喀喇昆仑地区早二叠世弧后盆地

EARLY PERMIAN BACK ARC BASIN IN THE KARAKORUM MOUNTAINS

喀喇昆仑山北坡明铁盖地区早二叠世的基性火山岩岩石化学和地球化学特征表明，它是一种既具有在硅铝质基底上扩张的洋脊玄武岩性质，又具有钙碱性岛弧拉斑玄武岩特点的弧后盆地火山岩。这一弧后盆地的形成与沿西金乌兰湖—空喀山口至乔戈里峰一线的古特提斯洋盆的扩张及向北俯冲、消减相联系，构成了塔里木板块南部晚古生代活动大陆边缘。

The petrochemical and geochemical features of Early Permian basic volcanic rocks in the Mingteke area on the north slope of the Karakorum Mountains indicate that the rocks are back arc basin volcanic rocks with both the nature of spreading ocean ridge basalt on the sialic basement and the characters of calc alkaline island arc tholeiite.The formation of this back arc basin was related to the spreading and northward subduction of the Paleo Tethys oceanic basin along the line from the Xijir Ulan Lake Kongke Mountain Pass to Mount Qogir,which gave rise to the Late Paleozoic active continental margin of the southern Tarim plate.