Climatic Control of Riverine and Seawater Uranium-Isotope Ratios
Abstract
The large variation in the ratio of uranium-234 to uranium-238 (^(234)U/^(238)U) in rivers is not well understood, but may provide information about past weathering and rainfall and is important because it controls seawater (^(234)U/^(238)U). Here, we demonstrate the importance of physical weathering and rainfall for (^(234)U/^(238)U), using rivers from South Island, New Zealand. These data allow interpretation of an existing speleothem (^(234)U/^(238)U) record and suggest that New Zealand glacier advance 13,000 years ago was influenced by increased rainfall rather than by Younger Dryas–like cooling. A model of seawater (^(234)U/^(238)U) during glacial cycles indicates that rejection of corals based on modern (^(234)U/^(238)U) ± <0.01 is not merited and may reject the highest quality ages.
Additional Information
© 2004 American Association for the Advancement of Science. 27 April 2004; Accepted 7 July 2004. We thank the Gary Comer Fellowship program for financial support and N. Belshaw for help in the laboratory.Attached Files
Supplemental Material - Robinson_SOM.pdf
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Additional details
- Eprint ID
- 52264
- DOI
- 10.1126/science.1099673
- Resolver ID
- CaltechAUTHORS:20141202-103840474
- Gary Comer Fellowship
- Created
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2014-12-02Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field