Rapid age assessment of glacial landforms in the Pyrenees using Schmidt hammer exposure dating (SHED)
International audience Schmidt hammer (SH) sampling of 54 10 Be-dated granite surfaces from the Pyrenees reveals a clear relationship betweenexposure and weathering through time (n=52, R 2 =0.96, P<0.01) and permits the use of the SH as a numerical datingtool. To test this10 Be-SH calibration cur...
Published in: | Quaternary Research |
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Main Authors: | , , , , , , , |
Other Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2018
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Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-02148042 https://doi.org/10.1017/qua.2018.12 |
Summary: | International audience Schmidt hammer (SH) sampling of 54 10 Be-dated granite surfaces from the Pyrenees reveals a clear relationship betweenexposure and weathering through time (n=52, R 2 =0.96, P<0.01) and permits the use of the SH as a numerical datingtool. To test this10 Be-SH calibration curve, 100 surfaces were sampled from five ice-front positions in the Têt catchment,eastern Pyrenees, with results verified against independent 10 Be and 14 C ages. Gaussian modelling differentiates Holocene(9.4±0.6ka), Younger Dryas (12.6±0.9ka), Oldest Dryas (16.1±0.5ka), last glacial maximum (LGM; 24.8±0.9ka)and Würmian maximum ice extent stages (MIE; 40.9±1.1ka). These data confirm comparable glacier lengths during theLGM and MIE (~300m difference), in contrast to evidence from the western Pyrenees (≥15km), reflecting the relativeinfluence of Atlantic and Mediterranean climates. Moreover, Pyrenean glaciers advanced significantly during the LGM,with a local maximum at ~25ka, driven by growth of the Laurentide Ice Sheet, southward advection of the polar front,and a solar radiation minimum in the Northern Hemisphere. This calibration curve is available online (http://shed.earth) toenable wider application of this method throughout the Pyrenees. |
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