Fluid inclusion study of the Wuziqilong Cu deposit in the Zijinshan ore field, Fujian Province

The Wuziqilong intrusion-related hypothermal Cu deposit locates in the northeast of the Zijinshan ore field. It is hosted by Zijinshan complex consisting of mainly Yanshanian biotite monzogranites. Disseminations, veinlets and stockworks are the main ore structures. Four stage veins can be distinguished from their mineralogical paragenesis and crosscutting relationships. The first stage is quartz feldspar vein system preserved in the sericite-dickite-quartz zone. The second and third are quartz-bornite-chalcopyritedigenite-pyrite +/- covellite and quartz-covellite-pyrite polymetallic sulfide stockworks, respectively, observed in sericitization-dickitization-silicification zone which is overprinted by alunitization-silicification. The stage 4 quartz gypsum calcite veinlets occur in alunitization-silificication zone. Stage 1 minerals contain CO2-rich and aqueous fluid inclusions with variable vapor/liquid ratios, which are homogenized at 362 similar to 570 degrees C, with salinity of 4% similar to 19.92% NaCleqv. In addition to the fluid inclusions observed in stage I crystals, daughter mineral-bearing fluid inclusions can be also observed in stage 2 minerals. These fluid inclusions are homogenized at 306 similar to 390 degrees C, with salinity of 0.35% similar to 13.94% NaCleqv (daughter minerals are not included in estimation). Stage 3 minerals have both vapor-rich and liquid-rich two-phase aqueous fluid inclusions that yield homogenization temperature of 233 similar to 308 degrees C and salinity of 0.18% similar to 14.67% NaClegv. Stage 4 minerals only contain liquid-rich aqueous fluid inclusions homogenized at 132 similar to 230 degrees C, with salinity of 0.88% similar to 6.16% NaClegv. Hence it can be drawn out that the fluids forming the Wuziqilong deposit evolved from initially-magmatic hypothermal NaCl-CO2-H2O system to finally-meteoric epithemial NaCl-H2O system, and that during the evolution fluid boiling occurred, volatiles such as CO2 escaped and metallic sulfides precipitated, followed by input of circulating meteoric water.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000292712600016&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701GeologySCI(E)中文核心期刊要目总览(PKU)中国科技核心期刊(ISTIC)中国科学引文数据库(CSCD)235,SI1425-14382