Kinetic model options for interpretation of amino acid enantiomeric ratios in Quaternary mollusks: Comments on a paper by Kvenvolden et al. (1979)

Abstract

A comparison of linear (to D/L leucine of ca. 0.55) and non-linear (slowing of racemization rates by a factor of ca. 10 × after D/L leucine of ca. 0.25) model kinetics is presented in order to interpret amino acid enantiomeric ratio data in Holocene and Pleistocene marine mollusks from the Pacific coast of the United States. Linear model rate constants for well-dated Holocene and Pleistocene samples are not consistent with probable temperature histories or probable latitudinal differences in effective temperatures for these samples, using reasonable values for the activation energy of racemization. The non-linear model, with a much earlier transition from rapid to slow racemization rates, appears more consistent with available data. © 1981.