Impact of Indo-Pakistan and Eurasian Plates Collision in the Sulaiman Fold Belt, Pakistan

Khan, Iqbal M.¹
(1)Exploration, Pakistan Petroleum Limited, Karachi, Pakistan.

The Sulaiman Fold Belt has a complex tectonic setting as it is located in the collision zone of Indo-Pakistan and Eurasian plates with the left-lateral Chaman fault in the west and the Himalayan fault and thrust system in the north. The Indian Shield, with pre-Cambrian basement rocks, is exposed in the east.

The Himalayan chain is primarily resulting from the north south collision of the Indo-Pakistan and Afghan Block (Eurasian) plates. The resulting consuming margin extends from Pakistan through India, Nepal and Myanmar. To the west of this collision zone, a consuming boundary is present between the Arabian and Persian plates. During the collision process, the sedimentary overburden detached from the crystalline basement of the Indian Shield. The sea floor of Neo-Tethys is preserved as Bela-Waziristan Ophiolite Zone.

In Pakistan, the oblique collision of Indo-Pakistan and the Eurasian plates led to the formation of Kirthar-Sulaiman fold belt involving Mesozoic through Cenozoic sediments. The colliding converging plates have strongly deformed the sediments deposited on the shelf and frontal part of Indo-Pakistan Plate. Subsequently due to strong orogenic events marine sedimentation changed to terrestrial one followed by more than 3500 m thick coarse grained fluvial sediments of the Siwalik Group deposited in the Indus Foredeep, which is considered as a hydrocarbon kitchen area.

This paper discusses different concepts about the tectonics of the eastern Sulaiman Fold Belt, Pakistan which was previously interpreted in terms of thin-skinned and strike-slip / wrench tectonics. Present work is based on interpretation of satellite images and geological fieldwork, which concludes that area under discussion, has been developed as a “Positive-Flower Structure” due to left-lateral strike-slip movement in the basement of the Indo-Pakistan Plate. In the overlying sediments its impact can be substantiated only after the deposition of the Upper Siwaliks that is not more than 0.7 million years old.

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.