Condiciones P-T en xenolitos mantélicos de los volcanes la Banya del Boc y el Puig d’Adri (Girona)

Abstract

Several thermometers and one barometer are used in order to determine the P-T conditions of type I xenoliths enclosed in alkaline mafic lavas from the Catalan Neogene-Quaternary volcanism. Average temperatures from the different thermometers are similar and higher in harzburgites (1106- 1036º C) than in lherzolites (1043- 867º C), and one pyroxenite shows similar T to harzburgites (1078º C). Low standard deviation for the T estimates reflects equilibrium in most samples for the thermometric reactions. Pressure estimates show high uncertainty, except for few samples, the pyroxenite included, which give consistent values (15.0- 9.6 kbar) within the spinel lherzolite field