中文摘要：

通过对大青山哈拉合少岩体基本地质特征研究,包括岩石矿物学特征、岩石化学和地球化学特征、同位素年代分析等,对岩体形成时代和形成构造环境有了一些认识：锆石U-Pb等时线测年分析结果表明,206Pb/238U表面年龄计权重平均值为261.1 Ma±0.5 Ma,代表哈拉合少岩体侵位时代;岩石化学分析结果和岩石学特征表明,该岩体为I型与S型混合成因花岗岩,主要由壳源物质重熔形成。根据地球化学分析结果,结合形成的构造背景,认为该岩体是在西伯利亚板块向南俯冲与华北板块北缘碰撞晚期的应力松驰阶段形成的,属造山期同碰撞花岗岩。

英文摘要：

This paper probes into the age and formation environment of Halaheshao pluton according to the research of macroscopic geological characteristics, the analysis of petrological minerals,petrochemistry and isotopic geochronology. The result of U-Pb dating analysis of zircon indicates that the weighted average apparent age of 206Pb/238U is 261.1 Ma±0. 5 Ma,which represents the time of Halaheshao pluton formation. It is considered that pluton belong to the mixing origin granite of I-type and S-type, which mainly formed by anatexis of crust materials based on the result of petrochemistrical analysis and petrological characteristics. Halaheshao pluton is syncollision granite, formed in the stage of stress relaxation during the late period of collision of Siberia plate diving southwards to the northern margin of North China plate.