Les Roches Basiques Du Bas-Limousin (Massif Central Français) : Geochimie Et Implications Geodynamiques

Abstract

The upper unit gneisses represent most of the Bas - Limousin. It is characterized by the intercalation of basic igneous rocks (metagabbro- and metadolerite). These are affected by regional metamorphism but primary textures are preserved. The aim of this work is to present new geochemical data, which allow characterizing the geochemical nature of these rocks and discussing their geodynamic meaning. Chemical analyzes of the major and traces elements were carried out at “Service commun des sciences de la terre de l’ Université de Nancy I”, rare earths elements were analyzed at CRPG of Nancy. The results of this geochemical study show that these basic rocks are comparable to continental tholeiitic rocks.