金红石U-Pb同位素定年技术研究  

Rutile U-Pb Isotopic Dating Methodology

作　　者：周红英[1] 李怀坤[1] 崔玉荣[1] 耿建珍[1] 张健[1] 李惠民[1] 

机构地区：[1]中国地质调查局天津地质矿产研究所,天津300170

出　　处：《地质学报》2013年第9期1439-1446,共8页Acta Geologica Sinica

基　　金：国土资源部公益性行业科研专项(编号:201011027)资助的成果

摘　　要：本文系统阐述了金红石U-Pb同位素定年的同位素稀释热电离质谱法（ID-TIMS）和激光烧蚀多接收器电感耦合等离子体质谱法（LA-MC-ICP-MS）两种方法,讨论了这两种方法的优点和局限性。利用LA-MCICP-MS验证了山西代县洪塘金红石矿区金红石的U-Pb同位素年龄的均一性;利用ID-TIMS对洪塘矿区金红石进行了U-Pb同位素精确定年,获得~207Pb/~206Pb表面年龄加权平均值：1806±2 Ma（MSWD=2.3,n=6）,不一致线的上交点年龄：1808±7Ma（MSWD=0.20,n=6）;并对金红石ID-TIMS U-Pb同位素测年和LA-MC-ICP-MS UPb同位素测年结果进行了对比研究。利用高精度的ID-TIMS U-Pb同位素测年和LA-MC-ICP-MS U-Pb同位素测年方法均有望获得准确可靠的金红石形成年龄。Rutile ID-TIMS and LA-MC-ICP MS U-Pb isotopic dating methods are elaborated systematically in this paper. The advantage and the limitation of the two methods are discussed respectively. Rutile from I）aixian, Shanxi Province were first analyzed using LA-MC-ICP MS method to check the U-Pb age homogeneity, and then dated precisely by means of ID TIMS method, yielding a weighted 207pb/206 Pb average age of 1805~2 Ma（MSWD--2. 3,n=6）and an upper interseption age of 1808±7Ma（MSWD-- 0.20,n=6）. The rutile U Pb isotopic dating results by ID-TIMS and in situ methods are comparatively studied in this paper. It is demonstrated that precise and reliable rutile U-Pb ages can be obtained by means of both ID-TIMS and I.A MC ICP MS methods.

关 键 词：金红石 U-PB同位素定年 ID-TIMS LA-MC-ICP-MS 山西代县洪塘 

分 类 号：P597.3[天文地球—地球化学]