粤北长江铀矿田控矿构造解析  

Analysis of Ore-Controlling Structure of Changjiang Uranium Ore Field,Northern Guangdong

作　　者：陈柏林[1] 高允 申景辉 曾广乾 Chen Bailin;Gao Yun;Shen Jinghui;Zeng Guangqian(Ministry of Natural Resources Key Laboratory of Paleo Magnetism and Tectonic Reconstruction,Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China)

机构地区：[1]中国地质科学院地质力学研究所自然资源部古地磁与古构造重建重点实验室,北京100081

出　　处：《地球科学》2022年第1期159-177,共19页Earth Science

基　　金：国家重点研发项目(Nos.2017YFC0602602,2016YFC0600207);院所长基金项目(No.JYYWF20180602)。

摘　　要：控矿构造研究是长江铀矿田的薄弱环节,制约了成矿规律的深入探讨和进一步找矿方向.通过对矿田内控矿构造的详细解析,厘定了控矿构造形式,构建了构造控矿模型,探讨了控矿构造的演化,指出了找矿方向.铀矿田内的矿体和矿化带受北北西(近南北)向展布的小型断裂构造控制,具有走向延伸长、倾向延深大、产状比较稳定、局部弧形形态、呈带状成群出现等特点,显示含矿构造是形成于近东西向挤压条件的压性、压扭性断裂构造(密集节理带或劈理带).铀矿田的控矿构造是北北西(近南北)向的较大规模断裂构造(主断裂)系统,这个主断裂与深部成矿流体连通,起到导矿-配(运)矿作用,浅部连接作为含矿构造的北北西(近南北)向的次级断裂和密集劈理带,后者构成了铀矿体的赋存空间,控制了铀矿体产出.控矿构造经历了含矿构造形成期、基性岩脉侵位期、成矿期、成矿后小位移断错和隆升剥露共5个阶段的演化,最终形成目前的状态.油洞断裂不是控矿构造,仅局部含矿,棉花坑断裂为成矿后断裂.依据对控矿构造系统的认识,矿田内进一步的找矿方向是近南北(北北西)向铀矿化蚀变带沿走向延伸部位和倾向深部,同时现有地表或浅部矿带之间的空白区存在隐伏矿带的可能性也非常大.The study of ore-controlling structures is still weak in the Changjiang uranium ore field,which has restricted the understanding of metallogenic regularity and future prospecting direction.Through detailed analysis of ore-controlling structure in ore field,the authors determined the ore-controlling structure form,constructed a structural ore-controlling model,discussed the evolution of ore-controlling structure,and pointed out the prospecting direction in this study.It is found that uranium ore bodies and mineralization belts in the ore field are controlled by NNW-trending(near SN-trending)fault structure and are characterized by a long strike extension,a large dip depth,a stable occurrence with some arcuate shape and belted groups,which indicates that the ore-bearing structures are compressive or/and compresso-shear fault(closely spaced joint or/and cleavage belt)forming under an EW-trending compressive stress field.However,the ore controlling structure in the ore field is a larger scale NNW-trending(near SN-trending)fault structure system(or main fault),in which deep part links the ore-forming solution in depth and acts as passageway for the ore fluid and shallow part links the ore-bearing NNW-trending(near SN-trending)fault structures.They not only act as the host space but also control the occurrence of ore-bodies.The ore-controlling structure went through five stages as forming stage of ore-bearing structure,emplacement stage of basic dike,metallogenic stage,forming stage of brittle fracture after mineralization and uplifted-exhumation stage,finally appearing the present state.The Youdong fault is not a high degree orecontrolling structure,it only acts as ore-bearing structure.The Mianhuakeng fault maybe occurred after mineralization.On the basis of the ore-controlling structure,the further prospecting for uranium deposits should be along the NNW-trending(near SNtrending)fault belt,concentrated in the strike extending area and deep dipping area.In the meantime,there is a good chance for concealed ore zone in

关 键 词：控矿构造 含矿构造 找矿方向 长江铀矿田 粤北 矿床学 

分 类 号：P613[天文地球—矿床学]