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The magnetic polarity stratigraphy and age of the Siwalik group near Dhok Pathan village, Potwar Plateau, Pakistan

1978; Elsevier BV; Volume: 41; Issue: 3 Linguagem: Inglês

10.1016/0012-821x(78)90190-5

1385-013X

J. Barndt, Noye M. Johnson, Gary D. Johnson, Neil D. Opdyke, Everett H. Lindsay, David Pilbeam, R.A.H. Tahirkheli,

Geological formations and processes

The magnetic polarity zonation of the terrestrial strata exposed in the Dhok Pathan area of Pakistan has been established utilizing data from 204 paleomagnetic sites. Individual magnetic transitions are traced laterally over 15 km and provide convenient time lines for correlating the fluvial facies of the middle Siwalik Group. A pervasive, normal polarity zone dominates throughout the region and has been interpreted as Magnetic Polarity Epoch 9. Based on this interpretation and using the absolute ages from the published magnetic time scales the average sedimentation rate in the area is calculated at 0.8 m/1000 years, and the average elapsed time between fluvial cycles is 56,000 years. Major sandstone units are minimally time transgressive in an east-west direction. The Nagri Formation in the Dhok Pathan area spans the time from 10.0 to 8.6 m.y. B.P.Ramapithecus and other hominoid primates are found in Epoch 9 at about 9 m.y.