贵州南部“半边街式”铅锌矿床地质特征及其成因探讨

贵州省南部地区是全国重要的汞、锑资源分布区。2000年由于产于上泥盆统中铅锌矿的陆续发现,贵州省地矿局启动了以铅锌资源评价和成矿规律研究为主的地质工作,目标是总结铅锌矿产出的地质特征和成矿规律。通过三年的研究认为,该区处扬子准地台、华南褶皱带和右江造山带交汇部位,受晚古生代初期发生的陆内裂谷活动影响,产生了一个与桂中台陷相连的大型沉积凹陷区—黔南台陷沉积区,形成了巨厚碳酸盐和碎屑岩沉积,产生了与裂陷盆地边缘同沉积断层活动有关的低温成矿作用,造成了在晚泥盆纪以前的地层中汞、锑、砷、金、铅锌等矿床沿同沉积断层密集分布。本文通过矿床特征总结和矿床成因探讨,建立了准同生沉积成矿作用模式,旨在为该区寻找这类矿床提供参考和借鉴作用。

Geological Characteristics and Genesis of the Banbianjie Type Lead-Zinc Deposits in Southern Guizhou Province

Southern Guizhou is an important area for mercury and antimony resources in China. As abundant Upper Devonian lead-zinc deposits had been discovered one after another, the Guizhou Bureau of Geology and Mineral Exploration & Development started in 2000 the geological work for appraising lead-zinc resources and studying ore-forming regularity. The study area, i.e., Huangsi-Jiangzhou of southern Guizhou, is located at the intersection position of the Yangtze paraplatform, the South China fold system and the Youjiang orogenic belt. Affected by the early Late Paleozoic inland rifting, southern Guizhou became a large depositional basin called Qiannan platform collapse sedimentary area, which was connected with the Guizhong platform collapse and formed thick and extensive sediments of carbonates and clastic rocks. The epithermal mineralization related to the syndepositional faulting activity along the margin of the Qiannan platform led to the dense distribution of mercury, antimony, arsenic, gold and lead-zinc deposits along the syndepositional faults in the pre-Upper Devonian strata. Based on the discussion on the geological characteristics and genesis of lead-zinc deposits in southern Guizhou Province, the authors have established a para-syndepositional ore-forming model for Banbianjie-type deposits to help the prospecting for this kind of ore deposits in this area.