Locating earliest records of orogenesis in western Himalaya: Evidence from Paleogene sediments in the Iranian Makran region and Pakistan Katawaz basin

A combination of sediment petrography, detrital zircon U-Pb, and fission-track dating is used to show that provenance of the Paleogene sedimentary rocks exposed in the Makran region of southern Iran and the Katawaz basin of Pakistan is consistent with a source from the nascent western Himalaya and associated magmatic arc. Results from this important archive show that Paleogene erosion was focused mainly on the arc and northern Indian margin, and, in contrast to the east-central Himalaya, we have not detected widespread rapid exhumation indicative of strong forcing by climate-driven erosion at that time.