%0 Journal Article
%T 滇东北毛坪铅锌矿床的成矿时代：闪锌矿Rb-Sr定年
%A 沈战武
%A 金灿海
%A 代堰锫
%A 张玙
%A 张海
%J 高校地质学报
%D 2016
%X 毛坪铅锌矿床是滇东北地区代表性矿床之一，目前尚缺乏精确的成矿年代学数据。该文对选自块状铅锌矿石的4件 闪锌矿单矿物样品进行了Rb-Sr同位素定年，获得等时线年龄为321.7±5.8 Ma（MSWD=1.5），表明毛坪铅锌矿床的主成矿 作用发生于石炭纪。此外，闪锌矿87Sr/86Sr初始值为0.712166±0.000017，低于大陆地壳87Sr/86Sr平均值（0.719） 且高于地幔 Sr初始值（0.707），暗示成矿物质主要来源于大陆地壳并混有少量地幔物质。综合前人研究成果，作者认为毛坪铅锌矿属 后生矿床，与晚二叠世峨眉山大火成岩省玄武岩浆活动无成因联系，类似于典型的MVT矿床，且滇东北地区可能发育多期 铅锌矿化作用。</br>The Maoping Pb-Zn deposit is a typical ore deposit in the northeastern Yunnan province. However, there is no precise geochronological data to date. This research performed Rb-Sr isotopic dating on four sphalerite separated from the Maoping deposit, which yielded isochron age of 321.7 ± 5.8 Ma (MSWD=1.5), indicating that the mineralization age of the Maoping deposit was Carboniferous. Moreover, the 87Sr/86Sr ratio of sphalerites is determined to be 0.712166 ± 0.000017. This result is lower than that of continental crust (0.719) and higher than mantle (0.707), implying that the ore-forming metals were derived from continental crust with a minor amount of mantle-derived materials. Combining with the previous studies, we propose that the Maoping deposit is an epigenetic deposit similar to the typical MVT Pb-Zn deposits and its mineralization has no link with Permian Emeishan flood basalts. Moreover, we also suggest that multi-stage Pb-Zn mineralization most likely occurred in the northeastern Yunnan province.
%K Rb-Sr同位素&lt
%K /br&gt
%K 成矿时代
%U http://geology.nju.edu.cn/CN/abstract/abstract9766.shtml