Geochronology and Mammalian Paleobiogeography of the Ghazij Formation, Pakistan: Implications for the Indian-Asian Collision and the Paleocene-Eocene Boundary

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Recent discovery of fossil terrestrial mammals in the relatively undeformed paralic and continental sediments of the lower Eocene Ghazij Formation, Baluchistan Province, Pakistan provides a unique opportunity to investigate the paleogeography and paleobiogeography of the critical region between Indo-Pakistan and Asia before final suturing. This award supports an investigation of the geochronology, paleogeography, and paleobiogeography of the Ghazij Formation in order to test the hypothesis that the "modern" orders of mammals (primates, artiodactyls, and perissodactyls) originated on the Indo-Pakistan continent before collision and dispersed across the holarctic after collision. The geochronology of the Ghazij will be evaluated using magnetostratigraphy since there are no known isotopically dateable horizons and preliminary paleomagnetic results suggest that many Ghazij facies are conducive to this methodology. Paleogeography will be reconstructed using sandstone paleocurrent and provenance analysis in order to evaluate the location and composition of the source region for the fluvial sediments in the middle and upper Ghazij Formation. Ghazij paleobiogeography will be evaluated by continued sampling of vertebrate faunas and comparison of these assemblages to similarly aged vertebrate faunas from Asia, Europe, and North America. The coarse conglomerates and continental facies of the upper Ghazij Formation may represent the sedimentary response to initial Indo-Asian collisional deformation and thus could help resolve ongoing debates related to the timing and geometry of this important tectonic event.