川西可尔因伟晶岩型稀有金属矿床的^(40)Ar／^(39)Ar年代及其构造意义  

^(40)Ar/^(39)Ar Ages of the Keeryin Pegmatite Type Rare Metal Deposit, Western Sichuan, and Its Tectonic Significances

作　　者：李建康[1,2] 王登红[2] 付小方 

机构地区：[1]中国地质大学,北京100083 [2]中国地质科学院矿产资源研究所 [3]四川省地质科学研究所,北京100037

出　　处：《地质学报》2006年第6期843-848,共6页Acta Geologica Sinica

基　　金：国家自然科学基金青年基金项目(编号40202012);国家科技攻关计划课题(2003BA612A-01);中国地质调查局国土资源大调查项目(编号200420190004)资助成果。

摘　　要：川西是中国重要的稀有金属矿产资源基地,川西可尔因伟晶岩型稀有金属矿床位于松潘-甘孜造山带主体的中心部位,对该造山带的演化过程具有重要的示踪意义。本文对可尔因地区根则岩体中白云母微斜长石伟晶岩脉和党坝白云母钠长石锂辉石伟晶岩脉进行了40Ar／39Ar定年研究,其白云母40Ar／39Ar坪年龄分别为176．25± 0．14Ma和152．43±0．60Ma。结合前人对可尔因岩体的成因认识和K-Ar、Rb-Sr、U-Pb同位素定年结果,推断出在印支晚期-燕山早期,该地区经历了多期岩浆演化,且持续了较长的时间,而伟晶岩的稀有金属矿化发生在岩浆活动末期的相对稳定和封闭的环境中。这些地质现象说明,松潘-甘孜造山带在经历了印支末期-燕山早期的剧烈构造运动后,在150 Ma左右进入相对稳定发展的阶段,直至喜马拉雅运动造成地壳急剧隆升,这段稳定时期为各种成矿作用的发生提供了必要条件。Western Sichuan is an important area of rare metal resources in China. KeerYin pegrnatite type rare metal ore deposit is located at the center of the Songpan-Garze orogenic zone, stern Sichuan. To study it can trace the evolution of the Songpan-Garze orogenic zone. In this paper, ^40Ar/^39Ar plateau age of 176.25 ± 0. 14 Ma of muscovite from the muscovite-rnicrocline pegrnatite in Genze intrusive rock and the age of 152. 43 ± 0. 60 Ma from Dangba lithium deposit are gotten. Considering the genesis of the granites and published K-At, Rb-Sr, U-Pb isotope ages, it is concluded that in the late of Indosinian epoch and the early of Yanshanian epoch, large scale magrnations happened in Keeryin region, and lasted a long time. But rare metal mineralization took place in steady and close geologic environment in the late of magrnations. These geological phenomena showed that the Songpan-Garze orogenic zone evolved into stable period until the beginning of Himalayan movement. The stable period is ready for ore-forming of many type deposit.

关 键 词：^40Ar/^39Ar定年 稀有金属 伟晶岩型矿床 可尔因 松潘-甘孜造山带 

分 类 号：P618.2[天文地球—矿床学]