| greensand | <geology> A variety of sandstone, usually imperfectly consolidated, consisting largely of glauconite, a silicate of iron and potash of a green colour, mixed with sand and a trace of phosphate of lime. Greensand is often called marl, because it is a useful fertiliser. The greensand beds of the American Cretaceous belong mostly to the Upper Cretaceous. Source: Websters Dictionary (01 Mar 1998) |
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