山东沂南金矿田成矿构造系统和构造控矿规律

Metallogenic Tectonic System of Yinan Au-Cu Deposit,Shandong Province

通过成矿构造研究并辅以多种找矿手段综合分析,以期取得危机矿山找矿的新突破。通过矿区构造地质调查、构造地球化学测量、构造蚀变带填图和以往勘探资料系统整理编图,厘定了沂南金矿田区域性断裂构造(入字型构造)与岩体侵位构造(仌字型构造)复合成矿构造系统,阐述了复合成矿构造系统的基本要素、特征和控矿作用,系统地总结了矿田构造控矿规律。提出:由金场岩体、铜井岩体、银山庄岩体构成了门字形的区隔化空间,控制了金场矿区和铜井矿区富矿段的产出;中酸性岩柱、岩颈及近接触带的寒武系和新元古界多层次的层间滑动带和岩床构造,控制了多层次金铜矿体的产出,但在远离接触带的部位,高角度次级的NNE、NWW-NW向断裂,控制了构造蚀变岩型的金铜矿体;堆金山矿段不是典型的斑岩型金矿,而是产在玢岩体中受NWW-NW向断裂控制的构造蚀变岩型金矿;土门群和泰山群不整合面亦是重要的控矿界面,值得下一步找矿的重视;矿田矿化深度东深西浅,南深北浅,与基底泰山群顶界的埋深具有明显相关性。

Metallogenic structure investigation is an important method in prospecting of crisis mines. The metallogenic tectonic system of the Yinan Au-Cu deposit is constructed on the basis of geological and tectonic geochernical survey, tectonic alteration zone mapping and compilation of the previous exploration data. It is evident that the Jinchang, Tongjing and Yinshanzhuang plutons control the distribution of the rich ores in the Jinchang and Tongjing mining districts; the multi-layered sliding belts in the Upper Proterozoic and Cambrian near the contact zone with the intermediate and acidic intrusions control the stratiform Au-Cu ore bodies; whereas the secondary high-angle NNE trending and NWW-NW trending faults far away from the contact zone are hosts of the tectonic altered rock type gold copper ores. The Duijinshan section is not typical porphyry gold mineralization, but the structural altered rock type gold mineralization located inside of the porphyry and controlled by the NWW-NW trending fractures. The unconformity between the Tumen Group and Taishan Group is also an important ore-controlling interface and worthy attention of future prospecting. The depth of mineralization in the area is obviously related to the buried depth of the Taishan Group.