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New geomorphological and chronological constraints for glacial deposits in the Rivoli‐Avigliana end‐moraine system and the lower Susa Valley (Western Alps, NW Italy)
Author(s) -
IvyOchs Susan,
Lucchesi Stefania,
Baggio Paolo,
Fioraso Gianfranco,
Gianotti Franco,
Monegato Giovanni,
Graf Angela A.,
Akçar Naki,
Christl Marcus,
Carraro Francesco,
Forno Maria Gabriella,
Schlüchter Christian
Publication year - 2018
Publication title -
journal of quaternary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.142
H-Index - 94
eISSN - 1099-1417
pISSN - 0267-8179
DOI - 10.1002/jqs.3034
Subject(s) - moraine , geology , last glacial maximum , glacier , foreland basin , surface exposure dating , terminal moraine , geomorphology , glacial period , alluvial fan , glacier terminus , physical geography , paleontology , ice stream , climatology , geography , cryosphere , sea ice , structural basin
Our new dataset from the Rivoli‐Avigliana end‐moraine system, the westernmost amphitheatre of the Italian Alps, provides an important step towards understanding foreland‐reaching glaciations before and during the Last Glacial Maximum (LGM) in the Western Alps. 10 Be data from six boulders in pre‐LGM deposits gave ages between 26.8 ± 2.1 and 41.2 ± 1.9 ka. Based on morphological and pedological data, we interpret the oldest age as a minimum age for the glacier advance(s). 10 Be results suggest that the LGM occurred in two major steps. During the first at 24.0 ± 1.5 ka, several ridges were constructed demonstrating oscillation of the Dora Riparia glacier snout at the maximum position. Our data demonstrate a significantly larger LGM extent in the Rivoli‐Avigliana amphitheatre than shown on previous maps. The maximum advance was followed by a short re‐advance of the glacier at 19.6 ± 0.9 ka, as recorded by 10 Be ages from boulders in lateral positions along the lower Susa Valley. The maximum ice surface during the LGM was at 1000–920 m a.s.l. in the final reach of the valley (560–620 m of elevation above the alluvial plain) and at 620–340 m a.s.l. at the continuous moraines in the amphitheatre.