Detrital Zircon Provenance of the Cenozoic Sequence, Kotli, Northwestern Himalaya, Pakistan; Implications for India–Asia Collision

Muhammad Awais,Muhammad Qasim,Mirza Shahid Baig,Maryam Sattar,Shahab Pervaiz,Lin Ding,Javed Iqbal Tanoli

doi:10.3390/min11121399

Abstract

This study reported the detrital zircon U-Pb geochronology of the Cenozoic sequence exposed in Kotli, northwestern Himalaya, Pakistan, which forms part of the Kashmir foreland basin. The U-Pb detrital age patterns of the Paleocene Patala Formation show a major age cluster between ~130–290 Ma, ~500–1000 Ma and ~1000–1500 Ma, which mainly resembles the lesser and higher Himalayan sequence. However, the younger age pattern (~130–290 Ma) can be matched to the ages of the ophiolites exposed along the Indus–Tsangpo suture zone. In addition, two younger grains with 57 Ma and 55 Ma ages may indicate a contribution from the Kohistan-Ladakh arc. The detrital zircons in the upper Tertiary sequence show the increased input of younger detrital ages <100 Ma, with more pronounced peaks at ~36–58 Ma, ~72–94 Ma and ~102–166 Ma, indicating the strong resemblance to the Asian sources including the Kohistan–Ladakh arc, Karakoram block and Gangdese batholith. This provenance shift, recorded in the upper portion of Patala Formation and becoming more visible in the upper Tertiary clastic sequence (Kuldana and Murree formations), is related to the collision of the Indian and Asian plates in the northwestern Himalayas. Considering the age of the Patala Formation, we suggest that the Indian and Asian plates collided during 57–55 Ma in the northwestern Himalayas, Pakistan.

Highlights

The detrital zircon U-Pb ages show a major provenance change occurred in the upper part of the Patala Formation, which is more pronounced in the upper Tertiary Kul
This indicates that it is more likely associated with the India–Asia collision in northern Pakistan
The mixed provenance in the Patala Formation suggest that the ophiolites exhumed during the Late Paleocene contributed the source to the evolving foreland basin together with Kohistan Island arc and the Indian craton

Summary

Introduction

The timing and location of the India–Asia collision has remained a hotly debated topic in the last two decades, which resulted in a wide range of collision ages along the strike [1]. This difference in the collision age is due to various methods adopted to constrain the collision timing. In this study, we have selected an area southeast of the Balakot in the same basin to study the Cenozoic sequence for stratigraphic characterization and their tectonic implications in relation to the India–Asia collision

Methods

Discussion

Conclusion