Strontium Isotopic Composition in Arctic Pleistocene and Pliocene Marine Sediments
The primary goal of the research was to use 87Sr/86Sr as a geochronometer in Arctic Ocean sediments. This attempt was unsuccessful because the analytical precision of the analysis (+/-0.000010) was insufficient to differentiate the expected change in oceanic 87Sr/86Sr. New data published after the s...
Main Authors: | , |
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Format: | Text |
Language: | English |
Published: |
1997
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Online Access: | http://www.dtic.mil/docs/citations/ADA348828 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA348828 |
Summary: | The primary goal of the research was to use 87Sr/86Sr as a geochronometer in Arctic Ocean sediments. This attempt was unsuccessful because the analytical precision of the analysis (+/-0.000010) was insufficient to differentiate the expected change in oceanic 87Sr/86Sr. New data published after the submission of this proposal indicated that the change was on 0.000025, half that of previously published data. However, a study of the strontium isotopic composition of foraminifera from the Arctic implied that there is enrichment of radiogenic strontium in the Arctic halocline. Although the mean values are statistically different in the Arctic Ocean and the South Atlantic, contamination by clay minerals in the Arctic cannot be ruled out. A simple box model indicates that some enrichment of strontium in surface waters must occur, but the amount is very sensitive to the strontium isotopic composition of Arctic rivers. Models using the most recent riverine data do not produce the observed enrichment. |
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