摘要
本文对铼—锇同位素体系的基础原理进行了介绍,并提出了铂—锇同位素体系及其与铼—锇同位素体系进行联合应用的设想,在铼—锇和铂—锇的联合体系中,地幔作用过程及地壳—地幔之间的相互作用,将由^(187)Os/^(188)Os/^(186)Os/^(188)Os比值及其相应的γ_(UMR)~T(^(187)Os)和γ_(UMR)~T(^(186)Os)参数来进行描述。这一对比值和参数对地幔作用过程及地壳—地幔之间相互作用的描述,将会比目前所采用的单一^(187)Os/^(188)Os比值所作的描述更为深刻和准确。同时,在这两种同位素的联合体系中,由于铂及锇都聚集于地幔中,不易受地壳物质的污染,因而即使在铼—锇同位素体系受到地壳物质污染的情况下,我们仍可根据两个或两个以上的不合谐年龄值,通过与联合体系的合谐年龄曲线相交,而得到合谐年龄值。
This article addresses the feasibility of the Pt-Os system and coupled Re-Os and Pt-Os systematics. The Pt-Os system is feasible because of the existence of materials with high Pt/Os ratios. in the coupled Re-Os and Pt-Os systematics, the mantle processes and the interactions between the crust and mantle should be described by 187Os/188Os, 186Os/188Os rations, γTUMR(187Os) and γTUMR (186Os)parameters. These two ratios and parameters would more precisely reveal the mantle processes and the interactions between the crust and the mantle than a single ratio does. In addi-tion, 190Pt-186Os system is not as easily contaminated by crustal materials as the 187Re-187Os system because both Pt and Os are concentrated in the mantle. Therefore, in the coupled Re-Os and Pt-Os systematics, a date wffl be obtained according to the 186Os/190Pt-187Os/187Re concordia diagram as long as the 190Pt-186Os system remains dosed even if the 187Re-187Os sys-tem has been contaminated by crustal materials.
出处
《地球科学（中国地质大学学报）》
EI
CAS
CSCD
北大核心
1994年第4期519-528,共10页
Earth Science-Journal of China University of Geosciences
基金
自然科学基金资助项目(中国)
关键词
铼
饿
铂
同位素体系
联合体系
Re-Os system,Pt-Os system,coupled Re-Os and Pt-Os systematics,γTUMR (187Os) and γTUMR (186Os) parametere, Re-Os and Pt-Os concordia diagram.
