Dechirures continentales et plutonisme; Etude petrologique et structurale comparee de l'association ignee de Guevgueli (Macedoine grecque) et des formations plutoniques basiques situees en bordure nord du Massif des Ballons (Vosges, France)

Abstract

Abstract The Guevgueli igneous association and the Ballons massif are intrusive into a rhyolitic volcaniclastic series. They both contain gabbro-dioritic cumulates and abundant magmatic breccias containing melanocratic microgranular and leucocratic granular rocks. Two distinct parageneses, formed under different PH <sub>2</sub> O, one with bytownite, the other with amphibole + or - biotite + or - ferro-titanian oxides, control the magmatic differentiation processes. Structural studies reveal diastrophisms which favoured a water contribution from the sialic country rocks during magmatic crystallization. An emplacement in continental fractures accounts for the distinctive features of these rocks.