Ore‐forming Material Sources of Liaotun Gold Deposit in Bama County, Northwestern Guangxi

Progressive crushing 40Ar/39Ar dating of a gold-bearing quartz vein from the Liaotun Carlin-type gold deposit, Guangxi, southern China

“…The fault-bound Liaotun gold deposit, in Bama County, Northwest Guangxi, is a medium-sized Carlin-type gold deposit, which is located on the southwestern margin of the isolated Longtian carbonate platform (Fig. 1 b) 18 , 30 , 46 . The exposed sedimentary rocks in the platform are mainly limestone, intercalated with dolomite of the Carboniferous Du’an Formation (C 1-2 d ) and Permian sponge reef limestone (P bls ).…”

“…Among them, the NW-trending faults F1 and F2 are syn-sedimentary faults, while the NW-trending F4 and the EW-trending F5, F6, F9 faults are ore-bearing structures, hosting the ore bodies labelled I, III, IV, and V, respectively (Fig. 1 c) 18 , 46 . Late Yanshanian (97–95 Ma) quartz porphyry veins intruded Carboniferous limestone and Triassic sandstone along an ENE- to NE-trending fault across the Longtian dome 18 , 30 .…”

“…Hydrothermal alteration associated with gold mineralization in the deposit includes silicification, pyritization, arsenopyritization, (de)carbonation, clayization and sulfidization. The occurrence, textures, and mineral assemblages of the ores at Liaotun indicate that the hydrothermal alteration associated with gold mineralization in the deposit can be divided into four stages: (1) decarbonation + silicification stage; (2) quartz + pyrite + arsenopyrite stage; (3) quartz + stibnite stage; (4) quartz + calcite + clayization stage 18 , 46 .…”

“…The smaller III and V ore bodies are controlled by EW-trending vertical F5 and F6 faults. Body III are 230 m long and 7.20 m thick with an average gold grade of 7.33 g/t, and orebody V is 194 m long, 1.16 m thick and has an average gold grade of 0.34 g/t Au 18 , 46 . Orebody V is hosted in siltstone, mudstone and thick-bedded sandstone in the second member of middle Triassic Baifeng Formation.…”