Coquinas accumulate in high-energy marine and lacustrine environments where currents and waves result in the vigorous winnowing, abrasion, fracturing, and sorting of the shells that compose them. As a result, they typically exhibit well-developed bedding or cross-bedding, close packing, and good orientation of the shell fragments. The high-energy marine or lacustrine environments associated with coquinas include beaches, shallow submarine-raised banks, swift tidal channels, and barrier bars.