摘要
对出露于南秦岭陕西省凤县境内的花红树坪花岗闪长岩体进行LA-ICP-MS锆石U-Pb年代学和岩石地球化学研究,获得岩体表面年龄为214.3±2.7Ma(MSWD=2.6),表明其形成时代为晚三叠世。岩体的SiO_2=61.45%~65.10%,TiO_2=0.52%~0.63%;Al_2O_3=14.97%~15.74%,Mg O=2.33%~3.02%,Mg#=51.31~53.61,高Sr(485×10-6~563×10-6)和Sr/Y(28.2~30.4),低Y(17.0×10-6~19.1×10-6)和Yb(1.46×10-6~1.83×10-6),微弱负Eu异常(δEu=0.83~0.99),具有明显高镁埃达克岩地球化学特征。结合区域地质背景,认为花红树坪岩体是后碰撞构造环境下加厚下地壳拆沉熔融与先存地幔岩浆交代混染作用下的产物,其可能与凤太矿集区多金属矿成矿关系密切。
The Huahongshuping pluton, outcropped in south Qinling belt,Fengxian county, is composed principally of biotite granodiorite. LA-ICP-MS zircon U-Pb geochronological and petrogeochemical studies are determined. The results shows that the zircon 206Pb/238U weighted average ages of the rocks is 214.3±2.7Ma（MSWD=2.6）, indicating the crystallized-age of the pluton in late Triassic epoch. The SiO2= 61.45%-65.10%, TiO2=0.52%-0.63%, Al2O3=14.97%-15.74%, MgO=2.33%-3.02%, Mg#=51.31-53.61, high in Sr （485×10^-6-563×10^-6）, Sr/Y （28.2-30.4）, and low in Y （17.0×10^-6-19.1×10^-6）, Yb （1.46×10^-6-1.83×10^-6）, weakly negative Eu anomalies, suggests that the Huahongshuping pluton belongs to high-Mg adakitic rocks. Combined with the dataes of Qinling orogenic belt, the Huahongshuping pluton was formed in the tectonic setting of post-collisional orogeny, derived from partially melted of thicked lower crust delamination, mixed with mantle magma, and the polymetallic mineralization of Fengtai mineral cluster region likely has genetic relationship with it.
作者
张亚峰
杨涛
易鹏飞
姚征
何元方
ZHANG Ya-feng, YANG Tao, YI Peng-fei, YAO Zheng, HE Yuan-fang(Shaanxi Center of Geological Survey, Xi＇ an, Shaanxi 71006)
出处
《地质与勘探》
CAS
CSCD
北大核心
2018年第2期300-314,共15页
Geology and Exploration
基金
陕西省地质调查财政专项项目<陕西省凤太矿田西部基础地质调查(编号:20150101)资助
关键词
花岗闪长岩
年代学
岩石地球化学
花红树坪
南秦岭
granodirite, LA-ICP-MS zircon U -Pb dating, geochemistry, Huahongshuping, south Qinling
作者简介
张亚峰（1984年-），男，硕士，工程师，构造地质学专业，主要从事区域地质调查工作。E-mail：aimom84@163．com。
