Racemization dating definition

This paper explores the potential application of a new methodology of amino acid racemization (AAR) dating of shell middens and describes a simple protocol to test the suitability of different molluscan species.

This protocol provides a preliminary test for the presence of an intracrystalline fraction of proteins (by bleaching experiments and subsequent heating at high temperature), checking the closed system behaviour of this fraction during diagenesis.

Specific changes in its amino acid structure (racemization or epimerization) which occur at a slow, relatively uniform rate, are measured after the organism's death.The basis for the technique is the fact that almost all amino acids change from optically active to optically passive compounds (racemize) over a period of time.Results obtained in this study indicate that the application of this new method of AAR dating of shells has the potential to aid the geochronological investigation of shell mounds in different areas of the world.Shell midden sites, found throughout the world, provide a range of important archaeological information, including the use of coastal resources, consumption practices and human impact on the environment.SYNONYMS OR RELATED TERMS: amino-acid dating; aminostratigraphy; amino-acid racemization, amino acid racemization CATEGORY: technique DEFINITION: A method of absolute (chronometric) dating which is hoped to fill the gap between radiocarbon dates and potassium-argon dates.

It is used for human and animal bone and other organic material.Well to some extent maybe but it reveals a very simplistic understanding of dating techniques and of science itself.He is one example I have offered in the past to this exact comment above: That the earth is assumed to be billions of years old cannot be considered an a-priori assumption given that this this age for the earth has only been estimated in the last 100 years.Furthermore, to object to the constancy of radiometric decay would not go far in explaining why in the vast majority of cases different dating methods that work in operate in different ways under different physical assumptions result in ages that are for the most part highly convergent.Let us take a lesser known form of dating as an example.SYNONYMS OR RELATED TERMS: chronometric dating; absolute dates; absolute chronology; absolute age determination (antonym: relative dating)CATEGORY: chronology; technique DEFINITION: The determination of age with reference to a specific time scale, such as a fixed calendrical system or in years before present (B.