黔西北五指山地区叠加构造变形特征对铅锌矿成矿的控制
Control on Leadzinc Mineralization Through Superimposing Structural Deformation in the Wuzhishan Area in NW Guizhou

摘要： 五指山铅锌矿区位于贵州省普定县与织金县交界区域，大地构造位于扬子板块中部、江南造山带西缘。野外构造研究表明，受早古生代加里东构造运动的控制与影响，矿区内震旦系—下古生界构造变形与上古生界—中生界的构造变形明显不同。震旦系—下古生界构造线近东西向，发育近东西向平缓褶皱、南倾或北倾劈理，显示近南北向的挤压收缩变形。震旦系—下古生界区内发育两组南北、北西向陡倾断层，断层明显受限制而不穿越晚古生代之后的地层。发育在震旦系—下古生界内的层间滑动与断层活动控制着铅锌矿的分布。晚古生代之后区域构造应力场发生转变，由早期近南北向的挤压收缩转为早燕山期SEE向NWW挤压逆冲，由此对震旦纪—早古生代变形进行叠加与改造，宏观上形成以NE走向为特征的区域构造格局。后期形成的褶皱轴面主要向SEE倾斜，断层向NWW逆冲，与早期变形呈斜跨式叠加。燕山期断层活动促进了铅锌矿的迁移与聚集。
Abstract: The Wuzhishan leadzinc ore district is located at the junction of Puding and Zhijin in Guizhou Province. The district is tectonically situated at the center of the Yangtze craton, close to the western margin of the Jiangnan orogen. Based on the field structural research, this study found that clear differences between the SinianEarly Paleozoic and Late PaleozoicMesozoic structural deformation features, which were controlled or influenced by the Early Paleozoic Caledonian tectonic movement. The structural line of SinianEarly Paleozoic is EWtrending, gently EW folded with south or northdipping cleavages, which shows the NStrending compressive deformation. Two sets of NSand NWtrending highpitched faults were developed in the SinianEarly Paleozoic, which were obviously restricted that did not crosscut the postLate Paleozoic sequences. SinianEarly Paleozoic interlayer gliding and faulting activities control the distribution of leadzinc orebodies. Regional tectonic stress field was likely changed after the Late Paleozoic, from early NStrending compression to early Yanshanian WNWtrending(ESEdipping) thrusting, which superposed and deformed the SinianEarly Paleozoic structures, and formed the regional NEtrending tectonic pattern. The latestage fold axis dips mainly to ESE and the faults thrust to WNW, obliquely superposed on the early deformation. The Yanshanian faulting may have promoted the migration and enrichment of the leadzinc ores