摘要点击次数: 8326 全文下载次数: 6295 点此下载全文
中文摘要:通过对长江中下游成矿带的系统考察和对前人资料的阅读和研究，聚焦铜陵矿集区，初步提出了一个可以涵盖不同类型矿床的矿床模型。该模型表达为：在早白垩世高钾钙碱性花岗岩侵位过程中，通过岩浆的分馏演化，在岩体隆起部位及其内外接触带形成斑岩 矽卡岩型矿床，由于广泛发育石炭纪至三叠纪碳酸盐岩，钙质和镁质矽卡岩型矿床是最主要的矿床类型。作为斑岩 矽卡岩型矿床系统的一部分，在斑岩 矽卡岩铜金钼矿床外围分布有矽卡岩铜金矿床、脉状金矿床以及脉状铅锌银矿床。长江中下游地区在三叠纪曾作为大别—苏鲁造山带的前陆盆地，在后碰撞时期出现了大量滑覆构造和扩容空间，它们在不整合界面处十分发育。因此，在成矿过程中不仅形成了像新桥那样的厚大矿体，而且在位于不整合界面附近的矽卡岩往往退化蚀变成为具有典型层纹状和曲卷状构造的退化蚀变岩和矿石，甚至沿一些层位交代形成了层控矽卡岩型或Manto型矿体。此外，还提出了运用该模型开展勘查评价的建议
Abstract:According to field investigations of major ore deposits along the Middle Lower Yangtze Valley metallogenic belt and a detailed study of the data available, the authors put forward a mineral deposit model based on the Tongling ore district, the largest ore cluster in the belt. The porphyry skarn Cu-Au-Mo ore bodies developed around the roof pendants of the high potash calcalkaline granitoids have experienced strong fractionation. Since there are extensively distributed Carboniferous Permian carbonates, both calcic and magnisian skarn deposits have most important economic significance. As components of the porphyry skarn system, the skarn and vein like gold deposits and veinlike Pb-Zn-Ag deposits are distributed outward gradually from the intrusion and the porphyry skarn Cu-Au-Mo ore deposits. Because the Middle Lower Yangtze Valley belt was a foreland basin during the collision between the South China massif and the North China craton and subsequently a depression belt during the post collision with a lot of decollement and detachment faults, especially along the discontinuity boundary which occupied a large space, the large ore bodies must have been formed along the large space, such as the major ore body in the Xinqiao S-Cu-Au polymetallic mine. The strong retrograde alteration, consisting of actinolite tremolite chlorite epidote or serpentine Mg chloritetalctremolite with typical wrigglite and laminated structures along either fractures or discordant boundary, replaced the skarn at the contact with the granitoid intrusion. There are also a lot of Manto or stratabound skarn ore bodies replacing some carbonate layers of different ages. This paper also indicates the correct utilization of the model together with some types of geochemical and geophysical technologies for further prospecting in similar tectonic settings.
keywords:geology mineral deposit model, porphyry skarn deposit, Tongling ore district, Middle Lower Yangtze Valley metallogenic belt
MAO JingWen,SHAO YongJun,XIE GuiQing,ZHANG JianDong,CHEN YuChuan.2009.Mineral deposit model for porphyry skarn polymetallic copper deposits in Tongling ore dense district of Middle Lower Yangtze Valley metallogenic belt[J].Mineral Deposits28(2):109~119