TY - GEN AU - Monzier,M AU - Robin,C AU - Hall,M AU - Cotten,J AU - Samaniego,P ED - International symposium on andean geodynamics, 4 TI - Geochemistry and tectonics at the southern termination of the northern volcanic zone (Riobamba volcanoes, Ecuador); preliminary results N1 - bibliogr. p. 518 ER -