Baseline bioavailable strontium and oxygen isotope mapping of the Adelaide Region, South Australia. (December 2020)

• Record Type: Journal Article
• Authors: Rippon, Lee; Rollog, Mark; Bruce, David; Farkas, Juraj; Pate, F. Donald; Owen, Timothy; Lucas, Teghan; McCallum, Stuart; Moffat, Ian
• Is Part Of: Journal of archaeological science. Volume 34:Part A(2020)
• Publication Date: 2020-12
• Subjects: Strontium Isotopes -- Oxygen Isotopes -- Provenance -- Archaeology -- South Australia; Archaeology -- Periodicals; Archaeology -- Research -- Periodicals; 930.1
• DOI: 10.1016/j.jasrep.2020.102614
• Languages: English
• ISSNs: 2352-409X

Abstract

Highlights: The main geological units in Adelaide, South Australia can be discriminated using strontium isotope analysis of animal teeth. The main physiographic regions in Adelaide, South Australia can not be discriminated based on oxygen isotope analysis, but discrimination between other areas in Australia and internationallly may be possible. Our baseline data set provides the opportunity, for the first time, to provenance materials from archaeological sites in the region. Abstract: Strontium and oxygen isotopes provide a useful method for provenancing bioapaties, such as teeth and bone. In order for this approach to be successful, regional baseline bioavailable isotope data are required; however, few databases are currently available in Australia. This study measured stable oxygen and bioavailable strontium isotope ratios from low mobility fauna sampled from the major geological and physiographic provinces in Adelaide, South Australia in order to create a database for this region. Bioavailable strontium isotope ratios ( 87 Sr/ 86 Sr) obtained from the predominantly siliciclastic metasediments of the Neoproterozoic Adelaide Geosyncline have a range of 0.7122 ± 0.0001 to 0.7202 ± 0.0001. Cainozoic samples (dominantly terrestrial fluvial/lacustrine and marine carbonate sediments) from the Adelaide Plains have values in the range of 0.7098 ± 0.0002 to 0.7121 ± 0.0001. Samples from the alluvial fan sediments near the Eden-Burnside Fault at the boundary between these regions have values of 0.7131 ± 0.0001 to 0.7143 ± 0.0001. Stable oxygen isotope results range from − 9.5 to − 4.5‰ δ 18 OC (VPDB) and do not appear to vary systematically based on elevation, temperature, rainfall or humidity. These results demonstrate that strontium isotopes are potentially a useful tool for provenance studies within the Adelaide area. Oxygen is probably a more appropriate tool for discriminating seasonality rather than location within the study region. This research also suggests that rats are better suited for mapping strontium isoscapes than koalas, and that, while (non-systematic) offsets appear to exist between laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICPMS) and thermal ionisation mass spectrometry (TIMS) data, this effect is considerably less than the variation between geological provenances in the region.