During the late Oligocene and early Miocene paleodrainage and deposition in the western Himalayan foreland consisted of two distinct and dominant systems: 1) fluvio-deltaic sediments from the Indus River to the Katawaz Basin region near the Chaman Fault system and 2) marginal marine deposits in the western and northwestern portion of the foreland. The paleocurrent record of the Chitarwata Formation and overlying Vihowa Formation at Zinda Pir Dome developed in this study indicates an appreciable interval during the late Oligocene and early Miocene in which the northwest portion of the foreland basin included a coastline with drainage chiefly from the northwest towards the southeast. These results are consistent with the general pattern of southeastern drainage in the western Himalayan foreland since the Eocene. The Chitarwata shoreline demarcated an edge of the ebbing Tethys-sea-marine foredeep and was structurally isolated from the main sediment flux of the Indus River to the Katawaz Basin further to the west. Conspicuous differences in character of lithostratigraphy, paleoenvironments, and vertebrate preservation between the Bugti Hills and Zinda Pir areas in the Chitarwata Formation advocate that the more southerly “Bugti member” of Chitarwata with its exceptional vertebrate faunas was actually a phase of fluvio-deltaic sedimentation related to the Shaigalu Fan of the Katawaz Basin.
Kevin F. Downing. DePaul University, Chicago, Illinois 60604, USA.
Everett H. Lindsay. Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA.
KEY WORDS: Himalayas, Indus River, Miocene, Paleocurrents, Paleodrainage, Paleogeography
PE Article Number: 8.1.20A
Copyright: Paleontological Society May 2005.
Submission: 30 June 2004. Acceptance: 6 March 2005