地质通报2012，Vol.31Issue(10)：1565-1575,11.
内蒙古阿拉善右旗杭嘎勒晚二叠世二长花岗岩地球化学特征和LA-ICP-MS锆石U-Pb定年
Geochemical characteristics and LA-ICP-MS zircon U-Pb dating of the Late Permian monzogranite in Hanggale, Alax Right Banner, Inner Mongolia
摘要
Abstract
Late Permian monzogranite of Hanggale is characterized by rich alkali metals, poor MgO, TFeO and CaO, enrichment of LREE, and weak negative Eu anomalies, implying an I-type granite. The depletion of Nb, Sr, P, Ti elements shows that such an arc granite has features of intrusive rocks related to subduction. In the R1 -R2 diagram, most of the samples are concentrated along the boundary between the pre-collision granite area and the post-collision granite area. In the Nb-Y diagram, the samples fall into the area of the volcanic arc-syncollisional granite. In the Rb -(Y+Nb)diagram, the samples lie in the area of volcanic arc granite. In the Rb-Hf-Ta diagram, the samples all fall into the arc system. High Th/U ratios in zircon of main rocks show characteristics of magmat-ic zircons; high total REE, heavy REE enrichment and left-oblique curves in the chondnte-normalized diagram are consistent with general characteristics of magmatic zircon distribution. LA-ICP-MS zircon U-Pb dating shows that its age is 253.5±7.9Ma. The Late Permian monzogranite of Hanggale was a pre-collisional volcanic arc granite, and Hanggale area was a volcanic arc that belonged to active continental margin in Late Permian.关键词
地球化学特征/LA-ICP-MS锆石U-Pb定年/二长花岗岩/晚二叠世/杭嘎勒Key words
geochemical characteristics/LA-ICP-MS zircon LJ-Pb dating/ monzogranite/ Late Permian/Hanggale分类
天文与地球科学引用本文复制引用
冉皞,张维杰,刘治博..内蒙古阿拉善右旗杭嘎勒晚二叠世二长花岗岩地球化学特征和LA-ICP-MS锆石U-Pb定年[J].地质通报,2012,31(10):1565-1575,11.基金项目
中国地质调查局国土资源大调查项目《内蒙古1∶5万杭嘎勒幅、哈尔扎盖幅区域调查》(编号:K48E02005 1212010610419) （编号:K48E02005 1212010610419）
