Browsing by Author "Barham, AJ"

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    Marine carbon reservoir variability in Torres Strait: preliminary results of AMS dating of live-collected shell specimens.
    (International Union for Quaternary Research, 2007-07) Ulm, S; Barham, AJ; David, B; Jacobsen, GE; McNiven, IJ; Petchey, F; Rowland, MJ
    Despite routine dating of marine shell by Quaternary scientists in the Torres Strait region, no systematic evaluation of the applicability of the recommended DeltaR value has been undertaken. This value can be shown to be problematic. It is based on only three samples from Torres Strait and two from the west coast of Cape York Peninsula, together spanning 125±60 to -14±60 years; the samples are from different oceanographic provinces; the dated taxa are not amongst those commonly dated by contemporary researchers; and all of the dates were obtained over 20 years ago before the advent of high precision AMS dating. This project attempts to address this deficiency through the dating of a suite of well-provenanced live-collected shell specimens using the high precision ANTARES AMS facilities at ANSTO. Dated samples are largely derived from a unique assemblage of well-documented live-collected shell specimens in the Australian Museum from Murray Island and Albany Passage collected by Charles Hedley in August-October 1907, supplemented by smaller collections from elsewhere in Torres Strait. Sample selection focused on suspension-feeders (Arcidae, Mesodesmatidae, Veneridae), although carnivores (Volutidae), herbivores/omnivores (Neritidae) and algae grazers (Trochidae) were included to examine inter-taxa variability. Preliminary results help establish more robust regional DeltaR values for the region based on shellfish commonly dated by Quaternary scientists and allow examination of localised variability in DeltaR values. These findings have broad implications for refining chronologies in coastal archaeology and geomorphology in the Torres Strait region, including studies of sea-level change, reef and coral cay development, coastal dune sequences, storm event frequency and archaeological trends.