Tectonic evolution of the northern Malargüe Fold and Thrust Belt, Mendoza Province, Argentina

MARTOS FEDERICO; FENNELL LUCAS; BRISSON LUCIA; PALMIERI GUILLERMO; NAIPAUER MAXIMILIANO; FOLGUERA ANDRÉS

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2020

0895-9811

In this work we study the evolution of one particular segment of the Southern Central Andes, the northern sector of the Malargüe Fold and Thrust Belt (34° - 35° LS), where limited access to the western section has delayed its exploration for years. Analyses of the structure, stratigraphy and sedimentology of different sections along the fold and thrust belt added to the recognition and analysis of growth strata geometries within the foreland basin allowed us to perform an evolutionary model. Our results suggest that during the Lower Jurassic a rift-related depocenter developed next to the international border between Argentina and Chile, which was characterized by an important volcanic contribution from the magmatic arc. This depocenter was reactivated by new extensional phases during the Late Jurassic and the Early Cretaceous respectively and was later inverted in the Late Cretaceous when an incipient fold and thrust belt developed. To the east, growth strata within the Late Cretaceous Diamante Formation suggest that the orogenic front reached an eastern location. Furthermore, petrographic and provenance analyses within the Paleogene units and comparison with detrital zircon ages published by other authors suggest that during this period the magmatic arc and the Andes orogen were the main source area of sediments. The final development of the fold and thrust belt during Neogene time generated growth strata within the wedge top section of the foreland basin, the detection of these geometries within the Agua de la Piedra Formation suggests that the last Neogene compressional phase started between 20 and 15 Ma.