An Insight Into the Southern Fringe of Peshawar Basin as A New Frontier for Hydrocarbon Exploration In North Pakistan

Abstract

The southern fringe of the Peshawar Basin is marked by the juxtaposition of metasediments of the Lesser Himalaya in the north with the Mesozoic to Neogene fold belt sediments in the south. These juxtaposed transitional rock assemblages outcrop along the Attock-Cherat ranges and extend westwards into the Khyber Agency. At the northern fringe of the Attock-Cherat ranges, partly metamorphosed Precambrian continental shelf clastics of the Manki Formation are thrust southwards over the deep marine flysch sequence of the Dakhner Formation along the Khairabad-Panjal Thrust. The Dakhner flysch sedimentsare unconformably overlain by the Paleocene rocks with no pre-Paleocene outcrops. The flysch sequence is in turn thrust over an unmetamorphosed Paleozoic rock sequence in the south along the Cherat Fault. The Paleozoic sequence isunconformably overlain by the Paleocene rocks, and this whole sequence is in turn thrust southwardsover the Mesozoic rock sequences of the Kalachitta Range, along the Hissartang Fault. The Paleocene stratigraphy is common in the mentioned transitional zone and the fold belt to the south, suggesting an earlier pre-Paleocene tectonic activity along the southern fringe of the Peshawar basin which produced large thrust nappes exposed at surface as Khairabad-Panjal, Cherat and Hissartang Fault. These pre-Paleocene nappes were re-activated during post Miocene Himalayan deformation as suggested by the involvement of the Miocene rocks along the surface trace of these nappes. Based on the structural and stratigraphic set up of the southern fringe of the Peshawar Basin, we propose that the marine shelf of the Indus Basin was extended up to the Peshawar Basin during the Mesozoic time and has deposited the Mesozoic marine strata within the Peshawar Basin. Later on this marine succession was buried by the pre-Paleocene thrust nappes of the Attock-Cherat ranges. It is also proposed that a potential petroleum system may be present underneath these thrust nappes in the buried Mesozoic marine strata. The metamorphism within the

AAPG Datapages/Search and Discovery Article #90217 © 2015 International Conference & Exhibition, Melbourne, Australia, September 13-16, 2015