Neogene exhumation history of the Mont Blanc massif, Western Alps
MetadataShow full item record
The contribution of climate and tectonics to the Neogene exhumation history of the European Alps is studied in the Mont Blanc (MB) massif using low-temperature thermochronology. Apatite fission track and (U-Th-[Sm])/He data suggest that the MB massif was exhumed episodically: Rapid exhumation (2.5 ± 0.5 km/Ma) before 6 Ma is followed by an episode of slow exhumation and a period of accelerated exhumation (>1 km/Ma) after ~3 Ma. Comparing the exhumation rates of the MB massif with reported exhumation rates of all other external crystalline massifs (ECM) shows that the MB massif is the only ECM that experienced rapid exhumation before 6 Ma, which is possibly related to NW and minor SE directed thrusting of the MB massif. The data demonstrate that the Messinian base level drop (~5.5 Ma) and the increase in atmospheric moisture caused by an intensification of the Atlantic Golf Stream (4.6 Ma) did not affect the exhumation of the external Alps. All ECM, except the Gotthard massif, show an increase in exhumation rates at ~3 Ma. We interpret this as the result of normal faulting along orogen-parallel faults and beginning Alpine glaciation. The relative impact of these processes on the exhumation of the ECM can vary spatially and temporally, mainly depending on differences in geology and geomorphology. In the case of the MB massif we propose that the acceleration in exhumation rates at ~3 Ma is caused by rapid valley incision related to glaciation, and that the recent relief of the MB massif is thus a young feature.
Showing items related by title, author, creator and subject.
The age of HP metamorphism in the Gran Paradiso Massif, Western Alps: A petrological and geochronological study of "silvery micaschists"Gabudianu, I.; Rubatto, D.; Gregory, Courtney; Compagnoni, R. (2009)We present a petrological and geochronological study of “silvery micaschists” that crop out in the northern side of the Gran Paradiso Massif, Western Alps, with the aim of constraining P–T conditions and age of the Alpine ...
Tectonic control on the late stage exhumation of the Aar Massif (Switzerland): Constraints from apatite fission track and (U-Th)/He dataReinecker, J.; Danišík, Martin; Schmid, C.; Glotzbach, C.; Rahn, M.; Frisch, W.; Spiegel, C. (2008)We examine the hypothesis that Pliocene exhumation of the external massifs in the central Alps is controlled by climatic change. New thermochronological data from the western Gastern-Aar massif are used to investigate the ...
Constraining long-term denudation and faulting history in intraplate regions by multisystem thermochronology: An example of the Sudetic Marginal Fault (Bohemian Massif, central Europe)Danisik, Martin; Stepancikova, P.; Evans, Noreen (2012)The Rychlebské hory Mountain region in the Sudetes (NE Bohemian Massif) provides a natural laboratory for studies of postorogenic landscape evolution. This work reveals both the exhumation history of the region and the ...