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.
作者
何苗
王翔
邓佳良
吴家富
吴昊
吴衡
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)
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。
