Characterisation of magnetic minerals from southern Victoria
Details of Research
TitleCharacterisation of magnetic minerals from southern Victoria Land, AntarcticaAbstractMagnetic properties of sedimentary strata recovered in Antarctic drill-cores from southern McMurdo Sound have been used to deduce climatic processes, but interpretation is limited by lack of information regarding the magnetic mineralogy of potential source rocks. Here we assess the magnetic mineralogy, concentration and grain size of magnetic remanence carriers in exposed rocks of southern Victoria Land and evaluate their potential contribution to Holocene-modern sediments. Modern sediments contain high concentrations of Ti-magnetite likely derived from the McMurdo Volcanic Group and minor concentrations of high-coercivity minerals, possibly derived from the Skelton Group and Beacon Supergroup. Significant quantities of superparamagnetic grains are present in all cover sediments, which were probably generated through glacial (grinding) processes or during sediment transport. We suggest that modern, hyper-arid conditions in southern Victoria Land prevent alteration of superparamagnetic grains and that they may be a useful proxy for the modern climate state. Copyright 2015 The Royal Society of New Zealand.AcknowledgementsWe thank Andrew Roberts and an anonymous reviewer for their constructive and rigorous reviews. We thank Pontus Lurcock for assistance with FORC analyses, and Gavin Dunbar and Cliff Atkins for providing modern sediment samples. Logistical support was provided by Ian Turnbull, the GNS Science Department of Regional Geology, Antarctica New Zealand, staff at Scott Base, and R McPhail (Helicopters New Zealand). This work was supported by the New Zealand Foundation for Research, Science and Technology as part of the New Zealand PACAFI grant (contract C05X1001).
TypeArticleCitationOhneiser, C., Wilson, G. and Cox, S. (2015) Characterisation of magnetic minerals from southern Victoria Land, Antarctica. New Zealand Journal of Geology and Geophysics, 58(1): 52-65 doi:10.1080/00288306.2014.990044
Antarctica NZ (29th Nov 2018). Characterisation of magnetic minerals from southern Victoria . In Website Antarctica NZ. Retrieved 4th Jul 2020 15:41, from https://adam.antarcticanz.govt.nz/nodes/view/63702