Mineralogical geochemical characteristics and resource potential of copper ore in the Lang Chanh area, Thanh Hoa Province

Abstract

Lang Chanh area, Thanh Hoa province, is considered a high potential area of copper deposits such as the Lang Van, Lang Trang, and Lang Hac copper occurrences. Based on published data and our supplement analyses of 5 thin sections, 4 thick sections, and 2 scanning electron microscope samples, we found that the copper mineralization had formed from hydrothermal activities at moderate-high temperature, belonging to quartz-copper-sulfur-polymetallic, magnetite-sulfur-copper (Lang Van, Lang Trang), and quartz-sulfur-copper (Lang Hac) mineral deposit types. The mineral composition was quite simple: pyrite, chalcopyrite, pyrrhotite, covelline, galenite, sphalerite, melnicovite, gothite, and magnetite. Non-ore minerals were quartz, rarely chlorite, siderite, sphene, garnet, and calcite. The copper contents in orebodies varied from low to high values, with average contents ranging from 0.20 to 7.45 (%). In the Lang Chanh area, 17 copper ore bodies were discovered and distributed in 9 mineralized zones, belonging to three areas of Lang Van, Lang Hac, Lang Trang, and some gabbro boulders the Nui Chua complex with disseminated chalcopyrite. Using linear calculation method for metallization parameters and Huvo methods to estimate gold resources in the study area, resulted in 1.44 million tons of Cu-metal. These results provided an overview of the prospect of copper resources, serving as a basis for determining the Cu prospective areas in Lang Chanh, Thanh Hoa province.