Structural traps, such as anticlines and fault traps, and structural leads (possibilities of traps which require more work to define them completely) are usually evident from examination of the maps. Traps resulting from pinch-outs and unconformities are more difficult to recognize and nonseismic evidence often must be combined with seismic data to define such features. Nevertheless, careful study of the maps, sections and records plus broad experience and ample imagination will at times disclose variations of dip or other effects which help locate traps of these types.