Coarse grained (rudaceous) rock with rounded clasts that are greater than 2 mm in size. Conglomerates may be termed ‘intraformational’ if formed of local, recently deposited clasts, or ‘extraformational’ if the clasts are derived from outside the area of deposition. The term ‘polygenetic’ is used to describe a conglomerate rock that has been produced under a variety of conditions or processes.