CIG   05423
CENTRO DE INVESTIGACIONES GEOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
New ages on Lower Jurassic volcanism in the Dorsal de Huincul, Neuquén
Autor/es:
SCHIUMA, M; LLAMBIAS, E.J.
Lugar:
Mendoza
Reunión:
Simposio; 3 Simposio Argentino del Jurásico; 2007
Institución organizadora:
CRICYT
Resumen:
New single zircon ages from wells in the A1 Norte de la Dorsal and Anticlinal Campamento areas of the Neuquén basin indicate that 199.0±1.5 Ma andesite and 203.75±0.26 Ma dacite overlie 286.5±2.3 Ma granodiorite and 284.0±1.3 Ma andesite dike. The Lower Jurassic volcanics were deposited on a regional erosion surface affecting the Permian rocks. In the studied area there is no record of Medium to Upper Triassic volcanics as in other areas of the basin. Exotic zircon crystals gave ages of Mesoproterozoic, Middle Cambian, Early Devonian and Early Carboniferous, suggesting a poliphasic basement. Chemical analyses of three selected samples show a calc-alkaline signature, supporting the existence of a volcanic arc at Early Jurassic as it has been proposed for the center of the basin.