Structure of late Variscan Millevaches leucogranite massif in the French Massif Central: AMS and gravity modelling results
| Autor: | Guillaume Martelet, Maurice Brunel, Aude Gébelin, Michel Faure, Yan Chen |
|---|---|
| Přispěvatelé: | Laboratoire Dynamique de la Lithosphère (LDL), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Institut des Sciences de la Terre d'Orléans (ISTO), Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2006 |
| Předmět: |
010504 meteorology & atmospheric sciences
Shear zone [SDE.MCG]Environmental Sciences/Global Changes Pluton Granitic pluton Gravity Context (language use) 010502 geochemistry & geophysics Millevaches 01 natural sciences Lineation AMS Petrology 0105 earth and related environmental sciences [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics geography geography.geographical_feature_category Geology Massif Laccolith Leucogranite Sinistral and dextral French Massif Central Seismology |
| Zdroj: | Journal of Structural Geology Journal of Structural Geology, Elsevier, 2006, 28, pp.148-169. ⟨10.1016/j.jsg.2005.05.021⟩ |
| ISSN: | 0191-8141 |
| DOI: | 10.1016/j.jsg.2005.05.021 |
| Popis: | International audience; In the Limousin area, Variscan leucogranitic plutons are spatially associated with normal faults and major strike-slip shear zones that are a continuation of the South Armorican shear zone. Our study focuses on the large N–S-trending Millevaches granitic massif (Massif Central, France), and intends to highlight, through gravity modelling, structural and anisotropy of magnetic susceptibility (AMS), the massif structure at depth and to discuss the mode of emplacement of granites within a strike-slip tectonic context. The mica subfabric suggests that the magnetic foliations display a general NW–SE sub-horizontal pattern on both sides of the N–S Pradines dextral wrench fault zone that deforms the core of the massif on 5 km width. The magnetic lineation trend exhibits a sigmoïdal pattern, N–S in the Pradines fault zone and NW–SE on both sides of it, which are consistent with a dextral wrench component. The horizontal magnetic foliations and lineations are consistent with the thin granite laccolith model. There is no significant imprint of the extensional Variscan belt collapse on the internal fabric of Millevaches granites than the tectonic dextral transcurrent movement prevailing in this area. |
| Databáze: | OpenAIRE |
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