Laminated and nonlaminated sandstones, shales, mudstones, siltstones, shaly conglomerates, and breccias are the principal rock types represented in the Mam Tor sandstone member of the Kinderscoutian stage of the Namurian (Carboniferous). They form a thick monotonously repeated cyclothem, in which the grain size decreases upwards. The sandstone-shale groups persist laterally, and are characterized by the development of groove, flute, load, sludge, and trail casts on sharp soles. Convolute, corrugated, and crumpled bedding and slump-ball structures are often found. The Mam Tor sandstones are considered to have been deposited by turbidty currents, originating in slumps of shallower delta sediments coexisting higher on the submarine slopes, which flowed east-west and later flowed southward into the quiet deep waters where marine shales were already depositing.