柴北缘青龙沟金矿床黄铁矿热电性与原位微量元素特征及其深部找矿意义OA

The Qinglonggou gold deposit is located in the Tanjian Mountain giant gold field along the northern margin of the Qaidam Basin.Orebodies are hosted in Mesoproterozoic Wandonggou Group phyllite and marble and are distinctly controlled by structures.Pyrite is the principal gold-bearing mineral,and its thermoelectric properties combined with in situ trace element compositions provide important constraints on ore-forming fluids and deposit genesis.Ore-stage pyrite samples from different depths of drill cores along exploration line 51 in the No.II ore belt were analyzed for thermoelectric characteristics and trace elements.Pyrite from different depths is predominantly of mixed P-N type,with thermoelectric coefficients mainly ranging from-250 μV/℃to 0.Formation temperatures cluster at 50 to 150℃and 350 to 525℃.Mineralizing fluids are enriched in As,Au,Cu,and Sb.Most pyrite samples show Co/Ni ratios of 0.1 to 1,whereas a minor proportion of ratios>1.Deep-level pyrite contains mantle-derived platinum-group elements(Pd,Pt).The phenomena described above indicate that the Qinglonggou Gold Deposit exhibits characteristics of both low-temperature and medium-to-high-temperature mineralization,with elemental features analogous to those reported in previous studies on Carlin-type gold deposits.Mineralization was influenced by both hydrothermal and sedimentary processes,with possible incorporation of mantle-derived materials into the ore-forming fluids.Overall,the Qinglonggou deposit is interpreted as a Carlin-orogenic composite-type gold deposit.Shallow mineralization is dominated by medium-to low-temperature hydrothermal processes influenced by sedimentary metamorphism,whereas deep mineralization reflects the combined effects of sedimentary metamorphism and high-temperature hydrothermal activity,recording multi-stage mineralization with mantle material input.Exploration should focus on structur-ally altered zones characterized by As-Au-Cu-Sb assemblages and P-N-type pyrite thermoelectric signatures.