دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a coarse-grained, foliated metamorphic rock that splits easily into layers. It is formed when shale under deep burial becomes slate and then, with more intense metamorphism, becomes schist.

a crystalline metamorphic rock that can be split into think layers because of the bedded mineral arrangements.