Quaternary tectonic activity in the piedmont of Cordillera Frontal (33°S-34°S) Mendoza

LAURA PERUCCA; MARCELO ZÁRATE; ADRIANA MEHL

Cenozoic geology of the central Andes of Argentina

Instituto del Cenozoico Universidad Nacional de Salta

Lugar: Salta; Año: 2011; p. 315 - 326

This paper reviews the characteristics and kinematics of the faults situated in the Cordillera Frontal piedmont from the NW part of the Tunuyán depression in the north to the arroyo Papagayos in the south. Two east vergent reverse faults occur at Loma Sola del Diablo (northern part of Lomas del Peral) with undifferentiated Miocene-Pliocene deposits overlying tectonically fanglomeradic deposits of Los Mesones Fomation (lower  Pleistocene). Three N-S and west-facing scarps have been identified at Lomas del Jaboncillo, with the most developed (Chupasangral) situated to the east. To the south, in the vicinity of Cerro Chalet, an aligned group of small granitic hills with N-S trend has been uplifted by the Chalet fault; southward, the NW-SE Papagayos fault zone is located on the northern margin of arroyo Papagayos. A compressive tectonic activity has predominated in the northern part of the Tunuyán depression from the Miocene to the middle Pleistocene (Las Tunas Formation); a transtensive regime would have dominated in the  southern part (Arroyo Papagayos). No evidence of tectonic activity has been observed in the late Pleistocene-Holocene record. As a working hypothesis, it is considered that the Tunuyán depression, regarded as a foreland basin, has been affected by passive transport and resembles a piggyback basin.