投稿时间：2015-12-05
修订日期：2016-09-23
网络发布日期：2017-07-04
中文摘要:仑山金矿床位于宁镇矿集区东端。成矿期分为沉积成矿期和热液成矿期，后者可进一步划分为热液Ⅰ阶段和热液Ⅱ阶段。流体包裹体研究表明，热液Ⅰ阶段石英中的气液两相流体包裹体均一温度多集中在330~366℃之间，盐度w（NaCleq）变化于4.96%~6.74%之间，热液Ⅰ阶段方解石中气液两相流体包裹体均一温度多集中在150~240℃之间，w（NaCleq）变化于0.71%~9.80%之间，成矿流体为中高温低盐度流体；热液Ⅱ阶段石英、方解石和萤石的流体包裹体均一温度变化于124~260℃，盐度w（NaCleq）变化于1%~8%之间，成矿流体为中温低盐度流体。氢、氧同位素研究表明，热液Ⅰ阶段成矿流体为岩浆流体，热液Ⅱ阶段成矿流体以大气降水占主导，但仍有少量岩浆流体。硫同位素研究表明，仑山金矿床沉积成矿期硫除来源于三叠系青龙群膏盐层外，有机质也参与了沉积成矿期中金矿的形成。热液Ⅰ阶段硫来源于沉积成岩阶段黄铁矿的活化迁移和富集，岩浆硫也提供了成矿物质。萤石Sm_Nd测年分析表明，仑山金矿床热液Ⅱ阶段成矿年龄为（93.7±3.1）Ma，推断主成矿阶段形成于晚白垩世。仑山金矿床的形成代表着长江中下游成矿带最晚期的成矿作用。
Abstract:The Lunshan gold deposit is located in the east of the Ningzhen ore concentration area. Mineralization stage can be divided into sedimentary and hydrothermal epochs. The latter is further divided into hydrothermal Ⅰ and hydrothermal Ⅱ stages. The analyses of fluid inclusions indicated that the homogenization temperatures of inclusions in quartz of hydrothermal Ⅰ stage mostly vary from 330℃ to 366℃ with the salinities w(NaCleq) varying from 4.96% to 6.74%. The homogenization temperatures of inclusions in calcite of hydrothermal Ⅰ stage vary from 150℃ to 240℃ with the salinities w(NaCleq) between 0.71% to 9.8%. The ore-forming fluid of hydrothermal Ⅰ stage was high-medium temperature and low salinity fluid. The homogenization temperatures of two phases (gas+liquid) fluid inclusions in quartz, calcite and fluorite of hydrothermal Ⅱ stage vary from 124℃ to 260℃ with salinities w(NaCleq) mostly between 1% and 8%. Hydrogen and oxygen isotopic studies suggested that the ore-forming fluid of hydrothermal Ⅰ stage was magmatic fluid, and the hydrothermal Ⅱ stage fluid was meteoric water with minor magmatic fluid. The sulfur isotope analysis using pyrites of sedimentary epoch indicated that sulfur came from the evaporate bed of the Triassic Qinglong Group with the organic matters involved in the formation of sedimentary pyrites. The sulfur of hydrothermal Ⅰ stage was from activation, migration and enrichment of sedimentary pyrites. Magmatic sulfur also supplied ore-forming materials of hydrothermal Ⅰ stage. The Sm-Nd isochron age of fluorite of hydrothermal Ⅱ stage is (93.7 ±3.1) Ma, representing the youngest age of the Lunshan gold deposit. The authors infer that the main ore-forming epoch/stage occurred during the Late Cretaceous. The formation of the Lunshan gold deposit represented the final mineralization of the Middle-Lower Yangtze River Metallogenic Belt.
keywords:geochemistry fluid inclusions stable isotopes Sm-Nd dating genesis of deposit Lunshan gold deposit
文章编号：
中图分类号：P618.51
文献标志码：
基金项目:本文得到"江苏省地质矿产局科研项目（编号：2014-KY-5）"和"国家自然科学基金（编号：41372091）"联合资助
引用文本：
陆邦成,余金杰,陈春生,王铁柱,车林睿,陆振裕,尹灵强.2017.江苏仑山金矿床流体包裹体、稳定同位素和成矿年代学研究[J].矿床地质,36(3):675~690LU BangCheng,YU JinJie,CHEN ChunSheng,WANG TieZhu,CHE LinRui,LU ZhenYu,YIN LingQiang.2017.Study of fluid inclusions, stable isotopes and geochronology of Lunshan gold deposit, Jiangsu Province[J].Mineral Deposits36(3):675~690
图/表
