Amino Acid Racemization
Amino acid racemization (AAR) dating estimates the age of biogenic materials such as mollusc shell, ostrich eggshell, bone, and teeth from the slow chemical conversion of amino acids from one mirror-image form to the other after an organism dies. Living tissue builds proteins almost entirely from left-handed (L) amino acids, but after death these gradually interconvert toward an equilibrium mixture of left- and right-handed (D) forms, so the measured ratio of D to L rises predictably with time. Because the reaction is a temperature-dependent chemical process rather than a radioactive decay, AAR is fundamentally a kinetic clock that must be calibrated against an independently dated reference and corrected for the sample's thermal history. Reviewed for archaeology by Johnson and Miller and covered as a standard chronometric tool in Renfrew and Bahn's textbook, it offers a rapid, inexpensive way to date or correlate deposits across the Quaternary, well beyond the radiocarbon range.
Record di origine
Citazioni copiate testualmente dal record di origine del metodo. Non si inferisce alcuna verifica a livello di affermazione da esse.
- Johnson, B. J., & Miller, G. H. (1997). Archaeological Applications of Amino Acid Racemization. Archaeometry, 39(2), 265-287. · DOI 10.1111/j.1475-4754.1997.tb00806.x
- Renfrew, C., & Bahn, P. (2016). Archaeology: Theories, Methods, and Practice (7th ed.). Thames & Hudson. · ISBN 9780500292105
Affermazioni curate
Affermazioni persistite nel registro delle evidenze, ciascuna con la propria valutazione.
Questa vista non inventa una valutazione dell'affermazione quando il registro non ne ha.
Metodi correlati
Generato dal grafo dei metodi e mostrato come relazioni suggerite dalla macchina — nessuna affermazione di evidenza viene inferita.