Producción CyT
Congreso
Autoría
Fecha
2017
Editorial y Lugar de Edición
Asociación Geológica Argentina
Resumen
Información suministrada por el agente en
SIGEVA
The Auca Mahuida volcanic shield is located on the southernmost part of the Payenia Volcanic Province on the retroarc of the Southern Central Andes. After a ~15 My period of shallow subduction in the area (Kay 2006, Ramos y Folguera 2009), a sudden steepening of the Nazca plate during the last 4 Ma triggered a strong tearing located below the Auca Mahuida Plateau, evidenced by seismic tomographies (Pesicek et al. 2012). Evenmore, resistivity studies from Burd et al. (2015) described a complex p...
The Auca Mahuida volcanic shield is located on the southernmost part of the Payenia Volcanic Province on the retroarc of the Southern Central Andes. After a ~15 My period of shallow subduction in the area (Kay 2006, Ramos y Folguera 2009), a sudden steepening of the Nazca plate during the last 4 Ma triggered a strong tearing located below the Auca Mahuida Plateau, evidenced by seismic tomographies (Pesicek et al. 2012). Evenmore, resistivity studies from Burd et al. (2015) described a complex plume head impacting at the southern Payenia plateau, feeding individual volcanic centers. The present work provides new-high resolution gravity and aerial-magnetic data that constitute undocumented information for the interpretation of the structure of the continental crust, subducted slab and upper mantle below the Auca Mahuida Plateau. A correlation between shallower resistivity isosurfaces (33?52 km depth) associated with the plume and the measured magnetic data, depicts a ~150 km in diameter circular anomaly. Using the EIGEN-6c4 model, Geoid data have been filtered in order to isolate deeper mass influences. This allows identifying a good correlation between the anomalous masses in the upper crust, a positive undulation due to anomalous masses in the upper mantle and possibly the tearing of the ocean slab. This work provides new data on the spatial relation between an asthenospheric anomaly, the tearing produced on the Nazca plate and a laccolith intruding the upper crust.
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Palabras Clave
magnetic dataGeoidPlumeRetroarc volcanism