东天山接触交代型铁矿成矿时代的确定及其意义  

METALLOGENIC AGE AND SIGNIFICANCE OF CONTACT METASOMATIC TYPE IRON DEPOSITS IN THE EASTERN TIANSHAN

作　　者：邓松涛[1] 郭召杰[1] 张志诚[1] 

机构地区：[1]北京大学造山带与地壳演化教育部重点实验室,北京100871

出　　处：《地质与勘探》2006年第6期17-20,共4页Geology and Exploration

基　　金：国家重点基础研究规划项目(编号:2001CB409804)资助

摘　　要：通过对东天山接触交代型铁矿中透闪石单矿物进行40Ar/39Ar年龄测定,获得坪年龄(387.21±0.68)Ma和等时线年龄(389.65±1.46)Ma。初步认为,此类接触交代型铁矿的成矿时代为387Ma左右。结合区域构造背景,可以认为,在早古生代东天山处于洋壳俯冲—消减产生的陆缘弧环境下,大规模构造岩浆活动是前寒武系中铁元素富集的主要动力,也是形成接触交代型铁矿的主要控制因素之一。By ^40Ar/^39Ar dating for trenolite of contact metasomatic type iron deposits in the eastern Tianshan, this paper has yielded plateau age at （387.21±0.68）Ma and isochron age at （389.65 ±1.46）Ma. Metallogenic age of this kind of iron deposits was incipiently considered to be at about 387Ma. Combined with regional tectanie backgrounds, it is proposed that the eastern Tianshan was a continental arc in the early Paleozoic which resulted from the subduetion of the paleo -ocean crust. Continental are magmatisrn was the main dynamics for iron enrichment, and also one of the dominant factors for contact metasomatie type iron deposits.

关 键 词：铁矿^40Ar/^39Ar定年 成矿时代 陆缘弧 

分 类 号：P618.31[天文地球—矿床学]