New methods to reconstruct clast transport history in different glacial sedimentary environments: Case study for Old Red sandstone clasts from polythermal Hrbyebreen and Bertilbreen valley glaciers, Central Svalbard

Vol.3,No.2(2013)

Abstract

The objective of this study were Little Ice Age (LIA) to recent subglacial tills, glaciofluvial sediments of proglacial sandur, esker sediments and sediments of moraine-mound complexes of Hrbyebreen polythermal valley glacier and LIA to recent sediments of lateral moraine, frontal moraine, ice-cored moraine and glaciofluvial sediments of proglacial sandur of Bertilbreen polythermal valley glacier. Fossil (probably early Holocene) subglacial and supraglacial tills and sediments of coarse-grained glaciomarginal delta of Bertilbreen have also been studied. The research focused on Old Red sandstone clasts, for which roundness, shape and striation presence have been investigated. The results from this research led to the proposal of new methodological approaches. It is mainly the covariant plot of striations and RA (the share of striated clasts versus the share of very angular and angular clasts), which effectively differentiate subglacial tills from glaciofluvial sediments and allows for identification of the source material of moraine-mound complexes, especially the oldest, more degraded parts near the maximum LIA glacier extent. The second is the covariant plot of distance and RS index (the distance from the starting point versus the share of subangular and subrounded clasts) to present downstream roundness trends in proglacial glaciofluvial sediments. The research confirmed the crucial role of lithological properties of thinly bedded rocks on the shape of these rock clasts in sediment and a minimum impact of passive and active transport on the clast shape modification.


Keywords:
clast striation; clast roundness; clast shape; Old Red sandstone clasts; glacial sedimentary environments; Svalbard
References

Adam, W. G., Knight, P. G. (2003): Identification of basal layer debris in ice-marginal moraines, Russell Glacier, West Greenland. Quaternary Science Reviews, 22: 1407-1414.

Benn, D. I., Ballantyne, C. K. (1994): Reconstructing the transport history of glacigenic sediments: a new approach based on the co-variance of clast form indices. Sedimentary Geology, 91: 215-227.

Bennett, M. R., Hambrey, M. J. and Huddart, D. (1997): Modification of clast shape in high-arctic glacial environments. Journal of Sedimentary Research, 67: 550-559.

Bennett, M. R., Hambrey, M. J., Huddart, D., Glasser, N. F. and Crawford, K. (1999): The landform and sediment assemblage produced by a tidewater glacier surge in Kongsfjorden, Svalbard. Quaternary Science Reviews, 18: 1213-1246.

Boothroyd, J. C., Ashley, G. M. (1975): Processes, bar morphology, and sedimentary structures on braided outwash fans, northeastern Gulf of Alaska. In: A. V. Jopling, B. C. McDonald (eds.): Glaciofluvial and Glaciolacustrine Sedimentation. SEPM Special Publication, 23: 193-222.

Boulton, G. S. (1978): Boulder shapes and grain-size distributions of debris as indicators of transport paths through a glacier and till genesis. Sedimentology, 25: 773-799.

Bridge, J. S. (2003): Rivers and Floodplains. Form, Processes and Sedimentary Record. Blackwell Publishing, Oxford, UK, 2003, 491 p.

Dallmann, W. K., Piepjohn, K. and Blomeier, D. (2004): Geological map of Billefjorden, Central Spitsbergen, Svalbard with geological excursion guide. Norsk Polarinstitutt.

Evans, D. J. A., Strzelecki, M., Milledge, D. G., and Orton, C. (2012): Hrbyebreen polythermal glacial landsystem, Svalbard. Journal of Maps, 8: 146-156.

Ewertowski, M., Kasprzak, L., Szuman, I., and Tomczyk, A. M. (2011): Controlled, ice-cored moraines: sediments and geomorphology. An example from Ragnarbreen, Svalbard. Zeitschrift für Geomorphologie, 56: 53-74.

Glasser, N. F., Harrison, S. and Jansson, K. N. (2009): Topographic controls on glacier sediment-landform associations around the temperate North Patagonian Icefield. Quaternary Science Reviews, 28: 2817-2832.

Gustavson, T. C. (1974): Sedimentation on gravel outwash fans, Malaspina Glacier Foreland, Alaska. Journal of Sedimentary Petrology, 44: 374-389.

Hambrey, M. J. (1994): Glacial environments. UCL Press, London, UK, 1994, 296 p.

Hambrey, M. J., Bennett, M. R., Dowdeswell, J. A., Glasser, N. F. and Huddart, D. (1999): Debris entrainment and transfer in polythermal valley glaciers. Journal of Glaciology, 45: 69-86.

Hambrey, M. J., Ehrmann, W. (2004): Modification of sediment characteristics during glacial transport in high-alpine catchments: Mount Cook area, New Zealand. Boreas, 33: 300-318.

Hambrey, M. J., Glasser, N. F. (2012): Discriminating glacier thermal and dynamic regimes in the sedimentary record. Sedimentary Geology, 251-252: 1-33. XXXXXXXXXXXXXXXXXX

Hambrey, M. J., Huddart, D., Bennett, M. R. and Glasser, N. F. (1997): Genesis of ‘hummocky moraines’ by thrusting in glacier ice: evidence from Svalbard and Britain. Journal of the Geological Society, London, 154: 623-632.

Hanáček, M., Flašar, J. and Nývlt, D. (2011): Sedimentary petrological characteristics of lateral and frontal moraine and proglacial glaciofluvial sediments of Bertilbreen, Central Svalbard. Czech Polar Reports, 1: 11-33.

Hein, F. J., Walker, R. G. (1977): Bar evolution and development of stratification in the gravelly, braided, Kicking Horse River, British Columbia. Canadian Journal of Earth Sciences, 14: 562-570.

Huddart, D. (1994): Rock-type controls on downstream changes in clast parameters in sandur systems in southeast Iceland. Journal of Sedimentary Research, 64: 215-225.

Huddart, D., Bennett, M. R. and Glasser, N. F. (1999): Morphology and sedimentology of a high-arctic esker system: Vegbreen, Svalbard. Boreas, 28: 253-273.

Kjr, K. H. (1999): Mode of subglacial transport deduced from till properties, Mýrdalsjökull, Iceland. Sedimentary Geology, 128: 271-292.

Moncrieff, A. C. M. (1989): Classification of poorly-sorted sedimentary rocks. Sedimentary Geology, 65: 191-194.

Nývlt, D., Hoare, P. G. (2011): Petrology, provenance and shape of clasts in the glaciofluvial sediments of the Mníšek member, northern Bohemia, Czechia. Journal of Geological Sciences, Anthropozoic, 27: 5-22.

Powers, M. C. (1953): A new roundness scale for sedimentary particles. Journal of Sedimentary Petrology, 23: 117-119.

Rachlewicz, G., Szczuciński, W. and Ewertowski, M. (2007): Post- „Little Ice Age“ retreat rates of glaciers around Billefjorden in central Spitsbergen, Svalbard. Polish Polar Research, 28: 159-186.

Smith, N. D. (1974): Sedimentology and bar formation in the Upper Kicking Horse River, a braided outwash stream. Journal of Geology, 82: 205-223.

Sneed, E. D., Folk, R. L. (1958): Pebbles in the lower Colorado River, Texas, a study in clast morphogenesis. Journal of Geology, 66: 114-150.

,

Metrics

0


187

Views

25

PDF views