摘要
大田地区中生代岩浆岩普遍具有高硅、高铝的特点。汤泉岩体花岗闪长岩中锆石LA-ICP-MS U-Pb年龄为168±3 Ma,其样品中La/Yb较高,Eu亏损不明显,具有高Sr、低Y的地球化学特征,符合埃达克质岩特征,其形成与地壳增厚有关,处于挤压构造背景下;NNE向脉岩群样品锆石LA-ICP-MS U-Pb加权平均年龄为138±3 Ma,部分脉岩群样品可划分为强过铝质,脉岩群样品中La/Yb较小,Eu绝对值较小,亏损严重,为挤压阶段末期形成;太华岩体La/Yb较高,Eu轻度亏损,Rb-Sr等时线年龄为114.89±2.2 Ma,是西太平洋板块俯冲、地壳减薄的伸展构造背景下形成。
Mesozoic magmatic rocks in Datian area,Fujian province,are usually rich in SiO2 and Al2O3 content.Tangquan granodiorite which yielded zircon LA-ICP-MS U-Pb age of 168±3 Ma has high La/Yb and Sr,slightly Eu depletion,and poor in Y,is similar to adakite in geochemistry,indicate that it＇s formed in compressional setting related to crust thickening.NNE-trending granite veins which yielded zircon LA-ICP-MS U-Pb age of 138＋3 Ma has low La/Yb value and intensive Eu depletion,indicate that it＇s formed in late stage of compression process.Taihua granite which yielded Rb-Sr isochron age of 114.89±2.2 Ma has high La/Yb value and slightly Eu depletion,may be formed in extensional setting related to crust thinning when West Pacific subduction.
出处
《华南地质与矿产》
CAS
2011年第3期201-207,共7页
Geology and Mineral Resources of South China
基金
建省大田县铅锌铜金属矿产成矿规律研究"项目资助
关键词
岩浆岩
地球化学
锆石年代学
构造环境
中生代
大田地区
闽西南
magmatic rock
geochemistry
zircon chronology
tectonic environment
Mesozoic
Datian
Southwest Fujian
作者简介
作者简介：范旭光（1980-），男，助理工程师，现主要从事地质勘查工作．E-mail：fanlion@yahoo．cn
