New publication: Sedimentary signatures of basal ice formation and their preservation in ice-marginal sediments

Abstract: Reconstruction of subglacial processes from sedimentological evidence is central to our understanding of glaciological conditions beneath former ice masses. At Svínafellsjökull, southeast Iceland, we assess the extent to which two different processes of basal ice formation (regelation and glaciohydraulic supercooling) can be identified from ice-marginal sediments. Our results indicate that the sedimentary characteristics of deposits produced by these two processes can be distinguished from one another and that it may be possible to recognise evidence of these processes in Quaternary sediments and to reconstruct their spatial pervasiveness. Sediments derived from the melting of regelation basal ice have (i) a massive structure; (ii) a sediment matrix (0 to 10Ф) dominated by coarse sand; and (iii) a higher proportion of angular clasts than supercool basal ice and associated sediments. Sediments derived from “supercool” basal ice (i) can be either massive or layered; (ii) tend to have a silt-dominated matrix; and (iii) contain a slightly higher proportion of rounded and well-rounded clasts than regelation basal ice and sediments. Previous studies indicate that the dominance of silt within supercool basal ice may be unique to this process, and hence, supercooling should leave a readily recognisable signature in the sedimentary record. Our results from Svínafellsjökull lend support to that idea, although we suggest that further work is required to assess whether silt dominance is a process signature diagnostic of supercooling, and in particular, the extent to which subglacial sediment supply determines the sedimentary character of basal ice facies and associated sediments.

Cook, S.J., Graham, D.J., Swift, D.A., Midgley, N.G. and Adam, W.G., 2011. Sedimentary signatures of basal ice formation and their preservation in ice-marginal sediments. Geomorphology, 25 (1), pp.122-131.

Publisher link: http://dx.doi.org/10.1016/j.geomorph.2010.08.018 (subscription required)

Preprint: http://hdl.handle.net/2134/7884 (no subscription required)

Sedimetrics is an award winner!

David Graham and Ian Reid (centre) receiving their award from Sir Nigel Rudd, Chancellor of Loughborough University, and Anne Davies, presenter of BBC East Midlands Today.
David Graham and Ian Reid (centre) receiving their award from Sir Nigel Rudd, Chancellor of Loughborough University, and Anne Davies, presenter of BBC East Midlands Today.

David Graham, Steve Rice and Ian Reid have been highly commended in the ‘Consultancy’ category of the Loughborough University Enterprise Awards. They were nominated for the development of software that helps engineers, ecologists and geomorphologists better understand and manage the river environment by providing information about river-bed sediments in a cost-effective way. The software – marketed under the brand name ‘Sedimetrics®’ – was developed in the Department of Geography at Loughborough University

The Enterprise Awards are a celebration of the enterprising culture that is such an integral part of the University. Sir Nigel Rudd, Chancellor of the University and BAA Chairman, presented the awards on 6 October 2010.

Read the press release here: http://www.lboro.ac.uk/service/publicity/news-releases/2010/152_Enterprise_Awards.html

Further information about Sedimentrics® is available at http://sedimetrics.com.