'''Shale''', sometimes called ''Mudstone'' is a fine-grained [[sedimentary rock]] made from clay or mud. Shale is the most common type of sedimentary rock, and a large proportion of [[fossils]] are found in it. | '''Shale''', sometimes called ''Mudstone'' is a fine-grained [[sedimentary rock]] made from clay or mud. Shale is the most common type of sedimentary rock, and a large proportion of [[fossils]] are found in it. |