Climate-correlated variations in seawater 187Os/188Os over the past 200,000 yr; evidence from the Cariaco Basin, Venezuela

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doi: 10.1016/j.epsl.2007.08.033
Author(s): Oxburgh, Rachel; Pierson-Wickmann, Anne-Catherine; Reisberg, Laurie; Hemming, Sidney R.
Author Affiliation(s): Primary:
University of Edinburgh, School of GeoSciences, Edinburgh, United Kingdom
Centre de Recherches Pétrographiques et Géochimiques, France
Lamont-Doherty Earth Observatory, United States
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, 263(3-4), p.246-258. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. 46 refs.; illus., incl. 2 tables, sketch maps
Summary: A high resolution record of seawater osmium isotopic composition (35 samples over the past 191,000 yr) has been obtained from sediments from Ocean Drilling Program (ODP) Leg 165 Site 1002 in the Cariaco Basin, Venezuela. Strong correlations are observed between 187Os/188Os and both the local and global oxygen isotopic records, with less radiogenic values observed during glacial intervals. In conjunction with previous analyses of sediments from the East Pacific Rise, the Santa Barbara Basin, and the Japan Sea, the data demonstrate conclusively that there have been ocean-wide changes in seawater 187Os/188Os over the Pleistocene. Global seawater excursions to relatively unradiogenic 187Os/188Os, indicating decreased continental inputs, occur during cold intervals, times of increased aridity and increased ice cover of old (radiogenic) continental masses. The data thus indicate a direct climatic control on chemical weathering rates and/or composition of weathering products on a glacial-interglacial timescale. Abstract Copyright (2007) Elsevier, B.V.
Year of Publication: 2007
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 24 Surficial Geology, Quaternary Geology; Atlantic Ocean; Cariaco Basin; Caribbean Sea; Cenozoic; Climate change; East Pacific; East Pacific Rise; Erosion; Glacial-interglacial cycles; Isotope ratios; Isotopes; Leg 165; Metals; North Atlantic; ODP Site 1002; Ocean Drilling Program; Os-188/Os-187; Osmium; Pacific Ocean; Platinum group; Quaternary; Sea water; South America; Stable isotopes; Upper Quaternary; Venezuela; Weathering; Weathering rates
Coordinates: N104222 N104222 W0651011 W0651011
Record ID: 2008062964
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands