GOLD MINERALIZATION IN NORTHERN AREAS OF PAKISTAN

Northern Areas of Pakistan have a diverse geological environment and a complex history of crustal evolution. In these areas the Kohistan-Ladakh island arc is bounded tectonically to the north by Shyok Suture Zone and to the south by Indus Suture Zone. Karakoram block is located to the north of the Shyok Suture Zone whereas; Indian plate is located to the south of the Indus Suture Zone. These areas hold potential for economic minerals, precious stones and metals including gold. Various types of gold deposits are reported from Pakistan including porphyry copper and gold deposits at Rekodeq, the Awireth-Krinj gold deposits associated with sulphide mineralization in Chitral area, placer gold along the Indus River and vein type of gold deposits in Partsan area Chitral. In this study, gold mineralization is studied in Machalu and Ranthak areas near Skardu and Astor Valley and its surrounding areas. The Machalu and Ranthak are situated near the Shyok suture while the mineralization site near Astor is located near the Indus suture zone. Using image spectroscopy and multispectral (LANDSAT, ASTER and Geoeye) remote sensing techniques mineral alteration zones are identified. The alteration zones are five to ten meters wide. These alteration zones are associated with sulphide mineralization in quartz veins in volcanic, metavolcanic and dioritic rocks. Dominant minerals in the alteration zone include malachite, azurite, pyrite and chalcopyrite. Ninety samples were collected and analyzed for gold concentrations. Our analyses show promising results and gold concentration of up to 90 ppm was found in one of these sites. Further work is in process to evaluate economic feasibility of these sites and to locate more mineralization zones.