新疆萨热克巴依盆内构造样式及对萨热克大型砂砾岩型铜矿床控制规律  

Tectonic patterns in the Sarekebayi apart-pull basin and their ore-controlling regularities for the Sareke glutenite-type copper deposit in Xinjiang,China

作　　者：方维萱[1,2] 王磊[1] 郭玉乾[1] 李天成[1] 贾润幸[1,2] 刘增仁[1] FANG Weixuan;WANG Lei;GUO Yuqian;LI Tiancheng;JIA Runxing;LIU Zengren(China Nonferrous Metals Geology Survey, Beijing 100012, China;Beijing Institute of Geology for Mineral Resources, Beijing 100012, China)

机构地区：[1]有色金属矿产地质调查中心,北京100012 [2]北京矿产地质研究院,北京100012

出　　处：《地学前缘》2018年第3期240-259,共20页Earth Science Frontiers

基　　金：国土资源部行业公益性科研专项"塔西砂砾岩型铜铅锌矿床成矿规律与找矿预测"(201511016-1);"新疆萨热克整装勘查区专项填图与技术应用示范项目"(12120114081501)

摘　　要：新疆乌恰县萨热克式大型砂砾岩型铜多金属矿床受萨热克巴依中生代陆内拉分断陷盆地控制显著,但该盆地内部构造古地理格架和构造样式不明。查明盆内构造样式特征,有助于提升对研究区内成矿规律认识和寻找隐伏矿体。采用构造岩相学填图新技术对该盆地内部构造样式及其对砂砾岩型铜多金属矿床控制规律进行研究,结果表明:(1)阿克苏岩群为盆地下基底构造层和半原地-异地地层系统。古生代地层为盆地上基底构造层和原地地层系统。早侏罗世成盆期为山前拉分断陷沉积形成的粗碎屑岩系,演进含煤碎屑岩系,最终为湖沼相黑色碳质泥岩-灰黑色粉砂岩-煤层。在中侏罗世主成盆期最大湖泛面以深湖相结晶灰岩、湖震相砾屑状泥灰岩-泥质砾岩和震积岩相泥灰质同生角砾岩等为标志,揭示三组NE向同生断裂带是成盆主控同生断裂带。早白垩世向上变粗的陆相碎屑岩系揭示该次级盆地萎缩封闭。(2)构造古地理格局为"三面环山,北西连通",在晚侏罗世初库孜贡苏期发生构造反转后,形成了周缘环山封闭式尾闾湖盆,为萨热克式砂砾岩型铜矿床形成提供了良好构造古地理格局。萨热克巴依次级盆地原型盆地为斜切西南天山造山带的山间盆地,构造动力学类型为中生代陆内拉分断陷盆地。(3)盆地内部构造样式(矿田沉积成岩成矿期构造系统)主要有裙边式复式向斜构造、NW向基底隆起构造带、古构造洼地、构造坡折带和同生断裂带、披覆褶皱等,这些构造样式和组合及后期构造变形样式对砂砾岩型铜多金属矿体控制明显。在隐伏基底隆起构造带上部受层间断裂裂隙带和岩相岩性带圈闭而聚集,推测矿质大规模聚沉机制为在该构造部位富烃类还原性成矿流体与岩相岩性多重耦合,富烃类还原性成矿流体与铜铁氧化物相岩石(含铜紫红色铁质杂砾岩类)强烈地球The Sareke copper deposit,a large-size glutenite-type copper deposit,had been controlled by the Sarekebayi Mesozoic secondary basin in Xinjiang,China.However,tectonic patterns in this basin remain unclear.To uncover the nature of the tectonic pattern in the basin,it is useful to promote a new high level research on the regularities of mineralization and search for the blind orebody in the studied area.Here,based on the new mapping methods of tectonic lithofacies,the following discoveries were made on the tectonic patterns in the basin and their ore-controlling regularities for the Sareke copper deposit：（1）The Meso-Proterozoic Akesu Group Complex constituted the lower base-tectonic layer attached to the semi-in situ allochthonous system of the strata;whereas the Paleozoic strata had been the upper base-tectonic layer attached to the in situ system of the strata.In the initial stage of the basin formation,the basin was first filled with coarse clastic rocks near the Lower Jurassic sedimentary-fault in the mountain-front,which later evolved into coal-bearing clastic rocks and eventually formed the carbonaceous mudstone,dark siltstone and coal layers in the limnetic facies.The maximum lake flooding plane at the Bathonian stage of the Middle Jurassic main basin formation,however,contained deep-lake,seiche and seismite facies of crystallized limestone,calcirudyte-marl and argillaceous conglomerate,and syngenetic argillo-calcareous breccia,respectively.It suggests that three groups of NE-trending syn-faults might be the main controlling factor for the basin-formation.The enclosure of this wilting intracontinental lake-basin was evidenced by the Lower Cretaceous clastic rocks with up-coarsening in the intracontinental facies.（2） The tectonic paleogeographical framework in the study area was surrounded by mountains on three sides and opened in the NW-trending.Tectonic inversion in the beginning of the Kuzigongsu Stage（the Callovian Stage）resulted in the mountain enclosed lake-basin.Consequently,the remnant o

关 键 词：砂砾岩型铜矿床 山间拉分盆地 盆内构造样式 裙边式向斜 隐蔽褶皱 

分 类 号：P618.41[天文地球—矿床学] P612[天文地球—地质学]