Glacio-tectonics and the evolution of push moraines
The spatial analysis of glacial landforms is an essential tool in reconstructing ancient ice sheets. These landforms are the clues in the landscape from which the dimensions, geometry, dynamics and history of former ice sheets can be reconstructed. Essential in this work is modern analogue data on key glacial landforms. Data on the sedimentary architecture, morphology of these key landforms is required linked critically to the glaciological and environmental controls which limit their formation. Find that landform in the landscape you then have key data about the glacier which formed it and the environmental conditions that pertained during its formation.
One important landform in this context are push moraines which form along an advancing ice margins. Push moraines contain valuable information about the interaction of a glacier with the foreland into which it advances. The distribution of push moraines is restricted at modern glaciers; they do not occur at every ice margin and are, therefore, associated with either specific glaciological scenarios, the occurrence of conditions favourable for deformation in the glacial foreland, or more likely some combination of both. As a consequence push moraines have considerable potential in palaeo-glaciological investigations as well as being an important part of the glacial system in their own right. They also have a much wider geological context than many glacial landforms since they provide potential analogues for the thin-skin tectonics within orogenic belts.
To date our understanding of push moraine formation has been limited by the lack of real-time process-based observations and the lack of sedimentary exposure through push moraines at modern glacier margins. Increasingly the latter problem can be addressed through the application of modern geophysical techniques such as Ground Penetrating Radar (GPR). At Hagafellsjökull-Eystri in Iceland Professor Bennett has been using GPR to understand the geo-mechanical evolution of a series of push moraines.
Selected Publications
BENNETT, M.R., HAMBREY, M.J., HUDDART, D., GLASSER, N.F. & CRAWFORD, K. 1999. The landform and sediment assemblage produced by a tidewater glacier surge in Kongsfjorden, Svalbard. Quaternary Science Reviews 18, 1213-1246.
BENNETT, M.R., HUDDART, D. & GLASSER, N.F. 1999. Large-scale bedrock displacement by cirque glaciers. Arctic, Antarctic, and Alpine Research 31, 99-107.
BENNETT, M.R. 2001. The morphology, structural evolution and significance of push moraines. Earth Science Reviews 53, 197-236.
BENNETT, M.R., HUDDART, D., WALLER, R.I. CASSIDY, N., TOMIO, A., ZUKOWSKYJ, P., MIDGELEY, N.G., COOK, S.J., GONZALEZ, S., GLASSER, N.F. 2004. Sedimentary and tectonic architecture of a large push moraine: a case study from Hagafellsjokull-Eystri, Iceland. Sedimentary Geology 172, 269-292.
BENNETT, M.R., WALLER, R.I, MIDGLEY, N.G., HUDDART, D., GONZALEZ, S., COOK, S.J. & TOMIO, A. 2004. Styles of ice-marginal deformation at Hagafellsjokull-Eystri during the 1998/99 winter-spring surge. Boreas, 33, 97-101.
BENNETT, M.R., HUDDART, D., WALLER, R.I. 2005. The interaction of a surging glacier with a seasonally frozen foreland: Hagafellsjokull-Eystri, Iceland. In: Harris, C. & Murton, J.B. (eds) Cryospheric Systems. Geological Society Special Publication 2452, 51-62.
For more details contact Professor Matthew Bennett
