| dc.description.abstract | North Pakistan represents a highly favourable area for a variety of mineral
deposit types, including arc-related porphyry Cu, Au and Mo and arc and backarc
epithermal precious metal deposits (Sweatman et al., 1995; PMDC, 2001).
However, few deposits have been discovered in the area, mainly due to its
remote nature and inaccessibility, and because of a lack of exploration tools for
high altitude terrains. From stream sediment sampling campaigns by local and
international organizations, including a large dataset provided by the Pakistan
Mineral Development Corporation (PMDC), a significant amount of geochemical
data now exists for the region. This data has been incorporated into an Arc-GIS
9.2 database, along with stream catchment and geological information, and
detail of all known areas of mineralisation. From this, spatial catchment maps
together with multi-element geochemical associations have been studied to
delineate areas showing anomalous values for Au and base metals. The two
most prospective areas were found to be the Shyok Suture Zone and northern
Kohistan, with the dominant control on mineralisation being structural rather
than lithological. These areas were targeted for detailed stream sediment
sampling and mineralogical and geochemical analysis. From studies of Au and
Au pathfinder elements in different size fractions of the stream sediments and
heavy mineral concentrates (HMC), the catchments of Teru, Asheriat and
Pakora (in order of decreasing rank) were identified as most prospective.
Morphological and geochemical analyses of native Au grains from panned
concentrates has given an indication of proximity to bedrock source (<10 km)
and the possible styles of mineralisation in these catchments; porphyry Cu-type
in Asheriat and Pb-Sb quartz veins in Teru and Pakora. Automated
mineralogical analysis of the stream sediments (<180 µm fraction) and HMC
(<180 µm), using a QEMSCANÒ system, confirmed this interpretation. The
effectiveness of the developed methodologies for exploration in remote and
high altitude terrains of North Pakistan is discussed, and recommendations
made for future exploration. | en_GB |
