Further evidence of the complexity of the racemization process in fossil shells with implications for amino acid racemization dating

Journal Article · Wed Apr 01 04:00:00 EST 1987 · Geochim. Cosmochim. Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(87)90097-4· OSTI ID:6935531

Kimber, R W.L.; Griffin, C V

Simulated aging experiments with shells of Ostrea, Anadara and Katelysia spp from Modern, Holocene and Pleistocene marine sediments in southern Australia give further insight into the difficulties in using D/L ratios of amino acids for quantitative age determinations. Evidence is given that the progress of racemization, as monitored by changes in D/L ratios with time, is not only non-linear but also may be reversed, demonstrating a decrease in the observed degree of racemization. The observed changes in D/L ratio with time differ according to the age and the genus of shell, and the amino acid examined. Katelysia spp. gives less variable values than Ostrea or Anadara and similarly valine racemization and isoleucine epimerization are far less variable than aspartic acid racemization.

• Research Organization: CSIRO, Glen Osmond (Australia)
• OSTI ID: 6935531
• Journal Information: Geochim. Cosmochim. Acta; (United States), Journal Name: Geochim. Cosmochim. Acta; (United States) Vol. 51:4; ISSN GCACA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580100 -- Geology & Hydrology-- (-1989)
580400* -- Geochemistry-- (-1989)
AGE ESTIMATION
AMINO ACIDS
ASPARTIC ACID
AUSTRALASIA
AUSTRALIA
CARBOXYLIC ACIDS
CENOZOIC ERA
CHEMISTRY
FOSSILS
GEOCHEMISTRY
GEOLOGIC AGES
GEOLOGIC DEPOSITS
ORGANIC ACIDS
ORGANIC COMPOUNDS
QUATERNARY PERIOD
RACEMATES
RACEMIZATION
SEDIMENTS
SOUTH AUSTRALIA
STEREOCHEMISTRY
WEATHERING