湘西桃源县西安钨金矿床褶皱构造的发现及控矿意义

湖南桃源县西安钨金矿床位于湘西矿化集中区西安金锑钨成矿带的中部,距沃溪钨锑金大型矿床约15km,是湖南重要的钨金矿床。前人研究注意到该矿区内含矿地层及断裂构造叠加对矿床形成的控制作用。文章通过矿区地质研究和地球物理测量,结合区域地质演化和对前人资料的分析,发现该矿区还存在重要的褶皱构造。对该矿床的形成和分布提出了新的认识,该矿床的形成除受地层和断裂构造控制之外,还受到褶皱构造的明显控制,提出了:有利地层和缓倾斜EW向层间滑动断裂带叠加控制了矿化带的形成和分布,高角度NE向断裂是重要的导矿构造,褶皱构造的叠加控制了矿床的形成和分布,次级褶皱尤其是背斜构造的叠加则控制了矿体的形成和分布,该矿床的成矿有利地段是地层和层间滑动断裂带之上叠加了褶皱构造的地段。

Discovery of fold structure in Xi'an W-Au deposit of Taoyuan County, western Hunan, and its ore-controlling significance

Located at the center of the Xi'an Au-Sb-W mineral belt 15 km away from the well-known Woxi W-Sb-Au large-sized deposit, the Xi'an ore deposit is an important W-Au deposit in western Hunan. Previous researchers noticed the controlling role of the superposition of the ore-bearing strata and faults in the formation of the W-Au deposit. Based on geological investigation and geophysical survey in the ore district as well as an analysis of the regional geological evolutionary history and the data available, the authors detected in this study the existence of an important fold core in the Xi'an W-Au deposit. A new opinion is thus put forward that, apart from ore-bearing strata and faults, this important fold structure controls the mineralization of the Xi'an W-Au deposit. The favorable strata and faults control the formation of the W-Au ore belt, the fold controls the formation and distribution of the ore deposit, and the anticline core of the second-order fold controls the distribution of the ore bodies. On such a basis, it is held that the most promising target for new potential mineralization is the core of anticline, to which previous researchers did not seem to pay sufficient attention.