Anomalous luminescence of subglacial sediment at Haut glacier d'Arolla, Switzerland - a consequence of resetting at the glacier bed?

Swift, D.A., Sanderson, D. , Nienow, P.W. and Bingham, R.G. (2010) Anomalous luminescence of subglacial sediment at Haut glacier d'Arolla, Switzerland - a consequence of resetting at the glacier bed? Boreas, 40(3), pp. 446-458. (doi: 10.1111/j.1502-3885.2010.00196.x)

Abstract

<p>Luminescence has the potential to elucidate glacial geomorphic processes because primary glacial sediment sources and transport pathways are associated with contrasting degrees of exposure to light. Most notably, sediment entrained from extraglacial sources should be at least partially reset, whereas sediment produced by glacial erosion of subglacial bedrock should retain substantial luminescence commensurate with a geological irradiation history.</p> <p>We set out to test the validity of this assumption at Haut Glacier d’Arolla, Switzerland using sediment sampled extraglacially and from the glacier bed. Contrary to our expectations, the subglacial samples exhibited natural signals that were substantially lower than those of other sample groups, and further (albeit limited) analyses have indicated no obvious differences in sample group luminescence characteristics or behaviour that could account for this observation. For glaciological reasons, we can eliminate both the possibility that the subglacial sediment has been extraglacially-reset or exposed in situ to heat or light. We therefore advocate investigation of possible resetting processes related to subglacial crushing and grinding, and speculate that such processes, if more generally present, may enable the dating of subglacially-deposited tills using luminescence-based techniques.</p>

• Item Type: Articles
• Additional Information: The definitive version is available at www3.interscience.wiley.com
• Keywords: subglacial sediment, sediment transport, sediment tracing, geomechanical resetting, optically stimulated luminescence, thermoluminescence
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Sanderson, Professor David
• Authors: Swift, D.A., Sanderson, D., Nienow, P.W., and Bingham, R.G.
• Subjects: G Geography. Anthropology. Recreation > GE Environmental Sciences
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Boreas
• ISSN: 0300-9483
• ISSN (Online): 1502-3885
• Published Online: 22 December 2010
• Copyright Holders: Copyright © 2010 The Authors, Copyright © 2010 The Boreas Collegium
• First Published: First published in Boreas 2010 40(3):446-458
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher