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The study area, covering Golo Das and surrounding areas, is a part of Ghizar district in Gilgit-Baltistan province, Pakistan. Geologically the study area is located at the northern margin of Kohistan island arc adjacent to the Shyok Suture Zone / Main Karakorum thrust and is mainly composed of the rocks of Shamran / Teru volcanics, Chalt volcanic group and meta-sediments intruded by Kohistan batholiths. Field studies show that the Chalt volcanics are green in color, highly foliated and sheared rocks with intensive quartz veining along the shear zones. At some places these veins contain sulfide bearing phases, especially pyrite in higher amount. The Shamran / Teru volcanics are fine-grained, green to greyish-green colored compact rocks. Sulfide mineralization in the form of chalcopyrite, tetrahedrite and pyrite is noticed along shear zones and in the vicinity of thick marbalized beds and silicified alteration zones within the Shamran / Teru volcanics. The leaching of these sulfides into malachite and azurite is very common. At certain places pods like iron ore, containing magnetite, limonite and specularite, were also found in the vicinity of the marbalized and silicified alteration zones. The dioritic intrusions, a part of the Kohistan batholiths, are well exposed in the area and exhibit chilling effects in contact with the Shamran / Teru volcanics. Bulk samples (>10 kg) were collected from the fresh rocks and altered/sulfide zones for laboratory investigations. These samples were crushed through jaw crusher and then pulverized to -200 mesh size by the tungsten carbide ball mill. Representative portion of the sample was treated with aqua regia (3HCL:1HNO3 ) for base and other metals (i.e., Ag, Cu, Pb, Zn, Cr, Ni, Co, Cd) while the gold (Au) was extracted in the methyle isobutyle ketone (MIBK). The concentrations of Au, Ag and other metals were determined by Perkin Elmer 700 electrothermal atomic absorption spectrometer . Au is ranging from 3ppb to 112ppb, Ag from <0.1ppm to 3ppm, Cu <1ppm to 3496ppm, Zn from <0.1ppm to 50ppm, Pb from >1ppm to 7ppm, Ni from <1ppm to 48ppm, Cr from <1 to 182ppm, Co from 3ppm to 56ppm and Cd from 1ppm to 6ppm. The field and geochemical studies suggest that the alteration/sulfide zones in the study area have possible potential for the occurrence of gold. Detailed study of these alteration zones and other rocks in the area is in the process to get information about the genesis of mineralization. [ABSTRACT FROM AUTHOR]

Shigari Bala area, a part of the Skardu district, is the main focus of this study. It is located southwest of Skardu town in the Gilgit-Baltistan province. Tectonically the study area is a part of the Laddakh arc domain of the Kohistan-Laddakh island arc (KLIA). The geology of the study area consists of meta-sediments and meta-volcanics intruded by diorites belonging to the Kohistan batholith. The meta-volcanics (greenschists) are green colored, highly foliated and sheared rocks having greater resemblance with the Chalt volcanics. The meta-sediments are fine- grained, green to gray colored rocks with well-developed fabrics. Diorite occurs as intrusive bodies within the meta-volcanics where the honfelsic rocks are found at the contact zones. The Cu-bearing sulfide mineralization is dominantly chalcopyrite with lesser amount of bornite along with pyrite is noticed within the diorites and also along sheared zone within the hornfelse. At certain places porphyry type copper mineralization is well observed within the diorite, where leaching of the Cu-bearing phases to malachite and azurite is common. Due to the presence of visible copper mineralization in the study area, the geochemical investigations of the rocks of the area was carried out in regard to gold, silver and other base metals. For this purpose, bulk samples (>10kg each) from the various rocks, especially mineralized diorites, have been collected during field. These samples were crushed to smaller size by the Jaw-crusher and then powdered to -100 mesh size by the tungsten carbide ball mill. Representative portion of each sample was selected for chemical analysis by quartering and conning method. The known quantity of powdered sample was digested by using hydrofluoric acid and aqua regia (1HNO3:3HCL) for the analysis of gold, silver and other base metals. The analysis of Au, Ag, Cu, Pb, Zn, Ni, Cr, Co and Cd were performed by the Perkin Elmer 700 electrothermal atomic absorption (AA). Gold was extracted in methyle isobutyle ketone (MIBK) before its determination by AA. The concentration of Au, Ag, Cu, Pb, Zn, Ni, Cr, Co and Cd occur in the range of 1ppb to 545ppb, <0.05ppm to 5ppm, 8ppm to 254ppm, <0.1ppm to 9ppm, <0.1ppm to 131ppm, 2ppm to 40ppm, 4ppm to 88ppm, 2ppm to 82ppm, and <01ppm to 3ppm respectively. The occurrence of copper-bearing sulfides and the geochemical anomaly of Cu and Au in the diorites of the study area are indicative of the existence of possible source rock for Cu and Au. The detailed study of the area in regard to the genesis of mineralization and its economic potential is underway [ABSTRACT FROM AUTHOR]

Bagrot valley, a study area of this research, is located in Giligit district of the Gilgit-Baltistan province in the northern areas of Pakistan. The geology of the area is mainly comprised of the Chalt volcanics and diorites belonging to Kohistan island arc (KIA). Chalt volcanics covers most part of the study area. These are strongly deformed, metamorphosed, and intensely sheared along shear zones. The diorites occur in the southern part of the study area and have intrusive contact with the Chalt volcanics. Yellowish-brown color staining due to the oxidation of sulfide bearing phases, especially pyrite and chalcopyrite, to limonite is very prominent along the shear zones within the Chalt volcanics and also along the contact zones with diorite. At places the development of malachite and azurite are also noticed in association with the Cubearing sulfides. These sulfide bearing zones are <1m to >10m thick and are extended up to >100m. The rocks of the area, especially the sulfide bearing zones, are the main focus of this study in regard to gold, silver and base metal mineralization. To understand the chemical potential of the rocks of the area, bulk samples (>10kg) were collected in the field from both fresh rocks and sulfide bearing zones. These samples were treated for the chemical concentration of Au, Ag, Cu, Pb, Zn, Ni, Cr, Co, and Cd. The samples were crushed to 2mm size in jaw crusher and then pulverized to -100 mesh size by the tungsten carbide ball mill. Representative portion of each sample was digested with hydrofluoric acid, aqua regia (3HCl:1HNO3) and other acid mixtures. These working solutions were used for the determination of base metals by Perkin Elmer 700 electrothermal atomic absorption spectrometer (AA) while gold was determined by the same technique after its extraction in methyle isobutyle ketone (MIBK). Au, Ag, Cu, Pb, Zn, Ni, Cr, Co, and Cd are present in the range of <5- 95ppb, 0.5- 11ppm, <0.5-198ppm, <0.5-3ppm, 2-36ppm, <0.5-75ppm, 22-72ppm and <0.5-4ppm respectively. It is concluded from the field and geochemical investigations that the rocks of the study area gave indications of gold, Ag and some base metals mineralization. Therefore, detailed study in regard to the economic potential and genesis of the mineralized sheared zone of the study area is needed to be carried out. [ABSTRACT FROM AUTHOR]