地质通报2016，Vol.35Issue(5)：750-765,16.
内蒙古中部红格尔图地区花岗岩的成因及构造背景--LA-ICP-MS锆石U-Pb年龄、地球化学的制约
Petrogenesis and tectonic setting of the granites in Honggeertu area, central Inner Mongolia：Constraints from LA-ICP-MS zircon U-Pb chronology and geochemistry
摘要
Abstract
Honggeertu granites, located in central Inner Mongolia and belonging to southern Solon-Linxi fault, is mainly composed of middle-fine to middle-coarse grained syenite granites and monzonitic granites. These granites have high SiO 2 (70.44%~78.80%) and are enriched in alkali (Na2O+K2O=7.46%~10.74%) but depleted in Mg, Fe and Ti. The A/CNK ratios are in the range of 0.95~1.41, alkali aluminum indexes (AKI) are 0.68~0.97, and alkalinities (AR) are 3.30~6.68, suggesting that the granites belong to weakly peraluminous-peraluminous alkaline series. The granite intrusion has widely varying total REE values (∑REE=25.96×10-6~654.50× 10-6), and is enriched in LREE and depleted in HREE with negative Eu anomaly (δEu=0.03~0.89). It is relatively enriched in high field strength elements (Th, U, Hf, Ta and Y) and depleted in large ion lithophile elements (Ba, Eu and Sr). The values of high field strength elements (Zr+Nb+Ce+Y) are higher than 350 × 10-6. The rocks belong to highly fractionated I-type granites formed in a post orogenic tectonic environment. Zircon LA-ICP-MS dating yielded 206Pb/238U weighted average ages, i.e., 267.2Ma ± 1.4Ma (MSWD=1.5), 269.2 ± 1.6Ma (MSWD=1.7) and 272.1 ± 1.2Ma (MSWD=0.38), indicating that the rock was formed in the Middle Permian. The new data suggest that the collision between NCC and Siberian Craton was earlier than the formation of the rock, and should be at least as early as 267.2~272.1Ma.关键词
红格尔图花岗岩/LA-ICP-MS锆石U-Pb测年/地球化学/后碰撞/构造/内蒙古Key words
Honggeertu granites/chronology/geochemistry/post-collision/structure/Inner Mongolia分类
天文与地球科学引用本文复制引用
蒋孝君,徐仲元,刘正宏,薛伟,剡鹏兵,邢亚杰..内蒙古中部红格尔图地区花岗岩的成因及构造背景--LA-ICP-MS锆石U-Pb年龄、地球化学的制约[J].地质通报,2016,35(5):750-765,16.基金项目
中国核工业地质局铀矿区域评价项目（编号201509）、中国地质调查局项目（编号:1212011120709）、中国国防科工局核能开发项目（2013-2016）和中国核工业地质局铀矿地质科研项目 （）
