Characteristics of tungsten (scheelite) mineralization in the Tai Soong – Ban O area, Pia Oac region, Cao Bang province
Abstract
This paper presents the study results of scheelite mineralization in the Tai Soong - Ban O area, Pia Oac, Cao Bang Province, based on field mapping, core logging and laboratory analyses. The Tai Soong tungsten deposit occurs within carbonate interbedded with clastic sedimentary rocks of the Coc Xo Formation (D1-D2ecx), at the southwestern margin of the Pia Oac intrusion. Detailed geological mapping and resource evaluation have identified four hidden lens-shaped scheelite ore bodies at depths from 25 to 225 meters, hosted in a skarn alteration zone formed at the contact between carbonate rocks of the Coc Xo Formation and granitic intrusions of the Pia Oac complex. These ore bodies have the lengths of 140-580 meters, an average thickness of 1-2 meters and WO₃ grades ranging from 0.05% to 1.65%. Scheelite is the primary ore mineral, commonly associated with pyrrhotite and chalcopyrite. The ores exhibit disseminated and pocket textures, with anhedral to subhedral granular crystals. Scheelite accumulation in the study area is closely related to metasomatic processes at the granite-carbonate contact. Hydrothermal alterations asociated with the mineralization include albitization, skarn metasomatism, actinolitization, tremolitization and epidotization. Magmatic activity and the NW-SE trending fault played a key role in channeling and controlling ore-bearing fluids. These findings contribute to a better understanding of the skarn-type tungsten mineralization mechanism in the Pia Oac area and provide a scientific basis for further exploration of scheelite deposits in the region.
