Abstract:

The Bien Dong-Quy Son area, Bac Giang province is considered as a high potential area of copper deposits such as the Dong Bua, Khuon Muoi, Goc Sau, Giao Liem, Trai Bau copper occurrences. Based on synthesizing, geological processing data, analysis and complement of the 100 thin sections, 150 thick sections, 20 scanning electron microscope and 10 ICP - MS samples, results show that the copper mineralization has fomed from medium-low hydrothermal origin, and characteristics by tetrahedrite- chalcosine-bornite-tenantite-chalcopyrite association. Research results show that the ore mineral composition is relatively complex, primary ore minerals include tetrahedrite, tennantite, bornite, chalcosine, chalcopyrite, native copper, pyrite, galenite, sphalerite, electrum, and native gold. Secondary ore minerals include malachite, a zurite, covelin, cuprite, and limonite. The hydrothermal changes encountered in the study area include quartzization, chloritization, dolomitization, sericitization. Copper ore in the region is distributed mainly in tectonic fracture zones from the sub-latitudes to the northeast - southwest directions and it is controlled by two factors as the arc-shaped fault and sub-latitude to northeast - southwest fault systems, they plays the role of ore distribu tion and scirculation channel. The litho-stratigraphic element is the limestone-bearing terrigenous sedimentary rocks belonging to the middle and upper sub-formations of the Mau Son Formation.