Remember Caprock
Caprock Technical Terms
Caprock: a) A hard rock layer, usually sandstone, lava or in arid environments, limestone, that lies above shale or other less resistant bedrock or sediments; specifically a rock layer that forms relatively level, resistant topmost strata that holds up hills, ridges, mesas, etc., and commonly forms cliffs or escarpments. Also spelled cap rock. SW & GG b) A hard rock layer, usually sandstone, over-lying the shale above a coal bed. Also spelled cap rock. GG