湘黔边境加里东板内造山期后正向滑脱构造与成矿

POSITIVE DECOLLEMENT AND MINERALIZATION OF INTRAPLATE CALEDONIAN POSTORGENIC PHASE ON THE BORDER OF HUNAN AND GUIZHOU PROVINCES

湘黔边境地处扬子板块东南缘,加里东运动是区内古生代最强烈的板内造山运动;由新元古界板溪群至下古生界奥陶系所构成的NE—NNE向褶皱带为区内主体构造;近期区域地质调查所发现的加里东造山期后,构造体制由挤压转换为伸展所产生的一套正向顺层滑脱构造系统更具特色,不但空间结构完整,构造变形清楚,正向顺层滑脱标志明显,而且成矿控矿作用突出,是湘黔边境著名汞矿带的重要控矿构造。

The research area is located on the border between Hunan and Guizhou Provinces.It lies on the southeast margin of the Yangtze Plate,where the Caledonian was the most prowerful intraplate orogeny during the Paleozoic era.The major structure in the area is the NE-NNE folded belt consisting of Banxi Group of the Middle Proterozoic era to the Ordovician system of the Early Paleozoic era.Recent regional geological investigations show that a series of positive decollement system formed by the structural mechanism transforming from compression to extension is more characteristic by its perfect spacial structure,clear structural deformation,obvious indication of the positive decollement.Also this series and remarkable mineralization.Hence,this positive decollement should be the important structure controlling the mercury ore belt on the border area.