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Four left-stepping pressure ridges extend for nearly 60 km parallel and close to the southern margin of the Peshawar basin, cutting diagonally across older imbricate thrust structures of the Attock-Cherat Range. Lacustrine, fluvial, and alluvial-fan deposits dated at 2.8 to 0.6 Ma are strongly folded, faulted, and eroded prior to deposition of alluvial-fan gravels, which are themselves cut by east-northeast–trending faults with their north sides upthrown. The pressure ridges postdate some of the fan drainage but deflect other drainage. The east-northeast–trending faults are high-angle and accompanied by instrumental seismicity; there is no evidence for strike-slip except for the en echelon distribution of the ridges and low-angle slickensides on one of the faults. Alluvial-fan and fluvial sediments are folded and faulted at Tarbela Dam, 40 km east-northeast of the easternmost pressure ridge, and the base of Indus River gravels is apparently displaced by a reverse fault with the northwest side up. Farther north, a fault adjacent to Tarbela Lake has left-lateral displacement. Additional lineations and south-facing scarps occur throughout the Attock-Cherat Range, and Jurassic limestone is faulted over gravels at the western end of the Nizampur basin. We interpret these features as part of a broad zone of deformation involving seismogenic crust; direction of slip is south-southwest. There is no evidence of surface rupture in this zone during Holocene time.

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