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High Resolution Records of Environmental Conditions from Mollusc Shells: Exploiting the Potential of Microbeam Instruments: Renee K. Takesue


Project Title: High Resolution Records of Environmental Conditions from Mollusc Shells: Exploiting the Potential of Microbeam Instruments
Mendenhall Fellow: Renee K. Takesue, (650) 329-5093, rtakesue@usgs.gov
Duty Station: Menlo Park
Start Date: March 28, 2002
Education: Columbia University, 2002 - Chemical Oceanography (major); Paleoceanography, Atmospheric Science (minors)
Research Advisor: Charles Bacon, (650) 329-5246, cbacon@usgs.gov

Project Description: Two key characteristics make mollusc shells promising archives of environmental records: first, shell chemistry is influenced by variables such as salinity, temperature, and ambient water chemistry; second, shell deposition is nearly continuous. These combined qualities provide an exciting opportunity to reconstruct high-resolution environmental records using a material that occurs in a wide range of coastal and marine environments as well as in the geologic record. The ability to measure environmentally-sensitive elements/isotopes in growth-banded carbonates at extremely high spatial (and thus temporal) resolution has only recently been realized with the development of high-resolution mass spectrometers coupled to solid state micro-sampling systems. (strikethrough: My) Renee's goal is to develop this tool in conjunction with ongoing monitoring programs in San Francisco Bay/Estuary, and to use it to construct high (temporal)-resolution records of environmental conditions/change. A well-characterized, fast-growing mollusc, Potamocorbula amurensis, has been chosen for this approach since it may yield records with sub-weekly time resolution. Variations over such a fine time scale may additionally allow investigations into the nature of short-term metal bioaccumulation in P. amurensis, which is a biosentinel species for natural and anthropogenic heavy metal enrichments in SF Bay/Estuary.

References
Takesue, R.K., Bacon, C.R., and Thompson, J.K., 2008, Influences of organic matter and calcification rate on trace elements in aragonitic estuarine bivalve shells: Geochimica et Cosmochimica Acta, v. 72, p. 5431–5445.


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Last modified: 16:08:33 Thu 13 Dec 2012