Quantifying the response of Australian landscapes to climatic and tectonic forcing using cosmogenic isotope analysis

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dc.contributor.authorFink, Den_AU
dc.contributor.authorQuigley, Men_AU
dc.contributor.authorKohn, BPen_AU
dc.date.accessioned2011-10-19T04:34:52Zen_AU
dc.date.available2011-10-19T04:34:52Zen_AU
dc.date.issued2011-07-21en_AU
dc.date.statistics2011-10-19en_AU
dc.description.abstractCosmogenic 10Be concentrations in earth surface materials offer novel information on the rate and spatial patterns of bedrock erosion and basin-wide sediment generation which together influence continental denudation. This opens an opportunity to address the vexing question of how continental landscapes respond to climate and tectonic forcing. One hypothesis is that for equivalent long-term climatic variables, variations in tectonic activity will be reflected in bedrock and sediment 10Be concentrations such that more tectonically active landscapes will yield mean lower 10Be concentrations. We test this hypothesis across the Australian continent by sampling non-glaciated bedrock outcrops and stream sediments from 4 selected ‘end-member’ regions of contrasting climatic (large precipitation, temperature gradients) and tectonic (fault deformation, paleo-earthquake activity) variables with similar granitic lithologies. Localities included tropical northern Queensland and west coast Tasmania (>3000 mm/y), contrasting with late Quaternary neo-tectonically modified regions of the Flinders Ranges, South Australia (<200 mm/y), and tectonically passive but arid Port Hedland and the Darling Scarp, WA. Preliminary cosmogenic-derived erosion rates in regions proximal to active faults with surface ruptures in the last 100 kyr are 1-2 orders of magnitude higher than erosion rates in tectonically inactive regions, implying co-seismic rock fracturing and mass movement exert first order control on bedrock erosion rates on the 100 kyr timescale. Erosion rates derived from subhorizontal bedrock surfaces (and associated stream sediments) spanning Australia's most diverse climates with respect to annual precipitation and temperature gradients are typically <5 m/Ma, implying minimal climatic control on weathering of non-soil mantled bedrock. Cosmogenic nuclide data from across the continent provide quantitative evidence for strong tectonic and weak climatic influence on bedrock erosion. Copyright (c) 2011 INQUA 18en_AU
dc.identifier.citationFink, D., Quigley, M., Kohn, B. (2011). Quantifying the response of Australian landscapes to climatic and tectonic forcing using cosmogenic isotope analysis. Presentation to the 18th International Union for Quaternary Research Congress, 21th-27th July 2011, Berne Switzerland.en_AU
dc.identifier.conferenceenddate27 July 2011en_AU
dc.identifier.conferencename18th International Union for Quaternary Research Congressen_AU
dc.identifier.conferenceplaceBerne Switzerlanden_AU
dc.identifier.conferencestartdate21 July 2011en_AU
dc.identifier.govdoc3230en_AU
dc.identifier.urihttp://www.inqua2011.ch/?a=programme&subnavi=abstract&id=1293en_AU
dc.identifier.urihttp://apo.ansto.gov.au/dspace/handle/10238/3835en_AU
dc.language.isoenen_AU
dc.publisher18th INQUA Congressen_AU
dc.subjectIsotope ratioen_AU
dc.subjectTectonicsen_AU
dc.subjectBeryllium 10en_AU
dc.subjectSedimentsen_AU
dc.subjectClimatesen_AU
dc.subjectErosionen_AU
dc.titleQuantifying the response of Australian landscapes to climatic and tectonic forcing using cosmogenic isotope analysisen_AU
dc.typeConference Presentationen_AU
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