Lithospheric-scale 3D configuration of the Southern Central Andes

SCHECK-WENDEROTH, M.; STRECKER, MANFRED; BOOT, JUDITH; RODRIGUEZ PICEZA, CONSTANZA; PREZZI, CLAUDIA BEATRIZ

Berlin

Congreso; 5th International YES Congress 2019 "Rocking Earth's Future"; 2019

International YES Congress

Intrinsic physical properties of the overriding plate govern the formation of zones of crustal strength and weakness and control the localization and the style of deformation. This is especially true in the case of the Nazca plate subduction and formation of the Andes. The Andean orogen led to the formation of a ~7000 km long N-S mountain range developed along the South American margin and it is the only known present-day case of subduction-type orogen. The Nazca oceanic plate subducts beneath the South American continental plate. Previous studies aimed to constrain lithospheric-scale density and structural heterogeneities in the Southern Central Andes, in the Puna and the Chaco-Paraná basin (~20 - 27°S). This study focuses on the southernmost segment of Central Andes (~27° - 40°S), characterized by a strong N-S and E-W variation in the crustal deformation style and intensity. The aim of the project is to investigate the link between the compositional, thermal and rheological heterogeneities in the overriding plate, the geometry of the subducting plate and the deformation style. First, we will characterize the present-day state of the lithosphere, regarding the density variation and configuration of the sediments, crust and mantle by building a 3D-lithospheric model consistent with all available geological and seismic data and the observed gravity field. This is the first step on the way to later also assess the thermal and rheological state of the lithosphere. This project is supported by the International Research Training Group StRATEGy.