Raman spectroscopy of fossil bioapatite - A proxy for diagenetic alteration of the oxygen isotope composition

Date
2011
Authors
Thomas D.B.
McGoverin C.M.
Fordyce R.E.
Frew R.D.
Gordon K.C.
Journal Title
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Volume Title
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Abstract
Fossil bioapatite may yield biogeochemical signals of paleoenvironments captured by living organisms. Bioapatite may be diagenetically altered, however, with ions added or removed post-mortem; such change is typically assessed using destructive and demanding techniques. Here, Raman spectroscopy is used as a rapid and non-destructive way to identify significant diagenetic alteration of fossil bioapatite. We found spectral parameters of phosphate symmetric stretching (μ1-PO43-) to be very sensitive to variations in apatite chemistry, particularly with respect to common diagenetic components (CO32-, F-, Sr2+). The Raman spectral parameters were subsequently applied to a set of modern (biogenic) and geologic (magmatic) apatite samples as potential endmembers for diagenetic alteration. Raman spectra were also collected from enamel and dentin (respectively resistant vs. alteration-prone) of fossil teeth. Phosphate-oxygen isotopic values from the same enamel-dentin samples were used as an index of alteration and provided definition of Raman spectral parameters as relates to diagenetic alteration. Diagenetically altered samples were characterised by spectra with μ1-PO43- widths (at half maximum height) less than 13.0cm-1, and μ1-PO43- band positions greater than 964.7cm-1. Raman spectroscopy is shown to have potential as a tool for pre-screening fossil apatite samples before further analyses. © 2011 Elsevier B.V.
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Citation
Palaeogeography, Palaeoclimatology, Palaeoecology
310
02-Jan
http://www.scopus.com/inward/record.url?eid=2-s2.0-80052756037&partnerID=40&md5=8ccd8ba23d14dd4748b199fd2cd0216e
URI
http://hdl.handle.net/10019.1/17069
Collections
Stellenbosch University - Scopus Publications