Publication Date:
2007-09-29
Description:
High-resolution chemostratigraphy reveals an episode of enrichment of the redox-sensitive transition metals molybdenum and rhenium in the late Archean Mount McRae Shale in Western Australia. Correlations with organic carbon indicate that these metals were derived from contemporaneous seawater. Rhenium/osmium geochronology demonstrates that the enrichment is a primary sedimentary feature dating to 2501 +/- 8 million years ago (Ma). Molybdenum and rhenium were probably supplied to Archean oceans by oxidative weathering of crustal sulfide minerals. These findings point to the presence of small amounts of O2 in the environment more than 50 million years before the start of the Great Oxidation Event.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Anbar, Ariel D -- Duan, Yun -- Lyons, Timothy W -- Arnold, Gail L -- Kendall, Brian -- Creaser, Robert A -- Kaufman, Alan J -- Gordon, Gwyneth W -- Scott, Clinton -- Garvin, Jessica -- Buick, Roger -- New York, N.Y. -- Science. 2007 Sep 28;317(5846):1903-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA. anbar@asu.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17901330" target="_blank"〉PubMed〈/a〉
Keywords:
Australia
;
Geologic Sediments/*chemistry
;
Isotopes/analysis
;
Molybdenum/analysis
;
Oceans and Seas
;
Osmium/analysis
;
Oxidation-Reduction
;
*Oxygen/analysis
;
Rhenium/analysis
;
Seawater/chemistry
;
Sulfur/analysis
;
Sulfur Isotopes/analysis
;
Temperature
;
Uranium/analysis
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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