Cenozoic deformation and tectonic style of the Andes, between 33° and 34° South Latitude.

GIAMBIAGI, L., RAMOS, V., GODOY, E. ALVAREZ, P. Y ORTS, S.

TECTONICS

American Geophysical Union

Año: 2003 p. 1041 - 1056

0278-7407

The Andes of Argentina and Chile at the latitudes between 33° and 34° S are composed by Oligocene to Miocene volcanic arcs and the Neogene east-vergent Aconcagua fold and thrust belt of the Cordillera Principal, and the basement-block faulted Cordillera Frontal. A regional cross section suggests that shortening across the Andes was achieved by thrusting along detachments at several levels in the crust. While thin-skinned deformation along newly formed thrusts occurred in Mesozoic sequences of the eastern Cordillera Principal, reactivation of pre-existing Jurassic and Oligocene normal faults has resulted in additional hybrid thick- and thin-skinned structures in the western Cordillera Principal. Five major thrusting events are recognized in this part of the Andes: (1) Early to Middle Miocene tectonic inversion of the extensional faults in the western Cordillera Principal, (2) Middle to Late Miocene development of the Aconcagua fold and thrust belt, (3) Late Miocene uplift of Cordillera Frontal, (4) Late Miocene – Early Pliocene out-of-sequence thrusting in the Cordillera Principal, and (5) Pliocene to present deformation of the foreland.