诸广岩体南部黄溪断裂多期次活动特征与铀成矿

Multi-stage Activity Characteristics and Uranium Mineralization of Huangxi Fault in the Southern Zhuguang Rock Mass

以诸广岩体南部地区NE向黄溪断裂为主要研究对象,分析其构造活动特征,探讨其与铀成矿的关系。通过对黄溪断裂地貌、断裂面形态、复式构造岩、构造蚀变、低次序构造、脉体活动及物质迁移等方面的分析,认为该断裂具多期次活动的特点;该断裂中的铀矿化主要形成于以张(张扭)性为主、张→压→张等多次往复应力转换时期;该断裂垂向上陡缓过渡区域的次级断裂及羽裂隙具有一定的成矿潜力。参考中生代以来区域地质演化成果,根据黄溪断裂多期次活动与铀成矿的关系,编制了黄溪断裂多期次活动示意图,认为该断裂经历了燕山早期挤压形成,燕山晚期多期次构造应力挤压、拉张反复作用,喜山期以拉张为主的构造活动。

Taking the NE-trending Huangxi fault in the southern part of Zhuguang rock mass as the main research object,the characteristics of its tectonic activity are analyzed,and its relationship with uranium mineralization is discussed.Through the analysis of the landform,fracture surface morphology,complex tectonite,tectonic alteration,low-order structure,vein activity and material migration of Huangling fault,it is considered that the fault has the characteristics of multi-stage activity.The uranium mineralization in the fault is mainly formed in the period of multiple reciprocating stress conversion such as tension(tension-torsion)and tension→compression→tension.The secondary faults and feather fractures in the vertical steep and gentle transition area of the fault have certain metallogenic potential.Referring to the results of regional geological evolution since Mesozoic,according to the relationship between multi-stage activities and uranium mineralization,the schematic diagram of multi-stage activities of Huangxi fault is compiled.It is believed that the fault was formed by compression in the early Yanshan period,repeated action of multi-stage tectonic stress compression and tension in the late Yanshan period,and tectonic activity dominated by tension in the Himalayan period.