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
