云南东川地区播卡矿田沉积环境初探

Discussion of sedimentary environment of Boka mine field

在收集有关东川及邻区区域地质、矿产和物化探资料的基础上,探讨播卡矿田成矿地质背景及发展演化史。通过岩石建造,采用稀土元素分析的方法,结合区域岩相古地理研究成果,分析播卡矿田在中昆阳期处于大陆边缘沉积环境,因民期播卡矿田为强烈断陷阶段,落雪期播卡矿田进入了坳陷阶段,黑山期为闭塞滞流海湾沉积环境,总体表现为海侵正向层序,形成了紫-灰-黑建造系列。

On the basis of data collection of regional geological, mineral and physical-chemical exploration in Dongchuan and its adjacent areas, the ore-forming geological background and evolution history of Boka mine field were discussed. Through analysis of rock formation, rare earth elements and regional lithofacies and paleogeographic results, the authors revealed the environment of Boka mine field was of sedimentary environment of continental margin, strongly fault depression, down-warped and occlusive stagnant flow embayment respectively, corresponding to middle Kunyun period, Yinmin period, Luoxue period and Heishan period. The change of aggregate environment was a positive marine transgression sequence, that was purple-gray-black formation series.