Gravity field of the buried shield in the Punjab Plain, Pakistan

The regional Bouguer anomaly data of the Punjab Plain, Salt Range, and Potwar Plateau, covering an area of about 135,000 km 2 (lat 29°00′ to 33°30′N, long 71°00′ to 74°30′E), have been determined. Inferences have been drawn on the assumption that the gravity anomalies reflect the buried features of the Precambrian basement, with density of 2.7 g/cm 3 as compared to an average of 1.9 g/cm 3 for the sedimentary cover. The Sargodha–Shah Kot ridge of the Punjab Plain is inferred to be a horstlike block of raised continental crust extending northwestward with gentle dips. Our interpretation of the gravity data indicates that the shield elements with increasing sedimentary cover can be followed northward beneath the southward thrust of the Himalayas, as suggested by Gansser.