Climatic control of riverine and Seawater uranium-isotope ratios

L F Robinson, G M Henderson, L Hall, I Matthews

Research output: Contribution to journalArticle (Academic Journal)peer-review

95 Citations (Scopus)

Abstract

The large variation in the ratio of uranium-234 to uranium-238 (U-234/U-238) in rivers is not well understood, but may provide information about past weathering and rainfall and is important because it controls seawater (U-234/U-238). Here, we demonstrate the importance of physical weathering and rainfall for (U-234/U-238), using rivers from South Island, New Zealand. These data allow interpretation of an existing speleothem (U-234/U-238) 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 (U-234/U-238) during glacial cycles indicates that rejection of corals based on modern (U-234/U-238) +/- < 0.01 is not merited and may reject the highest quality ages.

Original languageEnglish
Pages (from-to)851-854
Number of pages4
JournalScience
Volume305
Issue number5685
Publication statusPublished - 6 Aug 2004

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