Tectonic evolution of the North Patagonian Andes, from the exhumed crystalline rocks to the foreland basin

THOMSON, STUART; OLAIZOLA, EZEQUIEL; GARCÍA MORABITO, EZEQUIEL ; VALENCIA, VICTOR; SANTONJA, CAMILA; YAGUPSKY, DANIEL; BALLESTEROS, JOHN; RAMOS, VICTOR ALBERTO; BECHIS, FLORENCIA; SURIANO, JULIETA; ENCINAS, ALFONSO; ORIOLO, SEBASTIÁN

Simposio; International Symposium on Andean Geodynamics; 2019

Our general goal is to analyze the main tectonic and climatic factors that controlled the late Cenozoic geodynamic evolution of the North Patagonian Andes at about 41°S. To achieve this objective, we conducted an integrated and multidisciplinary study by analyzing the structural architecture, age, and evolution of deformation and exhumation within the fold and thrust belt. The North Patagonian fold and thrust belt at these latitudes shows a general thick-skinned structural style, with involved basement blocks comprised of highly exhumed Paleozoic to Cenozoic metamorphic and plutonic rocks. Local thin-skinned tectonics is also present near the thrust front, where it deforms synorogenic deposits represented by the upper section of the Ñirihuau basin infill. Here we present new thermochronologic and structural data from the exhumed basement blocks, as well as U-Pb dating, structural observations, and sedimentary provenance data from the foreland basin.