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(Article of periodic en Anglais - 2013)

Document title

Relict talus-foot rock glaciers at Øyberget, Upper Ottadalen, Southern Norway : Schmidt hammer exposure ages and palaeoenvironmental implications

published at : The 50th Anniversary of the First International Conference on Permafrost and Beyond

Authors(s) and Affiliation(s)

MATTHEWS J.A. (1) ; NESJE A. (2 3) ; LINGE H. (2) ;
(1) Dept. of Geography, College of Science, Univ., Swansea, ROYAUME-UNI
(2) Dept. of Earth Science, Univ., Bergen, NORVEGE
(3) Uni Research - Uni Climate, Bergen, NORVEGE

Abstract

Three relict talus-foot rock glaciers at Øyberget, upper Ottadalen, were dated using high-precision Schmidt hammer exposure-age dating (SHD). A SHD calibration curve was constructed for the local banded gneiss using 2 control points : 1) fresh bedrock in a road cutting; and 2) glacially scoured bedrock surfaces deglaciated c. 9.7 ka. obtained for the 3 rock glaciers located ~ 1000 m below the present lower limit of mountain permafrost, at a site covered by glacier ice throughout the Late Weichselian. Two interpretations are presented. First, the rock glaciers may be paraglacial features, the SHD ages are therefore a true reflection of rock glacier age. Second, the rock glaciers may have formed during several thousand years of permafrost conditions in the Mid-Weichselian (possibly during the Ålesund Interstadial), then the true age of the rock glaciers is much older than their SHD ages. Although evidence is currently insufficient to distinguish between these 2 interpretations, the paper demonstrates both the potential and limitations of high-precision SHD in the context of rock glaciers

Source

Thematical fascicle

published at : Permafrost and periglacial processes / ISSN 1045-6740 / CODEN PEPPED

Editor : Wiley, Chichester - ROYAUME-UNI (1990)

Millesime : 2013, vol. 24, no 4 [pp. 336-346]

Bibliographic references : 2 p.

Collation : fig., tabl.

Language

Anglais

Digital Object Identifier

Go to electronic document thanks to its DOI : doi:10.1002/ppp.1794

Tous droits réservés © Prodig - Bibliographie Géographique Internationale (BGI), 2014
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