地质通报2012，Vol.31Issue(6)：860-874,15.
青藏高原祁漫塔格地区早古生代火山岩岩石构造组合和LA-ICP-MS锆石U-Pb年龄
Petrotectonic assemblages and LA-ICP-MS zircon U-Pb age of Early Paleozoic volcanic rocks in Qimantag area, Tibetan Plateau
摘要
Abstract
A study of the Early Paleozoic volcanic rocks in Qimantag area reveals that they were formed in the Middle-Late Ordovi-cian period. The volcanic rocks can be assigned to four volcanic rock belts, i.e., Gonglugou - luanshigou belt, Kuangou - Xi-aolangyashan belt, Bayan Gol-Suhait belt and Naling Gol belt. The first volcanic rock belt belongs to a combination of Nb-enriched basalts characterized by high content of Nb (7.38×10-6-10.1×10-6), TiO2 (1.56%-2.24%) and P2O5 (0.24%-0.34%). The combinations of the volcanic rocks in the second belt are complicated, the SiO2 mass fractions of these rocks are concentrated on two end members, and these rocks can be further divided into two sub-combinations of basalt+basatic andesite and dacite+lithoidite. U-Pb LA-ICP-MS analyses of zircons in basalt and lithoidite yielded the data of 440.2±2.4Ma and 450.3±1.2Ma, respectively. The content of TiO2 (1.1%) and K2O(0.14%) is low while that of Na2O(2.17%) is high for the rocks of the tholeiite combinations in the third belt. Although the content of TiO2 (1.64%) is relatively high, the tholeiite combinations in the fourth belt are very similar to those in the third belt.关键词
祁漫塔格地区/早古生代/海相火山岩/LA-ICP-MS锆石U-Pb年龄Key words
Qimantag area/ Early Palaeozoic/ marine volcanic rocks/ LA-ICP-MS zircon U-Pb age分类
天文与地球科学引用本文复制引用
王秉璋,罗照华,潘彤,宋泰忠,校培喜,张志青..青藏高原祁漫塔格地区早古生代火山岩岩石构造组合和LA-ICP-MS锆石U-Pb年龄[J].地质通报,2012,31(6):860-874,15.基金项目
青海省科学技术厅应用基础研究项目《青海省东昆仑祁漫塔格火成岩类成矿作用及找矿靶区优选》(编号:2010-Z-705)和中国地质调查局柴达木周缘及邻区成矿带地质矿产调查评价专项《青海1∶5万滩北雪峰地区四幅区域地质调查》(编号:1212010781056)、《青海1∶5万喀雅克登塔格地区五幅区域地质调查》(编号:1212010710321)、《青海1∶5万乌兰乌珠尔—祁漫塔格地区八幅区域地质矿产调查》(编号:1212010610312) （编号:2010-Z-705）
