Quaternary tectonic activity in the piedmont of Cordillera Frontal (33º -34ºS) Mendoza

PERUCCA, L., ZÁRATE M Y MEHL, A.

Cenozoic Geology of the Central Andes of Argentina

INCE - Salfity, J. y Marquillas M. R.

Lugar: Salta; Año: 2010;

This paper reviews the characteristics and kinematic 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 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 a 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 Fm); a transtensive regime would have dominated in the southern part (Arroyo Papagayos). No evidences of tectonic activity have 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.