift, followed by erosion at the Earths surface exposing the layers. Uplift can also be caused by rising hot fluids, gases or magma.

Answer 5

They are not found only at the surface. Some sedimentary deposits can be several miles thick. However, sedimentary rocks are often found at or near the surface because they form from sediment that was laid down on Earth's surface, usually at the bottom of a body of water.

Answer 6

That's because they have just been recently deposited.

Answer 7

Sedimentary rocks from by a process of erosion of other rocks, deposition, (usually) burial, and lithification. This can only happen at the surface.