Heterogeneities in the basement of the Iglesia Basin as evidenced by geophysical data.

Abstract

The basement of the Iglesia basin, located in the south of the central Andes, records different tectonic and magmatic processes associated with a long geological evolution spanning from the Paleozoic to the Neogene. Unraveling the structure, presence, and geometry of magmatic bodies in the basement is essential to understand its complex geological evolution. However, its direct study is limited due to a thick cover (~3 km) deposited during the Neogene and the lack of well-data providing information of the lithology at depth. In this work, we performed an analysis of the magnetic signal correlated with seismic data. Magnetic data were processed using filters, enhancement methods, and Euler deconvolution. Finally, an inversion model of the magnetic heterogeneities adjusted with seismic data was built. This model revealed unknown igneous bodies intruding the basement. Here we suggest that these heterogeneities would be related to intrusive bodies, part of the Colangüil Batholith located west of the study area.