THE OSMIUM ISOTOPIC COMPOSITION OF ORGANIC-RICH MARINE-SEDIMENTS

被引：116

作者：

RAVIZZA, G

TUREKIAN, KK

机构：

[1] Department of Geology and Geophysics, Yale University, New Haven

来源：

EARTH AND PLANETARY SCIENCE LETTERS | 1992年 / 110卷 / 1-4期

关键词：

D O I：

10.1016/0012-821X(92)90034-S

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 osmium (Os) concentration and Os-187/Os-186 ratio of several recent, marine, organic-rich sediment samples from three widely separated sites have been measured. Os concentrations range from 0.095 to 0.212 ppb and Os-187/Os-186 ratios range from 8.2 to 8.9. The calculated fraction of hydrogenous Os exceeds 78% in all samples. Thus, the Os-187/Os-186 ratio of these samples reflects Os isotopic composition of seawater. The small range in measured Os-187/Os-186 ratio indicates that the Os isotopic composition at these sites is fairly homogeneous. The large magnitude of the Os burial flux at these sites indicates the Os burial in association with organic-rich sediments is an important sink in the marine cycle of Os. These data also suggest that ancient organic-rich sediments may provide a record of past variations in the Os isotopic composition of seawater.

引用

页码：1 / 6

页数：6

共 21 条

[11] OS-187 OS-186 IN MANGANESE NODULES AND THE CRETACEOUS-TERTIARY BOUNDARY [J].