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河南瓦房铅锌矿床位于华北克拉通南缘熊耳山—外方山矿集区,矿体赋存于熊耳群鸡蛋坪组上段(Chj3)的地层中,矿石矿物有黄铁矿、方铅矿、闪锌矿和少量黄铜矿、赤铁矿、褐铁矿。该矿床热液成矿过程划分为3个阶段:石英-黄铁矿阶段(早阶段),石英-多金属阶段(中阶段),石英-碳酸盐脉阶段(晚阶段)。矿石中石英和方解石中捕获的原生包裹体类型有NaCl-H2O型两相、NaCl-CO2-H2O型三相和纯气相。气液两相包裹体3个阶段均一温度范围分别为150~260、150~230和110~160℃,3个阶段盐度(w(NaCl))平均值分别为12.22%、8.55%和6.29%。中阶段方解石的δ13 CVPDB平均值为-7.34‰,δ18 OSMOM平均值为15.56‰;晚阶段方解石的δ13 CVPDB平均值为-3.05‰,δ18 OSMOW平均值为2.21‰。早阶段硫化物的δ34S值为2.747‰~7.737‰,中阶段硫化物的δ34S值为-11.187‰~7.286‰。认为早中阶段成矿流体为变质流体,与中生代扬子克拉通和华北克拉通发生陆陆碰撞诱发中—新元古代时期的俯冲板片变质脱水有关,成矿晚阶段流体有大气降水的混入。硫同位素表明硫来源于中—新元古代的沉积地层,是海相硫酸盐的还原产物,在晚阶段,由于大气降水的混入导致δ34S出现负值。瓦房铅锌矿床地质特征、成矿流体特征与造山型矿床相似,因此,瓦房铅锌矿床属于造山型铅锌矿床。
The Wafang lead-zinc deposit in Henan Province is located in the Xierershan-Waifangshan ore concentration area on the southern margin of the North China Craton, and the orebodies occur in the strata of the upper part of the Eggping Formation of the Xiong’er Group (Chj3). The ore minerals include pyrite, galena , Sphalerite and a small amount of chalcopyrite, hematite, limonite. The hydrothermal mineralization process is divided into three stages: quartz-pyrite stage (early stage), quartz-polymetallic stage (middle stage) and quartz-carbonate pulse stage (late stage). The types of primary inclusions captured in quartz and calcite in ore include NaCl-H2O two-phase, NaCl-CO2-H2O three-phase and pure gas phase. The homogenization temperature ranges of three phases of gas-liquid two-phase inclusions are 150-260,150-230 and 110-160 ℃, respectively. The average values of salinity (w (NaCl)) in three phases are 12.22%, 8.55% and 6.29% . The average δ13 CVPDB of middle calcite is -7.34 ‰ and the average of δ18 OSMOM is 15.56 ‰. The average δ13 CVPDB of calcite in late stage is -3.05 ‰ and the average of δ18 OSMOW is 2.21 ‰. The δ34S value of sulfides in the early stage ranged from 2.747 ‰ to 7.737 ‰, and the δ34S value in the mid-stage sulfides ranged from -11.187 ‰ to 7.286 ‰. It is considered that the ore-forming fluids in the early and middle stages are metamorphic fluids and are related to metamorphic and dehydrated subducting slabs induced by land-continent collision in the Mesozoic Yangtze Craton and North China Craton. Sulfur isotopes indicate that sulfur is derived from Meso-Neoproterozoic sedimentary formations and is a reduction product of marine sulfate. In the late stage, δ34S shows a negative value due to the mixing of atmospheric precipitation. The Wafang lead-zinc deposit has similar geological features and ore-forming fluid characteristics as orogenic deposits. Therefore, the Wafang lead-zinc deposit belongs to the orogenic lead-zinc deposit.