地质论评2013，Vol.59Issue(2)：369-381,13.
闽西南虎岗地区晚中生代花岗岩LA-MC-ICP-MS锆石U-Pb年龄、地球化学特征及地质意义
LA-MC-ICP-MS Zircon U-Pb Dating, Geochemical Features of the Two Granites in Hugang Area, Southwestern Fujian and Their Geological Significances
摘要
Abstract
The LA-MC-ICP-MS U -Pb dating of the zircons from the two granites in Hugang area, the southwestern Fujian, are carried out. The results show that the n(206Pb)/n(238U) ages of the zircons from the Zengkeng fine grain monzonitic granite change from 145.4 ±18.2 Ma to 151.4 ±7.9 Ma,and the weighted average U-Pb age is 147. 98 ±0. 86Ma ( 95% conf. ,MSWD = 0. 62). The n(206Pb)/n(238U) ages of the zircons from Guanyang medium-fine biotite monzonitic granite change from 141. 2 ± 4. IMa to 145. 5 ± 1. 9Ma, and the weighted average U-Pb age is 143. 0 ± 1. 1 Ma (95% conf. , MSWD = 0. 41 ). Moreover, the content of trace elements indicate that two plutons were formed in the collision-extrusion tectonic environment and were of strong magmatic differentiation and high magma acidity, n ( Al2 O3) > [ n ( CaO) + n ( Na2 O) + n (k2 O ],the rates of Rb/ Sr and Rb/Nb are higher, but the contents of Ni, Cr are lower and REE patterns are the rightly-oblique, which also suggest that the two plutons derive from continental crust and belong to aluminum supersaturation S-type granites. The Zengkeng and Guangyang granites are formed in the Late Jurassic ( mid-late Stage of Yanshanian) and provided main material foundation for formation of iron, manganese and copper deposit.关键词
花岗岩/锆石U-Pb定年/地球化学/虎岗地区/福建Key words
granite/LA-MC-ICP-MS zircon U-Pb dating/ geochemical feature/Hugang area/ Fujian province引用本文复制引用
沈莽庭,周延,张晓东,武彬..闽西南虎岗地区晚中生代花岗岩LA-MC-ICP-MS锆石U-Pb年龄、地球化学特征及地质意义[J].地质论评,2013,59(2):369-381,13.基金项目
本文为国土资源大调查项目(编号1212011085465)的成果. （编号1212011085465）
