The use of foraminiferal uranium/calcium ratios as an indicator of changes in seawater uranium content Public Deposited

http://ir.library.oregonstate.edu/concern/defaults/ht24wm03z

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • We examine the utility of the uranium (U) content of planktonic foraminifera tests as an indicator of past changes in seawater U content. The U/Ca ratio in foraminifera from Atlantic and Caribbean cores in constant in the Holocene and decreases by ~25% during the last glacial period. Magnesium/calcium (Mg/Ca) ratios of the same samples show similar trends. While the timing of the U/Ca changes appears to be associated with glacial-interglacial changes, the magnitude of the change is too large to be caused by variations in the extent of anoxic or suboxic sediments or by changes in riverine input. We assume that the same process produced changes in both U/Ca and Mg/Ca ratios because of a strong correlation between the two ratios. Partial dissolution of the calcite is ruled out, because we observe the same changes in well-preserved cores from basins with opposite dissolution histories. We also reject exchange between foraminiferal and pore water U because of the oxic depositional environment of both cores and because of the consistency in the U/Ca trends from cores in different parts of the ocean. We suggest that the observed foraminiferal U/Ca and Mg/Ca trends may be the result of a temperature effect on the incorporation of these metals. If this is true, it introduces the possibility of a new paleotemperature indicator but complicates the use of U/Ca ratios in planktonic foraminifera tests as an indicator of past seawater U changes.
Resource Type
Date Available
Date Issued
Citation
  • Russell, A. D., Emerson, S., Mix, A. C., Peterson, L. C. The use of foraminiferal uranium/calcium ratios as an indicator of changes in seawater uranium content. (1996) Paleoceanography, Vol. 11, No. 6, Pages 649-663,
Series
Rights Statement
Funding Statement (additional comments about funding)
Publisher
Language
Replaces
Additional Information
  • description.provenance : Approved for entry into archive by Linda Kathman(linda.kathman@oregonstate.edu) on 2010-03-03T14:13:34Z (GMT) No. of bitstreams: 1 Russell et al Paleo 1996.pdf: 1288741 bytes, checksum: 2c4d16f96860c30930c17fbad7d91b54 (MD5)
  • description.provenance : Submitted by Linda Lamb (llamb@coas.oregonstate.edu) on 2010-03-02T19:36:20Z No. of bitstreams: 1 Russell et al Paleo 1996.pdf: 1288741 bytes, checksum: 2c4d16f96860c30930c17fbad7d91b54 (MD5)
  • description.provenance : Made available in DSpace on 2010-03-03T14:13:34Z (GMT). No. of bitstreams: 1 Russell et al Paleo 1996.pdf: 1288741 bytes, checksum: 2c4d16f96860c30930c17fbad7d91b54 (MD5) Previous issue date: 1996-12
ISSN
  • 0883-8305

Relationships

In Administrative Set:
Last modified: 07/24/2017

Downloadable Content

Download PDF
Citations:

EndNote | Zotero | Mendeley

Items