The Open UniversitySkip to content
 

The rhenium–osmium isotope system: applications to geochronological and palaeoenvironmental problems

Cohen, Anthony S. (2004). The rhenium–osmium isotope system: applications to geochronological and palaeoenvironmental problems. Journal of the Geological Society, 161(4) pp. 729–734.

URL: http://jgs.geoscienceworld.org/cgi/content/abstrac...
DOI (Digital Object Identifier) Link: http://dx.doi.org/10.1144/0016-764903-084
Google Scholar: Look up in Google Scholar

Abstract

The rhenium–osmium (Re–Os) isotope system occupies a unique position amongst commonly used radiogenic parent–daughter isotope pairs on account of its siderophilic geochemical characteristics. Re and Os are also concentrated from seawater in organic-rich sediments and have been used to obtain absolute ages for the deposition of marine mudrock successions directly. Additionally, Re–Os analyses of ancient mudrocks have provided the best means so far of determining temporal changes in the Os-isotope composition of pre-Cenozoic seawater. The seawater Os-isotope record has yielded valuable information about several major episodes of past environmental change, and is particularly powerful when used in conjunction with other marine isotopic tracers such as carbon and strontium. The present contribution reviews some recent developments in the application of the Re–Os isotope system to geochronological and palaeoenvironmental problems in the Mesozoic and earlier. New results show that the Os-isotope composition of Callovian seawater (c. 160 Ma ago) was very unradiogenic (187Os/188Os 0.26) at the same time that the seawater Sr-isotope curve recorded its lowest value for the Phanerozoic, indicating that global continental weathering rates were very low at c. 10–15% of today's levels.

Item Type: Journal Article
ISSN: 0016-7649
Keywords: Re–Os; Mesozoic; mudrock; black shale; organic carbon;
Academic Unit/Department: Science > Environment, Earth and Ecosystems
Interdisciplinary Research Centre: Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
Item ID: 10606
Depositing User: Users 2315 not found.
Date Deposited: 17 Apr 2008
Last Modified: 02 Dec 2010 20:07
URI: http://oro.open.ac.uk/id/eprint/10606
Share this page:

Altmetrics

Scopus Citations

Actions (login may be required)

View Item
Report issue / request change

Policies | Disclaimer

© The Open University   + 44 (0)870 333 4340   general-enquiries@open.ac.uk