地质通报2015，Vol.34Issue(12)：2246-2253,8.
西藏狮泉河地区仁温斜长花岗岩LA-ICP-MS锆石U-Pb年龄及其构造意义
LA-ICP-MS zircon U-Pb age of Ren-wen plagiogranite pluton in Shiquan River area, Tibet
摘要
Abstract
s:The Renwen plagiogranite in Shiquan River area of Tibet consists of oligoclase, quartz, etc. The zircon U-Pb weighted average age measured by LA-ICP-MS is 162.5 ± 2.6Ma. The major elements are characterized by SiO2 content from 72.05% to 72.83%, Al2O3 content from 12.72%to 13.54%, MgO content from 1.19%to 1.24%, Mg# values from 35.73 to 42.27, Na2O content from 4.56%to 4.74%, low K2O content from 0.34%to 0.57%, and Na2O/K2O values from 8.32 to 13.41. The major element geo-chemistry of Renwen plagiogranite belongs to low potassium calc-alkaline series. Geochemical characteristics of plagiogranite and me-tabasite suggest that the Renwen plagiogranite may have been derived from partial melting of metabasite, which shows island-arc vol-canic characteristics, being enriched in LILE such as Rb, Sr, Ba and depleted in HFSE such as Nb, Ta, Ti. It is concluded that subduc-tion took place in Middle Jurassic in the Shiquanhe suture (the north branch).关键词
狮泉河地区/斜长花岗岩/LA-ICP-MS锆石U-Pb年龄/中侏罗世Key words
Shiquan River/plagiogranite/LA-ICP-MS zircon U-Pb age/Middle Jurassic分类
天文与地球科学引用本文复制引用
尼玛次仁,王国灿,顿都,叶强,普尺,焦文龙,次仁央宗,洛桑朗杰,李开云..西藏狮泉河地区仁温斜长花岗岩LA-ICP-MS锆石U-Pb年龄及其构造意义[J].地质通报,2015,34(12):2246-2253,8.基金项目
中国地质调查局项目(编号:1212011121232、1212011221057) （编号:1212011121232、1212011221057）
