par Michot, Jean ;Weis, Dominique ;Demaiffe, Daniel
Référence Annales de la Société géologique de Belgique, 107, page (15-25)
Publication Publié, 1984-06
Article révisé par les pairs
Résumé : Three different geodynamic occurrences of acidic plutonic rocks have been studied from both petrographical and geochemical (trace elements and isotopes) points of view : the plutonic xenoliths of the Ascension Island lavas (Atlantic Ocean), the granites of the Seychelles archipelago (Indian Ocean) and the charnockites associated with the Rogaland Complex (SW Norway). These granites occur in very different geotectonic situations. The examples show how much contamination can be expected in each case compared to the relative production of granitic material from the differentiation of a mantle derived magma. It is clear that the geological conditions which corresponds to the best mixing situations are those related to the development of large orogenic belts.