DOI: 10.1016/j.palaeo.2015.08.019
论文题名: Evidence for weathering and volcanism during the PETM from Arctic Ocean and Peri-Tethys osmium isotope records
作者: Dickson A.J. ; Cohen A.S. ; Coe A.L. ; Davies M. ; Shcherbinina E.A. ; Gavrilov Y.O.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2015
卷: 438 语种: 英语
英文关键词: Arctic Ocean
; Osmium isotopes
; Paleocene-Eocene Thermal Maximum
; Peri-Tethys
; Volcanism
; Weathering
英文摘要: Sudden global warming during the Paleocene-Eocene Thermal Maximum (PETM, 55.9. Ma) occurred because of the rapid release of several thousand gigatonnes of isotopically light carbon into the oceans and atmosphere; however, the cause of this release is not well understood. Some studies have linked carbon injection to volcanic activity associated with the North Atlantic Igneous Province (NAIP), while others have emphasised carbon cycle feedbacks associated with orbital forcing. This study presents the osmium isotope compositions of mudrocks that were deposited during the PETM at four locations (one from the Arctic Ocean, and three from the Peri-Tethys). The Os-isotope records all exhibit a shift of similar magnitude towards relatively radiogenic values across the PETM. This observation confirms that there was a transient, global increase in the flux of radiogenic Os from the weathering of continental rocks in response to elevated temperatures at that time. The tectonic effects of NAIP volcanic emplacement near the onset of the PETM is recorded by anomalously radiogenic Os-isotope compositions of PETM-age Arctic Ocean samples, which indicate an interval of hydrographic restriction that can be linked tectonic uplift due to hotspot volcanism in the North Atlantic seaway. The Peri-Tethys data also document a transient, higher flux of unradiogenic osmium into the ocean near the beginning of the PETM, most likely from the weathering of young mafic rocks associated with the NAIP. These observations support the hypothesis that volcanism played a major role in triggering the cascade of environmental changes during the PETM, and highlight the influence of paleogeography on the Os isotope characteristics of marine water masses. © 2015 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68808
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Environment, Earth and Ecosystems, The Open University, Walton Hall, Milton Keynes, United Kingdom; Geological Institute, Russian Academy of Sciences, Pyzhevsky 7, Moscow, Russian Federation
Recommended Citation:
Dickson A.J.,Cohen A.S.,Coe A.L.,et al. Evidence for weathering and volcanism during the PETM from Arctic Ocean and Peri-Tethys osmium isotope records[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2015-01-01,438