Relations plutons et discontinuités lithosphériques
Approche pluridisciplinaire de la mise en place de plutons granitiques le long du Sillon Houiller
(Massif Central Français).
Apports des études de terrain et des données gravimétriques, magnétiques et ASM
pour des modélisations 3D.

摘要

The tectonic role and geodynamic significance of major discontinuities in the late to post-orogenic evolutionare questioned in the Variscan belt. The Sillon Houiller Fault (SHF) is a major sub meridian discontinuity which pre-Stephanian kinematics and evolution remain poorly understood. In order to better understand the role of the SHF duringthe late Variscan evolution of the French Massif Central, a multidisciplinary study has been carried out on some of themassifs which are situated along the fault: petrology, geochronology, Anisotropy of Magnetic Susceptibility (AMS),gravity as well as interpretation of aeromagnetic survey. New geophysical, field and AMS data have been integrated into2D and 3D, forward and inverse, geophysical and geological models, which highlight the geometry and the emplacementof syn-tectonic Namurian plutons. These results allow us to draw the following major conclusions. In Namurian time,the SHF may be related to magma emplacement, as for the Montmarault pluton in the north, or not, as for the Glénat,Omps and Boisset massifs in the south. Nevertheless, all the analyzed granitic plutons record a NW-SE stretchingdirection, perpendicular to the general strike of the SHF. From our structural and kinematics analysis, in Namurian time,if the SHF existed, it should behave as a NW-SE dilatant zone.