Crustal structure in the southern Andes, adjacent foreland, and Atlantic passive margin delineated by satellite gravimetric models

Abstract Combined models from satellite gravity measurements and terrestrial observations provide a model of Earth’s gravity field with high spatial resolution and accuracy. In this work, we used the combined EIGEN-6C4 model and satellite-only GOCE data, both corrected for topography, to study the crustal structure of the transition zone between the Southern Central Andes and Patagonian Andes, adjacent foreland zone and Atlantic passive margin. We calculated gravity anomalies and vertical gravity gradients for mapping crustal density heterogeneities with the aim of validating and discussing previously proposed crustal models. This work provides additional geophysical constraints for several crustal structures that were discussed and proposed on the basis of geological evidence, such as the Pampean-Pan-African boundary that borders the western edge of the Rio de la Plata craton or the Famatinian paleogeographic boundary that juxtaposes the Laurentia-derived Cuyania and Pampean basement blocks. However, other gravimetric contrasts need to be further evaluated in relation to their tectonic significance, including the Malvinas Fault Zone through the Atlantic passive margin and the internal structure of the North Patagonian Massif. In this work, we highlight that new gravity field models are useful for identifying and mapping with high-precision crustal-order features, providing an innovative tool in geophysical exploration and development of tectonic and paleogeographic models.