IDEAN   23403
INSTITUTO DE ESTUDIOS ANDINOS "DON PABLO GROEBER"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Evolution of Middle to Late Miocene Arc-Related Magmatism Between 35° and 38°S, Southern Central Andes, Argentina
Autor/es:
LITVAK, VANESA D.; SPAGNUOLO, MAURO G.; FOLGUERA, ANDRES; RAMOS, VICTOR A.
Lugar:
Foz de Iguazú, Brasil
Reunión:
Congreso; The Meeting of the Americas; 2010
Institución organizadora:
American Geophysical Union
Resumen:
Middle to Late Miocene mesosilicic volcanism is broadly distributed in a series of volcanic complexes located in a back arc position along a NE trend in southern Central Andes (35°-38° S) whose how chemical signature reflects a variable slab geometry. Volcanic units can be grouped in two stages: the first includes lavas form 10 to 14 Ma of basaltic andesitic to dacitic composition with relatively weak arc signatures while the second stage includes lavas from 8 to 3.5 Ma, which shows an increase of typical arc-related chemical signature. Within this framework, Charilehue volcanics can be related to the first stage mentioned before showing an arc-related chemical signature weaker when compared to younger volcanism. On the contrary, San Rafael volcanism shows strong evidence of slab derived components and arc influence The contrasting spatial distribution, age and chemical signature of Charilehue and San Rafael block volcanism allow understanding the beginning of the slab influence, the real dimensions of arc-expansion, and the evolution of the shallow subduction in southern Central Andes at 35°-38°S.