南京大学学报（自然科学版）2018，Vol.54Issue(2)：366-385,383,21.DOI:10.13232/j.cnki.jnju.2018.02.011
湘东北地区栗山铅锌铜多金属矿床的成因探讨:来自矿床地质、矿物学和硫同位素的证据
Genesis of the Lishan Pb-Zn-Cu polymetallic deposit in northeastern Hunan province:evidences from the geology,mineralogy and sulfur isotopes
摘要
Abstract
The northeastern Hunan province is located at the central segment of the Jiangnan Orogen known as an economically important Au-Sb-W-Cu polymetallic metallogenic belt.Recently,several Co,Cu,Pb-Zn polymetallic deposits were discovered in northeastern Hunan Province,and they all have a close spatial relationship with the Yan-shanian plutons.Among these deposits,the Lishan Pb-Zn-Cu polymetallic deposit occurs within the Mufushan pluton and its contact zone,with orebodies hosted within altered fracture zones.Based on the detailed field investigation and microscopic observation,the Lishan Pb-Zn-Cu polymetallic mineralization can be divided into two epochs:hydrother-mal mineralization and supergene enrichment.Furthermore,hydrothermalism can further be subdivided into four stages:coarse quartz+fluorite+chlorite(ChlⅠ)+minor pyrite+chalcopyrite stage(I),quartz+fluorite+chlorite (ChlⅡ)+chalcopyrite+pyrite stage(Ⅱ),quartz+fluorite+chlorite(ChlⅢ)+sphalerite+chalcopyrite+galena stage (Ⅲ),and fine-grained quartz+minor pyrite+chalcopyrite stage(Ⅳ),from early to late.The EPMA analyses show that ChlⅠbelongs to ripidolite,and that ChlⅡand ChlⅢare dominated by daphnite and brunsvigite.The empirical geothermometers of chlorite yield temperatures of 239 ℃~280 ℃(av.255 ℃),221 ℃~261 ℃(av.244 ℃)and 212 ℃~238 ℃(av.231 ℃)for ChlⅠ,ChlⅡand ChlⅢ,respectively,showing a decreasing trend.The estimated oxygen fugacities lgf(O2)and sulfur fugacities lgf(S2)are -39.90~-34.77 and 0.22~8.41,-42.29~-37.51 and-3.25~4.25,and -43.71~-39.08 and -2.88~1.47 for ChlⅠ,ChlⅡand ChlⅢ,respectively,suggesting an environment of low oxygen fugacity and low sulfur fugacity.Sphalerite and galena yield δ34S values of -4.7‰ to 1.5‰,suggesting a predominant magmatic sulfur origin.Integrating the geological,mineralogical and sulfur isotopic data documented in this study,as well as the contrast with typical Pb-Zn deposits within the Qin-Hang metallogenic belt,we propose that the Lishan Pb-Zn-Cu polymetallic deposit formed from a hydrothermal system related to the Mufushan pluton,and is of medium-temperature hydrothermal fracture filling type.关键词
中温热液充填交代型矿床/栗山铅锌铜多金属矿床/幕阜山岩体/湘东北地区Key words
Medium-temperature hydrothermal fracture filling type/Lishan Pb-Zn-Cu polymetallic deposit/Mufushan pluton/northeastern Hunan province分类
天文与地球科学引用本文复制引用
郭飞,王智琳,许德如,董国军,宁钧陶,王展,邓腾,于得水,崔宇..湘东北地区栗山铅锌铜多金属矿床的成因探讨:来自矿床地质、矿物学和硫同位素的证据[J].南京大学学报（自然科学版）,2018,54(2):366-385,383,21.基金项目
国家自然科学基金(41672077,41302049),科技部国家重点研发计划(2016YFC0600401),湖南省自然科学基金(2016JJ3143) （41672077,41302049）
