广西铜坑锡多金属矿构造特征及控矿作用  

Characteristics of Structures and Controls on Mineralization of Tongkeng Tin-Polymetallic Deposit in Guangxi

作　　者：徐明[1,2] 蔡明海[2] 彭振安[2] 张诗启[2] 陈艳[2] 王显彬[2] 

机构地区：[1]北京西蒙矿产勘查有限责任公司,北京100012 [2]广西大学资源与冶金学院,广西南宁530004

出　　处：《大地构造与成矿学》2011年第4期587-595,共9页Geotectonica et Metallogenia

基　　金：广西大厂锡石硫化物型锡矿科学基地研究项目(编号200911007-13);桂东-粤西地区典型矿床矿田构造研究项目(编号20089946-3);丹池锡铜铅锌银锑汞成矿带找矿预测研究项目(编号GYDK090006)资助

摘　　要：铜坑锡多金属矿位于丹池成矿带中部大厂矿田内。构造研究表明,区内构造主要经历了海西期拉张拗陷、印支期挤压变形和燕山晚期拉张作用。大厂背斜轴迹由北北西转为北西西部位与大厂背斜枢纽隆起部位两者的叠加是形成铜坑矿的有利构造。矿床上部由于岩层压力较小,处于相对开放体系,构造变形多以NE向张或张扭性断裂、裂隙为主,矿床下部由于上覆岩层压力较大,岩性间物理性质差异较大,在拉张作用下产生一系列层间滑动破碎带,此种构造样式的垂向分带决定了铜坑矿区上脉下层的矿体形态。此外,构造地球化学研究显示,Sn、Pb、Sb等成矿元素在印支期挤压变形层中无富集趋势,而在燕山晚期的伸展剪切变形层、SN向张扭性断裂、以及受燕山晚期张扭性改造的NW向F1断裂中明显富集,Zn、Cu元素的富集与Sn、Pb、Sb元素始终不同步,其受断裂和拉张作用的影响较小。在此基础上,提出了铜坑锡多金属矿的构造控矿模型,并总结了矿床、矿体定位的构造组合形式。The Tongkeng tin-polymetallic deposit is located in the middle of the Dachang metallogenic belt.Detailed structural studies show that this region underwent three stages of structural deformations,sequently,Hercynian tensional depression,Indo-Sinian compressional deformation and stretch slide in late Yanshanian.The Tongkeng ore field is located on the favourable place where two parts superposed,namely,axis of the Dachang anticline swerving section from NNW-to NWW-trending,and upheaval of the Dachang anticline.The structure at the hanging wall of the orebody is a relatively open system due to low pressure,showing structural deformation of NE-trending—mainly tensional or trans-shear faults and crannies.The structure at the foot wall of the orebody is interlayer sliding faulted zone because of high pressure and physical property difference in lithology.The structural characteristics constraint the veinlet ore structure at the hanging wall and layered structure in the foot wall in the Tongkeng ore filed.Tectonic geochemical profiles show that Sn,Pb and Sb were not enriched in the compression deformation layer of the Indo-Sinian,but obviously enriched in the SN-trending faults,NW-trending F1 fault and the extension shear layer in the late Yanshanian.Influenced by fault and stretch weakly,the enrichment of Zn and Cu was discrepancy with Sn,Pb and Sb spatially.Thus,the mine-controlled model in the Dachang ore filed was put forward and structure assemble pattern which controls the position of ore filed,deposits and orebodies were summarized.

关 键 词：构造特征 控矿模型 锡矿田 铜坑 广西 

分 类 号：P613[天文地球—矿床学]