Crustal focal mechanisms in the NW sierras de cordoba, and connections with mio-pliocene basement thrusting of the easternmost Sierras Pampeanas, south-Central Andes

Structure and seismogenic activity of the broken foreland to the south of the Chilean-Pampean flat subduction zone: The San Rafael Block

“…The suggested structure of the San Rafael Block, contrary to previous proposals, is similar to the Sierras Pampeanas broken foreland interpretations, where east-dipping listric ramps rooted in the Moho were proposed with an opposite vergence in relation to the general east-Andean vergence (Gonzalez Bonorino, 1950;Jordan and Allmendinger, 1986;Ramos et al, 2002;Vicente et al, 2022). In particular, Introcaso et al (1987) modelled the deep structure of the Sierras de Córdoba (part of the southern Sierras Pampeanas broken foreland) using gravity data, showing that these were uplifted by east-dipping structures rooted in the Moho.…”

“…In those cases, the deep structure models were supported by geophysical data. A more recent work carried out in the easternmost Sierras Pampeanas, based on focal mechanisms and structural geology analysis, showed that the major and medium scale structures of that broken foreland are controlled by the complex structural grain of the basement (Vicente et al, 2022). Similarly, the San Rafael Block region presents a complex history that has imprinted a NW-SE structural grain onto the basement (see geological setting for more details).…”