Bedrock: Difference between revisions
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A solid [[geologic map]] of an area will usually show bands of differing rock type; i.e., rock that would be exposed at the surface if all [[soil]] or other superficial deposits were removed. The different rock strata or layers that are indicated may be a result of either nonparallel (sloping) surface [[erosion]] at the edges of flat strata or normal surface erosion of tilted strata that has removed the upper portions of higher layers. |
A solid [[geologic map]] of an area will usually show bands of differing rock type; i.e., rock that would be exposed at the surface if all [[soil]] or other superficial deposits were removed.{{citation needed|date=September 2009}} The different rock strata or layers that are indicated may be a result of either nonparallel (sloping) surface [[erosion]] at the edges of flat strata or normal surface erosion of tilted strata that has removed the upper portions of higher layers.{{citation needed|date=September 2009}} |
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== References == |
== References == |
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Revision as of 05:09, 3 September 2009
 | This article needs additional citations for verification. (October 2008) |
In stratigraphy, bedrock is the native consolidated rock underlying the surface of a terrestrial planet, usually the Earth. Above the bedrock is usually an area of broken and weathered unconsolidated rock in the basal subsoil. The top of the bedrock is known as rockhead and identifying this, via excavations, drilling or geophysical methods, is an important task in most civil engineering projects. Superficial deposits (also known as drift) can be extremely thick such that the bedrock lies hundreds[1] or even thousands[2] of metres below the surface.
A solid geologic map of an area will usually show bands of differing rock type; i.e., rock that would be exposed at the surface if all soil or other superficial deposits were removed.[citation needed] The different rock strata or layers that are indicated may be a result of either nonparallel (sloping) surface erosion at the edges of flat strata or normal surface erosion of tilted strata that has removed the upper portions of higher layers.[citation needed]