【摘要】 对海沟金矿的断层、节理进行野外和井下研究,应用赤平投影方法对节理产状进行统计与分析,确定研究区节理有6个较为明显的优势产状,构成3个节理系,并进一步确定了3期变形作用的构造应力场。海沟金矿早期受到NW--SE向伸展作用影响,使先存的近EW向海沟断层发生左行走向滑移,在海沟断层上盘形成NE向正断层组合,同时伴有含金石英脉的贯入;中期受到NEE--SWW向挤压作用,NE向正断层组合和发育于断层之中的含金石英脉受到压扭性变形作用的改造;晚期受到NW--SE向挤压作用,海沟断层表现为右行走滑的特征,NE向断层组合再次受到挤压作用改造,同时形成NWW向和NNW向走滑断层,使早期形成的断层和含金石英脉受到变形改造而发生空间上的错位。3期变形作用很可能是自白垩纪以来发生的,与太平洋板块向欧亚大陆的俯冲作用有关。更多还原

【Abstract】 Based on detailed study of the faults and joints in Haigou gold deposit,the joint occurrences are summarized and analyzed using stereographic projection method.Six preferred occurrences and three joint sets are recognized and their stress field during three stages of deformation is determined.The Haigou gold deposit underwent NW-SE extension at the early stage,which led to the left lateral strike slip of existing EW trending Haigou faults and formed NE trending normal fault at the hanging wall of Haigou fault,associated with the injection of gold-bearing quartz veins.During the middle stage,the deposit underwent NEE-SWW compression,led to the compressive reworking of NE trending normal faults and the gold-bearing quartz veins confined in the ore-controlling faults.At the late stage,the compression in NW-SE direction led to the right lateral strike slipping of Haigou fault,the NE trending faults reformed by compression again,and formed NWW and NNW trending strike slipping faults,which led to the deformation and displacement of the earlier faults and gold-bearing quartz veins.The three stages of deformation probably took place during Cretaceous,which related to the subduction process from the Pacific Plate to Eurasian Plate.更多还原