During recent years the use of a heavy weight hitting the earth as a source of energy in reflection seismograph work has increased considerably, particularly in the Delaware and Val Verde basins of West Texas and New Mexico. The thumping procedure allows the replacement of shotholes, drill bits, and explosives with a weight-drop truck, thereby allowing a saving of up to several thousand dollars per month over conventional pattern shooting. One thumping technique that can be used involves a procedure in which each drop in a thump pattern is recorded into a full spread of geophones. A modified FM tape recording truck of the type normally used on pattern shooting crews is employed to record the weight-drop energies. Raw field tapes are composited and corrected for weathering, elevation, and normal moveout in a playback center. Comparisons of pattern shooting and thumping in the Delaware and Val Verde basins verify that in most areas of the 2 basins the thumping technique does provide data that is as usable as shooting data. Examples of data obtained by using the procedure described in this paper are presented, showing a regional line, a fault crossing, and steeply-dipping horizons.