NEW CONSTRAINTS ON THE LA-138 BETA-DECAY CONSTANT BASED ON A GEOCHRONOLOGICAL STUDY OF GRANITES FROM THE YILGARN BLOCK, WESTERN-AUSTRALIA

被引：21

作者：

MAKISHIMA, A ^{[1
]}

NAKAMURA, E ^{[1
]}

AKIMOTO, S ^{[1
]}

CAMPBELL, IH ^{[1
]}

HILL, RI ^{[1
]}

机构：

[1] AUSTRALIAN NATL UNIV,RES SCH EARTH SCI,CANBERRA,ACT 2601,AUSTRALIA

来源：

CHEMICAL GEOLOGY | 1993年 / 104卷 / 1-4期

关键词：

D O I：

10.1016/0009-2541(93)90158-F

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

The beta-decay constant of La-138 has been geochronologically determined using Archean granites from the Yilgarn Block, Western Australia. Rb-Sr and Sm-Nd mineral isochron ages were obtained for the two granite samples, which are nearly identical with the ion microprobe U-Pb zircon ages. This agreement indicates that the closure date for these samples is the same, within analytical error, making them suitable for geochronological estimation of the beta-decay constant for La-138. Applying a new method of Ce isotope analysis, with analytical reproducibility of +/- 0.008%, La-Ce isotope data for the studied samples resulted in precise mineral isochrons. Based on these internal mineral isochrons and ages determined by other geological clocks, the beta-decay constant for La-138 was estimated to be (2.33 +/- 0.24).10(-12) a-1 (2sigma).

引用

页码：293 / 300

页数：8