| Summary: | The neodymium isotopic composition of marine precipitates is increasingly recognized as a powerful tool for identifying changes in ocean circulation and mixing on million year to millennial timescales. Unlike nutrient proxies such as δ^(13)C or Cd/Ca, Nd isotopes are not thought to be altered in any significant way by biological processes, and thus they can serve as a quasi-conservative water mass tracer. However, the application of Nd isotopes in understanding the role of thermohaline circulation in rapid climate change is currently hindered by the lack of direct constraints on the signature of the North Atlantic end-member through time. Here we present the first results of Nd isotopes measured in U-Th-dated deep-sea corals from the New England seamounts in the northwest Atlantic Ocean. Our data are consistent with the conclusion that the Nd isotopic composition of North Atlantic deep and intermediate water has remained nearly constant through the last glacial cycle. The results address long-standing concerns that there may have been significant changes in the Nd isotopic composition of the North Atlantic end-member during this interval and substantiate the applicability of this novel tracer on millennial timescales for paleoceanography research. © 2006 American Geophysical Union. Received 17 March 2006; revised 8 July 2006; accepted 19 July 2006; published 25 November 2006. This study was supported by the Comer Science and Education Foundation and the Vetlesen Foundation Climate Center at LDEO. We thank Marty Q. Fleisher, N. Gary Hemming, Anna Cipriani, Allison M. Franzese, and Jennifer M. Cole for their help in keeping the labs and the mass specs running smoothly. We also thank two anonymous reviewers for their productive comments. This is Lamont contribution 6977. Published - 2006PA001294.pdf
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