Reconstrucción estructural de una sección de la Precordillera Occidental Argentina (31º08?ls-69º24?lo) a partir de datos aeromagnéticos

JUAN P. ARIZA; MARTIN MOLINA; NILDA MENDOZA; MYRIAM P. MARTINEZ; GRACIELA VUJOVICH; FLORENCIA BOEDO; SOFIA PÉREZ LUJÁN

Geociencias Aplicadas Latinoamericanas

EAGE

Año: 2015 vol. 2 p. 23 - 32

2352-8281

The magnetic anomaly profile performed along the NE-SW (31º08?LS - 69º24?LO) structural sectionat the western edge of the Argentine Precordillera, is presented. By the application of ratiosbetween bands, Landsat 7 ETM+ satellite images were processed as well as aeromagnetic data byfiltering methods (reduction to the pole and calculation of the residual magnetic anomaly) andemphasized magnetic anomaly (analytical signal). Two lithofacies within the Don Polo Formation(lithofacies I at the base and II at the top of the sequence) were recognised. The main structure ofVilla Corral mountain range is defined by a synclinal fold with a dipping axis to the SE and similarsmaller-scale folds associated, which altogether are fragmented by two landslide systems: the Pre-Andean one, oriented NW-SE inclined fault planes to the NE and top-to-the SW motion; the other,Andean, with N-S direction and inclined fault plane to the W with top-to-the E motion. The analyticalsignal profile shows the importance of magnetic contrasts produced by major landslides thatoverlap clastic metasedimentary rocks of different stratigraphic levels intruded by seams of igneousacidic rock layers. Thus, magnetic methods allow adjusting the distribution of underground unitsaccording to the relative displacement of fault blocks.