Browsing by Author "Reid, C"
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- ItemLate Holocene environmental change of Te Whakaraupō | Lyttelton Harbour, New Zealand(Australasian Quaternary Association Inc., 2022-12-06) Hanson, J; Reid, C; Prebble, M; Shulmeister, J; Moy, CM; Zawadzki, A; Hua, QDue to the increasing impacts of climate change, global sea levels and ocean temperatures have been rapidly increasing. One region which will be affected by these increased sea levels are the bays of Horomaka | Banks Peninsula on the east coast of the South Island, New Zealand. Horomaka is a poorly understood landscape that has been highly modified by human land management in both Māori and European times. This research will investigate the interactions between changes in the coastal system and the surrounding catchments which are deeply incised valleys in the flanks of an old volcanic complex. The work focusses on three locations: Te Whakaraupō | Lyttelton Harbour, Kawatea | Okains Bay and Te Wairewa | Lake Forsyth and uses a combination of micro-fossil, geochemical and sedimentological proxies to decipher ecological, hydrological and anthropomorphic changes in these catchments. Here we present our preliminary findings from Te Whakaraupō | Lyttelton Harbour, where a 3.4 m shallow marine sediment core was collected from the mudflats of the innermost harbour. Foraminiferal records indicate a rapid infilling of the harbour with a shift in conditions from low intertidal to high intertidal to present day salt marsh. This change in sedimentation is reflected in our X-ray Fluorescence results, which show increased variability in terrigenous sediment and organic content at the top of the record. This research presents the first of its kind in Horomaka to reconstruct past environmental conditions over time. Future research will include pollen and micro-charcoal analyses and grain size analysis to amplify the palaeoenvironmental data. This research will develop key information on changes in both marine and terrestrial environmental change and sedimentation rates over the late Holocene, which will help inform the management response to enhanced climate change and urban development in the harbour.
- ItemMan and megafauna in Tasmania: closing the gap(Elsevier B.V., 2012-03-22) Gillespie, R; Camens, AB; Worthy, TH; Rawlence, NJ; Reid, C; Bertuch, F; Levchenko, VA; Cooper, ARecent discussion on the late Pleistocene extinction of the Australian megafauna has revolved around interpretation of several key fossil sites in Tasmania. It has been suggested that humans did not arrive in Tasmania until after the megafauna became extinct, or did not hunt now extinct megafauna, and therefore that humans cannot be implicated in the extinctions. Radiocarbon results from these sites indicate that the youngest extinct megafauna are close to charcoal ages from the oldest archaeological deposits, although difficulties have arisen in establishing chronologies because most relevant sites have ages near the limit for radiocarbon analysis. We report a series of new radiocarbon ages, delta C-13, delta N-15 and C:N ratios on collagen and dentine fractions from skeletal remains in the Mount Cripps karst area and the Mowbray Swamp, both in northwestern Tasmania, and discuss the reliability of ages from these and other sites. We also report the discovery of an articulated Simosthenurus occidentalis skeleton at Mt Cripps, that represents only the second directly-dated extinct megafaunal taxon with a reliable age <50 ka cal BP from Tasmania. Our results suggest that C:N ratios measured on collagen or dentine are not an infallible guide to radiocarbon age reliability. We confirm previous reports of a temporal overlap between the megafaunal and archaeological records in Tasmania, but the presence of archaeological evidence and megafauna with the same age at the same site has not yet been demonstrated. At least two megafaunal taxa-the now-extinct Protemnodon anak and a giant Pleistocene form of the extant Macropus giganteus-were still present in Tasmania after 43 ka, when human crossing of the Bassian landbridge from mainland Australia first became sustainable. © 2012, Elsevier Ltd.