CAJ | 학술논문

云南金顶铅锌矿是目前中国最大的铅锌矿，也是铅锌矿金属储量超过千万吨的世界级超大型矿床之一。对该矿床主矿化期和矿化后期方解石进行了系统的碳、氧、锶同位素分析，结果表明，主矿化期脉状方解石碳同位素变化范围大(δ13C-23.0‰～-2.6‰)，显示有机沉积物与海相碳酸盐岩混合碳的特征，氧同位素相对集中(δ18O 22.1‰～23.5‰)，类似于沉积岩，Sr含量较高(Sr 163～1920μg/g)，富放射成因锶(87Sr/86Sr 0.709860～0.710362)；而矿化后期结核状方解石碳同位素分布集中(δ13C -7.0‰～-6.2‰)，氧同位素(δ18O 20.2‰～22.4‰)类似于沉积岩，在150～200℃时，据公式1000 ln α方解石-水=4.01×106/T2-4.66×103/T+1.71计算，与矿化后期结核状方解石平衡的流体的δ18O 流体介于7.1‰～12.7‰之间，此外，结核状方解石 Sr 含量较高(Sr 240～817μg/g)，富放射成因 Sr (87Sr/86Sr 0.710235～0.710347)。金属硫化物铅同位素(206Pb/204Pb 18.373～18.452,207Pb/204Pb 15.605～15.668,208Pb/204Pb 38.524～38.726)在铅演化图解上位于造山带演化线与上地壳演化线之间，变化范围类似于兰坪盆地上地壳沉积岩系和喜马拉雅期岩浆岩。综合分析认为，金顶铅锌矿至少存在两期热液矿化事件，主矿化期成矿流体主要来源于富含有机质的上三叠统三合洞组灰岩中的地层水，可能有深源组分的加入；矿化后期成矿流体系大气降水。成矿流体在盆地中迁移时与围岩(含膏岩)发生了强烈的水岩反应。成矿金属可能来源于上三叠统三合洞组灰岩和喜马拉雅期岩浆岩。
운남금정연자광시목전중국최대적연자광，야시연자광금속저량초과천만둔적세계급초대형광상지일。대해광상주광화기화광화후기방해석진행료계통적탄、양、송동위소분석，결과표명，주광화기맥상방해석탄동위소변화범위대(δ13C-23.0‰～-2.6‰)，현시유궤침적물여해상탄산염암혼합탄적특정，양동위소상대집중(δ18O 22.1‰～23.5‰)，유사우침적암，Sr함량교고(Sr 163～1920μg/g)，부방사성인송(87Sr/86Sr 0.709860～0.710362)；이광화후기결핵상방해석탄동위소분포집중(δ13C -7.0‰～-6.2‰)，양동위소(δ18O 20.2‰～22.4‰)유사우침적암，재150～200℃시，거공식1000 ln α방해석-수=4.01×106/T2-4.66×103/T+1.71계산，여광화후기결핵상방해석평형적류체적δ18O 류체개우7.1‰～12.7‰지간，차외，결핵상방해석 Sr 함량교고(Sr 240～817μg/g)，부방사성인 Sr (87Sr/86Sr 0.710235～0.710347)。금속류화물연동위소(206Pb/204Pb 18.373～18.452,207Pb/204Pb 15.605～15.668,208Pb/204Pb 38.524～38.726)재연연화도해상위우조산대연화선여상지각연화선지간，변화범위유사우란평분지상지각침적암계화희마랍아기암장암。종합분석인위，금정연자광지소존재량기열액광화사건，주광화기성광류체주요래원우부함유궤질적상삼첩통삼합동조회암중적지층수，가능유심원조분적가입；광화후기성광류체계대기강수。성광류체재분지중천이시여위암(함고암)발생료강렬적수암반응。성광금속가능래원우상삼첩통삼합동조회암화희마랍아기암장암。
The Jinding Zn-Pb deposit in Yunnan Province, is the largest Zn-Pb deposit in China, and one of the world-class super-large deposits with Zn+Pb reserves more than 10 Mt. A systematic study of carbon, oxygen and strontium isotopes has been carried out on main mineralization vein calcites and post-mineralization nodule calcites. The main mineralization vein calcites show a large variation ofδ13C (-23.0‰--2.6‰), indicating mixed carbon source of sedimentary organics and marine carbonates, with high δ18O (22.1‰ - 23.5‰) similar to the sediments, and high Sr contents (163 - 1920 μg/g), as well as 87Sr/86Sr (0.709860 - 0.710362). The post-mineralization nodule calcites have homogeneous δ13C (-7.0‰ - -6.2‰) and δ18O (20.2‰ - 22.4‰), high contents of Sr (240 - 817 μg/g) and 87Sr/86Sr (0.710235 - 0.710347). Besides, the calculated δ18O of the ore-forming fluid equilibrated with the post-mineralization nodule calcites, range from 7.1‰ to 12.7‰ at 150 -200℃by the equation 1000 lnαcalcite-water=4.01×106/T2- 4.66×103/T+1.71 (Zheng, 1991). Pb isotopes in sulfides (206Pb/204Pb 18.373 - 18.452, 207Pb/204Pb 15.605 - 15.668, 208Pb/204Pb 38.524 - 38.726) plot between the line of orogenic Pb and the line of upper crustal Pb in Pb evolution diagram (Zartman and Doe, 1981), consistent with the Himalayan magmatisms and partially overlapping with the upper crustal sedimentary rocks in the Lanping basin. These indicate that there were at least two episodes of hydrothermal mineralization in Jinding. The ore-forming fluid at the main mineralization stage might be the formation water originating from organic-rich limestones of the Upper Triassic Sanhedong Formation, apart from some involvement of deep-sourced components, whereas the ore-forming fluid at the post-mineralization stage is dominated by meteoric water. During migrating in the basin, the ore-forming fluids reacted with wall rocks and acquired high contents of radiogenic 87Sr. Metals were likely provided by the Upper Triassic Sanhedong Formation limestones and Himalayan igneous rocks.