安徽广德地区庙西岩体锆石U-Pb年代学及岩石地球化学特征  

ZIRCON U-PB GEOCHRONOLOGY AND PETROGEOCHEMISTRY OF THE MIAOXI PLUTONS IN THE GUANGDE AREA,ANHUI PROVINCE

作　　者：何苗[1] 王翔[1] 邓佳良 吴家富[1] 吴昊 吴衡[1] HE Miao;WANG Xiang;DENG Jia-liang;WU Jia-fu;WU Hao;WU Heng(Institute of Geological Survey of Anhui Province(Institute of Geological Sciences of Anhui Province),Hefei,Anhui 230001,China)

机构地区：[1]安徽省地质调查院(安徽省地质科学研究所),安徽合肥230001

出　　处：《安徽地质》2021年第3期193-200,224,共9页Geology of Anhui

基　　金：安徽省公益性地质调查基金项目“安徽省山北、流洞桥、社渚、泗安幅(省内部分)1∶5万区域矿产地质调查”(2016-g-2-11)资助。

摘　　要：本文通过岩相学、岩石地球化学、锆石U-Pb定年等方法,对出露于安徽省广德地区的庙西岩体进行了研究。结果表明:庙西岩体主要由二长花岗岩、正长花岗岩组成,两类花岗岩的成岩时代分别为(128.2±1.5)Ma,(124.9±1.5)Ma,代表了皖南地区早白垩世晚期两阶段岩浆活动。庙西岩体属于高钾钙碱性岩石,两类花岗岩均具有高硅、富碱、高FeOT/MgO和10000*Ga/Al值,低Al_(2)O_(3)、MgO、CaO特征;具有明显的Eu负异常,显示A型花岗岩特征。形成于造山后的板内伸展环境,花岗质岩浆应起源于地壳物质的部分熔融。This paper deals with the Miaoxi plutons outcropped in the Guangde area,Anhui Province using petrography,petro-geochemistry and zircon U-Pb dating.The results show that the Miaoxi plutons are mainly composed of monzonite and syenite,whose diagenetic ages are(128.2±1.5)Ma and(124.9±1.5)Ma,respectively,which represent two stages of magmatic activity in the late Early Cretaceous in southern Anhui.The Miaoxi granites belong to high-K calc-alkaline rocks.The two types of granites are characterized by high silicon,rich alkali,high FeOT/MgO and 10000*Ga/Al values,and low Al_(2)O_(3),MgO and CaO,indicating obvious negative Eu anomaly,and characteristics of a-type granite.It is suggested that they were formed in an intraplate extensional environment after orogeny,and the granitic magma originated from partial melting of crustal material.

关 键 词：庙西岩体 锆石U-PB年代学 地球化学特征 构造背景 皖南地区 

分 类 号：P597[天文地球—地球化学]