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A critical evaluation of the application of amino acid racemization to geochronology and geothermometryAttempts have been made to determine the age of biological samples by measuring the racemization of amino acids in protein samples. The pitfalls and inherent complications in diagenetic racemization studies are reviewed, and recent advances in improving techniques are outlined. Methodological topics include isolation of amino acids from geological samples, resolution of amino acid enantiomers, and the effects of acid hydrolysis. The theory and kinetics of amino acid racemization are discussed with attention to the derivation of the rate expression for amino acid racemization, isoleucine and the equilibrium constant, the mechanism of amino acid racemization, the racemization of 'bound' versus 'free' amino acids, and factors affecting the racemization rates of free amino acids in aqueous solution. Applications of amino acid racemization kinetics to geochronology is considered with reference to shells, marine sediments, and bones. Potential complications include heating and diagenesis, diagenetic formation of amino acids, the effect of clays, species effect, and contamination.
Document ID
19780030773
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Williams, K. M.
(Utah State Univ. Logan, UT, United States)
Smith, G. G.
(Utah State University of Agriculture and Applied Science, Logan, Utah, United States)
Date Acquired
August 9, 2013
Publication Date
August 1, 1977
Publication Information
Publication: Origins of Life
Volume: 8
Subject Category
Life Sciences (General)
Accession Number
78A14682
Funding Number(s)
CONTRACT_GRANT: NSG-7038
Distribution Limits
Public
Copyright
Other

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