T212 Tectonics and Metallogeny

Tuesday, 11 October 2011
1:30 PM - 5:30 PM
Room 101H-J

TOWARDS THE BETTER UNDERSTANDING OF GOLD MINERALIZATION IN THE NORTHERN AREAS OF PAKISTAN

Paper number: T212-5
Program: Technical Sessions
Time: 2:35 PM – 2:50 PM

Authors

Abstract

The geology of the northern Pakistan is a superb example of an area displaying the geological effects of continental collision tectonics. This area experienced two major collisions. The first was between an arc system (Kohistan-Ladakh) and the later was a collision of India-Kohistan with Asia at 50 Ma (Khan et al., 2009). The arc system was ultimately squeezed between Indian and Karakoram terranes. Understanding the sequence of tectonic events that resulted in this remarkable episode of crustal growth is not only scientifically very interesting, it has significant potential for contributing to the economic development of Pakistan with respect to base and precious metals, as well as gemstone occurrences. The occurrence of placer gold in the upper reaches of the Chitral and Gilgit areas and along the Indus River in northern Pakistan has been reported. The occurrence of placer gold has also been proved through drilling and panning along the Indus and Gilgit Rivers. These placer deposits are generally recent in age and occur as thin pockets of heavy mineral concentrate. Gold washing has been a practice for a long period along the Indus and Gilgit rivers in northern areas of Pakistan.

We used geochemical data and geoinformatic tools for delineating the source rocks for gold, silver and other precious metals in the northern areas of Pakistan. For this purpose geochemical data of stream sediments and rocks from previous studies were integrated with remote sensing data. The geochemical data included 4096 samples collected in the Chitral, Gilgit and Skardu regions of the northern Pakistan covering 50,000 sq. km area. Remote sensing data included multispectral (LANDSAT, ASTER and Geoeye) and hypersepctral (Hyperion) data. Several areas showing high concentration of gold in stream sedimentsrocks samples and demonstrating rock alterations were selected for detailed study. This summer field work was carried out, where more samples were collected and remote sensing findings were confirmed. Further work is underway that involves geochemical and mineralogical studies.

REFERENCE

Khan, S. D., Walker, D. J., Hall, S., Burke, K., Shah, M. T., and Stockli, L., 2009. Did Kohistan-Ladakh island arc collide first with India? Geological Society of America Bulletin, 121 (3/4), 366-384.