Stratigraphic potential of amino acid ratios in Pleistocene terrestrial gastropods: an example from West-Central Indiana, USA

Autor: Barry B. Miller, William D. McCoy, Ned K. Bleuer
Rok vydání: 2008
Předmět:
Zdroj: Boreas. 16:133-138
ISSN: 1502-3885
0300-9483
DOI: 10.1111/j.1502-3885.1987.tb00765.x
Popis: Miller, Barry B., McCoy, William D. & Bleuer, Ned K. 1987 06 01: Stratigraphic potential of amino acid ratios in Pleistocene terrestrial gastropods: an example frpm West-Central Indiana, USA. Boreas, Vol. 16, pp. 133–138. Oslo. ISSN 0300–9483. The terrestrial gastropods Catinella spp., Stenotrema leai and Hendersonia occulta have been studied from 10 Wisconsinan and pre-Wisconsinan sites in west-central Indiana to determine if amino acid racemization values from these fossils would have stratigraphic utility in this area. The ages of the samples range from about 20,000 years B.P. for materials collected from radiocarbon-dated deposits of the Trafalgar Formation, to >730,000 years B.P. for fossils obtained from magnetically reversed silts of the Jessup and Banner Formations. The shell samples have yielded four groups or aminozones based on the ratio of D-alloisoleucine to L-isoleucine in both the free fraction and the total acid hydrolysate from the shell samples. The results of this preliminary study appear to be consistent with the previously assumed age of the strata from which the fossils were collected and suggest that the technique has great promise as a chronostratigraphic tool in Quaternary sequences that contain terrestrial pulmonate and prosobranch gastropods.
Databáze: OpenAIRE