Consortium for Continental Reflection Profiling: COCORP Hardeman County, Texas

The field acquisition unit was a 48- channel MDS 8/Mandrel Data System; geophones were Electro-Technical Laboratory EV22C with a natural frequency of 7Vi Hertz; the VIBROSEIS technique was used, sources being five synchronized vibrators (three Y1100, each of 13V2 ton peak force, and two Y900, each of IOV2 ton peak force). Station spacing: 100 m (330 ft), geophone spread length 4.7 km (15,510 ft). Distance of source station to nearest geophone: 400 m (1,320 ft). 24 geophones per station, spread over a distance of 200 m (660 ft) (100 percent geophone overlap). Vibrator array: (Y900 — Y1100 — Y1100 — Y1100 — Y900) vibrators 18.3 m (60 ft) apart, move-up interval of 6.5 m (20 ft); 16 sweeps summed per record. Pilot signal: 15 sec duration; psweep, 10 to 32 Hertz. 8 msec sampling interval; 30 sec recording duration. Normal vibrator locations were spaced two stations apart.