Stratigraphy and Depositional Environments of the Paleogene of the Potwar Plateau, Northern Pakistan

RESSETAR, ROBERT, and KHALID PARVEZ, University of South Carolina, Columbia, SC, and M. R. GROSS, Pennsylvania State University, University Park, PA

The Paleogene sequence in the Potwar Plateau of northern Pakistan is dominated by carbonates and shales, representative of the final marine sedimentary episode along the southern Neo-Tethys. Measured sections at 16 locations on the perimeter of the plateau were used to reconstruct the Paleogene depositional environments.

The lowest Paleogene deposits comprise a widespread basal transgressive clastic unit (Hangu Formation) overlain by a shallow shelf limestone (Lockhart Formation). Across much of the plateau, the Lockhart was followed by euxinic, deep-water calcareous shale (Patala Formation), which grades southeastward (cratonward) into coal-bearing paralic deposits. The overlying Nammal, Sakesar, and Chor Gali formations record gradual shallowing of the basin, with inner shelf and intertidal carbonates prograding over deep-water limestones. Regression culminated in red bed (Mami Khel Formation) and evaporite deposition.

Although a second, limited transgression resulted in renewed limestone deposition (Kohat Formation) in the north and west, the bulk of the Paleogene represents a single transgressive-regressive cycle. This cycle can be correlated with published descriptions of the Paleogene on the northern margin of most of the Indo-Pakistan subcontinent.

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)