摘要
石棉矿花岗岩体位于乌兰乌珠尔地区西北部,岩性主要是中细粒黑云母二长花岗岩。笔者采取了5件花岗岩岩石样品进行地球化学分析,结果显示石棉矿花岗岩具有高硅、富碱、富铝、贫镁钙的特点,属于高钾钙碱性系列;A/CNK值为1.06~1.62。微量元素以富集Rb、Th、U,亏损Ba、P、Eu、Ti、Sr为特征;稀土元素含量为66.31×10^(-6)~141.13×10^(-6),富集轻稀土,LREE/HREE为4.03~13.00。具有明显的Eu负异常,δEu值为0.21~0.46。U含量为1.65×10^(-6)~4.42×10^(-6),Th/U比为3.4~7.9。初步研究表明,石棉矿花岗岩为形成于岩石圈伸展的地球动力学背景下的过铝质分异S型花岗岩。
Shimiankuang granitic pluton is located in the northwest of Wulanwuzhuer area,which are mainly medium to fine grained biotitic-monzonitic granite.Five samples were collected for geochemistry analysis.These granites are characterized by being rich in silica,alkali,aluminium,and negative in magnesium and calcium.The value of A/CNK spreads within the limits of 1.06~1.62.All samples from Shimiankuang granitic pluton in this study are high-K calc-alkaline rocks.They are rich in Rb,Th,U,and depleted in Ba,P,Eu,Ti and Sr in the primitive mantle-normalized spidergrams.The contents of rare earth elements are 66.31 ×10^(-1)~141.31 × 10^(-6),and rich in LREE,the value of LREE/HREE ranges from 4.03 to 13.00.They all show prominent negative Eu anomalies with 8Eu value of 0.21~0.46.The content of U is 1.65 ×10^(-6)~4.42 × 10^(-6),and the value of Th/U ranges from 3.4~7.9.These features are coincident with peraluminous differentiation S-type granite,which is viewed as under a regional lithospheric extension tectonic setting.
出处
《世界核地质科学》
CAS
2015年第3期139-144,共6页
World Nuclear Geoscience
基金
优先发展技术项目:航空高空间分辨率遥感技术推广应用研究(项目编号:遥YX162-2)
关键词
石棉矿花岗岩体
地球化学特征
岩石成因
Shimiankuang granitic pluton
geochemical characteristics
petrogenesis
