出典:Wiktionary
bedrock (countable かつ uncountable, 複数形 bedrocks)
In mountainous regions, bedrock can be seen at the surface. However, these occurrences are more properly called outcrops. In construction and engineering, it is often desired to place foundations on bedrock in order to improve the stability of a structure.
bedrock (三人称単数 現在形 bedrocks, 現在分詞 bedrocking, 過去形および過去分詞形 bedrocked)
出典:Wikipedia
出典:『Wikipedia』 (2011/07/06 17:33 UTC 版)
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 so that the bedrock lies hundreds of metres below the surface.