【摘要】 位于东昆仑中段五龙沟地区深水潭矿段糜棱岩化钾长花岗岩LA-ICP-MS锆石U-Pb年龄为（390±3.9）Ma。该岩体具有较高的SiO₂（74.86%⁷6.64%）、K₂O（5.20%⁶.06%）和全碱含量（K₂O+Na₂O=8.05%⁸.83%）,呈现明显的Ba、Nb-Ta、Sr、P和Ti的负异常,以及强烈的Eu负异常（δEu=0.07⁰.12）,显示A型花岗岩特征。结合区域上志留纪—泥盆纪岩浆岩的研究,认为东昆仑造山带早泥盆世已进入后碰撞伸展阶段,早中泥盆世之交为伸展最强烈时期,形成了颇具规模的在A型花岗岩,也代表加里东造山旋回的结束。更多还原

【Abstract】 The mylonited granite is located at Shenshuitan mining setion of Wulonggou area in the middle part of the East Kunlun,with a yielded LA-ICP-MS zircon U-Pb age of 389.7±3.9 Ma.This granite has high SiO₂（74.86%⁷6.64%）,K₂O（5.20%⁶.06%）and total alkali content（K₂O + Na₂O= 8.05%⁸.83%）values.The samples are characterized by strong loss in Ba,Nb-Ta,Sr,P and Ti,as well as strong negative Eu anomaly（δEu = 0.07⁰.12）,which shows characteristics of A type granite.Combined with the studies of Silurian-Devonian magmatic rocks in this studying area,it’s proposed that the East Kunlun Orogenic belt has entered the post-collision stage in early Devonian,and the most intense of extension was happened in the conversion period of from early Devonian to middle Devonian,forming A type granite with considerable size,and standing for the end of the Caledonian orogenic cycle.更多还原