Linkages and Feedbacks in Orogenic Systems

Basement-cover tectonics, structural inheritance, and deformation migration in the outer parts of orogenic belts: A view from the western Alps
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Published:September 11, 2017
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CiteCitation
Robert W.H. Butler, 2017. "Basement-cover tectonics, structural inheritance, and deformation migration in the outer parts of orogenic belts: A view from the western Alps", Linkages and Feedbacks in Orogenic Systems, Richard D. Law, J. Ryan Thigpen, Arthur J. Merschat, Harold H. Stowell
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ABSTRACT
The structure and geology of former rifted continental margins can exert significant influence on their subsequent incorporation into collisional orogens. While thinned continental crust attached to the subducting mantle lithosphere may be incorporated into subduction channels, the weakly rifted parts of the margin are likely to resist subduction and thus deform ahead of the main orogenic front. This expectation is corroborated by a case study from the external western Alps. The former Dauphinois basins have inverted to form external basement massifs. Much of the deformation was widely distributed, with few localized thrust structures. Existing models that invoke distinct deformation events separated in time by a major (late Eocene, “Nummulitic”) unconformity are abandoned here in favor of crustal shortening that was continuous in time. Integrated stratigraphic, paleothermal, and geochronological data reveal that basin inversion was protracted over 6–10 m.y., coeval with deformation in the more internal parts of the chain. The notion of continuous, rather than episodic, deformation raises issues for the ways in which rates and tectonic activity may be evaluated within ancient orogens.
- Alps
- basement
- basin inversion
- carbonate platforms
- Cenozoic
- cross sections
- crust
- crustal shortening
- deformation
- Europe
- France
- French Alps
- lithostratigraphy
- Mesozoic
- models
- orogenic belts
- orogeny
- plate collision
- plate tectonics
- sedimentary cover
- sedimentary rocks
- tectonics
- Tertiary
- thermal history
- turbidite
- Western Alps
- Western Europe
- southeastern France
- Ecrins Massif