Marion Island volcanism and glaciation

• Published in: Antarctic Science
• Main Authors: Hall, Kevin John, Meiklejohn, K.I. (Ian), Bumby, Adam John
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2011
• Subjects: Glacier reconstruction; Glacier-volcanic interactions; Peri-Antarctic islands; Faults (Geology) > Prince Edward Islands > Marion Island; Glaciology > Prince Edward Islands > Marion Island; Paleoclimatology > Prince Edward Islands > Marion Island; Volcanism > Prince Edward Islands > Marion Island; Antarctic; Antarc*; Ice cap; Marion Island; Prince Edward Islands
• Online Access: http://hdl.handle.net/2263/18935; https://doi.org/10.1017/S0954102010000878

Sub-Antarctic Marion Island was the site of extensive volcanism as well as glaciation during both the Quaternary and the Holocene. Initial reconstructions suggested a link between deglaciation and the initiation of faulting which, in turn, facilitated lava eruptions during the interglacials. However, our reassessment of the faulting, volcanic rock, and palaeoglacier distribution indicate that these original interpretations were erroneous. Features thought to be due to faulting are shown to be erosional scarps and this significantly changes interpretations of former glacier distribution. Further, the loss of the former ice cap has revealed new information on former glaciers and their flow directions, thereby allowing reconstruction of palaeoglaciers. Our new reconstruction fits with information from invertebrate genetic mapping that suggest some lava outcrops were nunataks and, therefore, refuges during the Last Glacial period. The new findings of glacial landforms in areas previously covered by snow suggest there was a significant ice advance during the Little Ice Age. Although Holocene volcanic rocks overlie and mask much of the glacial evidence, it has been possible to develop a proposed new reconstruction for glaciation, which is presented together with some of the implications. The University of Northern British Columbia helped KH with some of the travel costs associated with undertaking this work. Funding for the project was provided by the National Research Foundation Grants SNA2005061300001 (IM) and SNA2008050800005 (AB). http://journals.cambridge.org/action/displayJournal?jid=ans nf2012