3D Architecture of Ultra-Distal Magma-Poor Rifted Margins: the Example of the Fossil Err and Platta Ocean Continent Transition Exposed in the Central Alps in SE Switzerland.
Abstract
Despite the fact that many studies have investigated magma-poor rifted margins, there are still numerous questions concerning the 3D architecture of the Ocean-Continent Transitions (OCT) and the tectono- magmatic processes related to lithospheric breakup. Indeed, it has been observed that the top basement morphology of OCT's at magma-poor rifted margins is heavily structured and complex. The aim of this study is to describe the 3D top basement morphology of OCT's and to define the processes and timing of their formation. To do this, we focused on field observations in the Err-Platta nappes (SE Switzerland) which expose over about 300 km² little overprinted remnants of the fossil Jurassic OCT of the Alpine Tethys. First results of the study show spectacularly exposed structures of the OCT, highlighting the important 3D architecture of the hyperextended crustal and exhumed mantle domains. Key structures are a set of fossil detachment systems showing a complex polyphase tectono-magmatic evolution with: 1) strike and dip variations of detachment systems in the hyperextended crust controlled by inherited structures, 2) the 3D architecture of an exhumed mantle core complex, and 3) the sedimentary and magmatic record associated to these structures. The overall observations provide important information on the temporal evolution and spatial organization of the structural and magmatic systems in ultra-distal magma-poor rifted margins. These systems are at the origin of the creation of the ultra-distal parts of rifted margins and are important for the understanding of the processes controlling lithospheric breakup and creation of a new plate boundary. In this context, our field observations can help to better understand the tectono-magmatic processes at not yet drilled ultra-distal magma-poor rifted margins.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.T41E2994E
- Keywords:
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- 8109 Continental tectonics: extensional;
- TECTONOPHYSICSDE: 8120 Dynamics of lithosphere and mantle: general;
- TECTONOPHYSICSDE: 8169 Sedimentary basin processes;
- TECTONOPHYSICSDE: 8178 Tectonics and magmatism;
- TECTONOPHYSICS