(Table 1) Strontium isotope ratios of planktonic foraminifera and ostracoda from ODP Hole 120-748B on the Kerguelen Plateau, Indian Ocean, supplement to: Zachos, James C; Opdyke, Bradley N; Quinn, Terrence Michael; Jones, Charles E; Halliday, Alex N (1999): Early cenozoic glaciation, antarctic weathering, and seawater 87Sr/86Sr: is there a link? Chemical Geology, 161(1-3), 165-180
Stable and radiogenic isotopic and sedimentological data from sub-Antarctic deep sea sediment cores reveal a temporal link between changes in seawater 87Sr/86Sr ratios and major episodes of late Eocene-early Oligocene climate change. The 87Sr/86Sr records show two major inflections, one at 38-39 Ma...
Main Authors: | , , , , |
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Format: | Dataset |
Language: | English |
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PANGAEA - Data Publisher for Earth & Environmental Science
1999
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Subjects: | |
Online Access: | https://dx.doi.org/10.1594/pangaea.695370 https://doi.pangaea.de/10.1594/PANGAEA.695370 |
Summary: | Stable and radiogenic isotopic and sedimentological data from sub-Antarctic deep sea sediment cores reveal a temporal link between changes in seawater 87Sr/86Sr ratios and major episodes of late Eocene-early Oligocene climate change. The 87Sr/86Sr records show two major inflections, one at 38-39 Ma near the middle/late Eocene boundary, followed by another at 33.4 Ma. Similarly, the oxygen isotope, ice-rafted debris, and clay assemblage records indicate two important climatic events: the appearance of alpine glaciers and/or small ice-sheets on Antarctica in the late Eocene at 38-39 Ma, followed by a rapid transition to larger and more permanent temperate ice-sheets in the early Oligocene at 33.4 Ma. Moreover, during the early Oligocene 30-33 Ma. three to four inferred peaks in glacial activity appear to coincide with subtle steps in the 87Sr/86Sr record. The coupled variations in climate and seawater Sr isotope ratios during the Eocene/Oligocene imply a strong causal link between the two. Either changes in climate directly influenced patterns of continental weathering and hence seawater chemistry, and/or a tectonic event e.g., uplift.as reflected in weathering and seawater chemistry triggered relatively abrupt changes in global climate. |
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