中昆仑北部地区构造地层学初步研究

Preliminary Research on the Tectonostratigraphy in the Northern Central Kunlun Orogenic Belt

中昆仑北部造山带可分为 5个构造地层区 :白干湖、求勉雷克、大九坝、祁漫塔格南缘和祁漫塔格北缘。白干湖和求勉雷克构造地层区出露前寒武纪变质结晶基底 ;早古生代期间 ,祁漫塔格洋沿鸭子泉—阿特阿特坎河断裂向北西俯冲碰撞 ,在祁漫塔格北缘沉积了古海沟岛弧浊积岩、晚泥盆世蛇绿混杂岩 ,在祁漫塔格南缘被动大陆边缘上发育晚泥盆世前陆磨拉石沉积 ;晚古生代早期 ,昆中求勉雷克地区简单剪切滑覆 ,在祁漫塔格南、北缘形成浅海相沉积 ,而大九坝地区由于断层高角度伸展 ,沉积了一套海相碳酸盐岩建造 ;晚古生代晚期 ,特提斯洋沿昆中断裂斜向俯冲 ,在大九坝出露了托库孜达坂蛇绿混杂岩和早二叠世前陆盆地堆积 ;晚三叠世陆相火山岩出露于祁漫塔格山南缘。

The northern central Kunlun orogenic belt can be divided into five tectonostratigraphical regions, namely, the Baiganhu, Dajiuba, Qiumianleike regions, the northern and southern margins of the Qimantage mountain region. In the Baiganhu and the Qiumianleike regions the Proterozoic metamorphical crystalline basements are exposed. Along the northern margin of the Qimantage mountain the Early Palaeozoic ophiolite complex, the trench arc system turbidite, the Upper Devonian foreland molasse basin sediment and Late Palaeozoic stable platform covers crop out. In the southern margin of the Qimantage mountain, the Early Palaeozoic slope and shelf were deposited on which passive continental margin at that time, and Upper Devonian foreland molasse basin sediment, Lower Permian backland molasse basin sediment and Late Triassic volcanic rock are exposed. In the Dajiuba region, the Late Palaeozoic stable covers, ophiolite complex and the Early Permian foreland molasse basin sediment are exposed.