Uplift and denudation history at low-elevation passive margins: Insights from morphostratigraphic analysis in the SE Armorican Massif along the French Atlantic margin.

Betard, Francois (2010) Uplift and denudation history at low-elevation passive margins: Insights from morphostratigraphic analysis in the SE Armorican Massif along the French Atlantic margin. Comptes Rendus Geoscience, 342 (3). pp. 215-222. DOI 10.1016/j.crte.2010.02.004.

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Abstract

Like other low-elevation passive margins, the French Atlantic margin is characterized by a gradual topographic transition from the coast to low-altitude interior plains or plateaus. Here we propose a morphostratigraphic analysis to constrain long-term landscape evolution and denudation rates, through the characterization of palaeotopographies and related palaeoweatherings in an area restricted to the southeast Armorican Massif. Two regional-scale palaeosurfaces are recognized: (i) the Infraliassic palaeosurface, the truncated weathering profiles of which are sealed by Liassic marine deposits; (ii) the Eocene palaeosurface, underlain by thick kaolinite- and iron-rich palaeosaprolites and by siliceous duricrusts (silcretes). Quantitative constraints on large-scale tectonic uplift and long-term denudation are obtained from these morphostratigraphic markers. Mean uplift and denudation rates calculated on post-Eocene times range between 0.5 and 2 m.Ma-1. These low values imply high landscape stability of the inland margin over most of the Cenozoic.

Document Type: Article
Keywords: Palaeolandforms, Palaeosaprolites, Tectonic uplift, Denudation rates, Morphostratigraphy, Passive margins, Armorican Massif, France
Refereed: Yes
Open Access Journal?: No
Publisher: Elsevier
Projects: Enrichment
Date Deposited: 24 Nov 2017 10:16
Last Modified: 24 Nov 2017 10:16
URI: https://oceanrep.geomar.de/id/eprint/40222

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