TY  - JOUR
A1  - Garcia, Victor H.
A1  - Hongn, Fernando D.
A1  - Yagupsky, Daniel
A1  - Pingel, Heiko
A1  - Kinnaird, Timothy
A1  - Winocur, Diego
A1  - Cristallini, Ernesto
A1  - Robinson, Ruth Aj
A1  - Strecker, Manfred
T1  - Late Quaternary tectonics controlled by fault reactivation. Insights from a local transpressional system in the intermontane Lerma valley, Cordillera Oriental, NW Argentina
JF  - Journal of structural geology
N2  - We analyzed the Lomas de Carabajal area in the intermontane Lerma valley of the Cordillera Oriental to assess the level of neotectonic activity in a densely populated region of northwestern Argentina. In this region, Plio-Pleistocene synorogenic conglomerates are deformed, locally associated with high-angle faults, and NNW-SSE oriented en-echelon folds characterized by wavelengths of < 1 km. The deformed Quaternary units follow the same pattern of deformation as observed in the underlying Neogene deposits; growth-strata geometries are observed near faults. This configuration is compatible with local left-lateral transpressional tectonism driven by ENE-WSW buttressing against the NW-oriented border of a Cretaceous extensional basin (Alemania sub-basin). Optically Stimulated Luminescence analysis of sandy-silty layers interbedded within the folded late Pleistocene conglomeratic sequence helps to determine uplift rates of 0.83-0.87 mm/a during the last 30-40 ka. Nearby the Lomas de Carabajal, a WNW-striking, 3-m-high fault scarp disrupts radiocarbon dated, 10-ka-old loessic deposits providing a Holocene mean uplift rate of 0.30 mm/a. Our data unambiguously show that shallow crustal deformation in the intermontane Lerma valley is ongoing; some of this deformation may be associated with seismicity. Our findings support the notion of temporally and spatially disparate deformation processes in the broken foreland of the northwestern Argentinean Andes.
KW  - Structural geology
KW  - Neotectonics
KW  - OSL and C-14 geochronology
KW  - Syntectonic sedimentation
KW  - Seismogenic sources
Y1  - 2019
U6  - https://doi.org/10.1016/j.jsg.2019.103875
SN  - 0191-8141
VL  - 128
PB  - Elsevier
CY  - Oxford
ER  -