Interplay between constructive deep mechanisms building the Central Andes and the stress field

GIAMBIAGI, LAURA; SPAGNOTTO, SILVANA; TASSARA, ANDRÉS; SURIANO, JULIETA; MESCUA, JOSÉ; LOSSADA, ANA; BARRIONUEVO, MATÍAS; JULVE, J

Congreso; Latin-American Colloquium; 2019

Both in continental collision and subduction-related orogens, different kinds of mega-detachments have beenproposed to explain the horizontal shortening, crustal thickening and topographic uplift. In fold-and-thrustbelts, these detachments have traditionally been located inside levels of mechanical anisotropies. Theseorogenic wedges thicken towards the hinterland, reaching depths located in the brittle-ductile transition. Atan orogenic scale, these shear zones are not controlled by frictional sliding, but rather by temperature,composition, strain rate, and the stress field. While the synergies between crustal deformation, exhumationand sedimentation processes are well-known to a first order, it is challenging to evaluate the interplaybetween constructive deep mechanisms and the in-situ stress field. Two outstanding questions in the study oforogenic processes are: How does shallow structures in the foreland fold-and-thrust belt connect with ones inthe hinterland under an evolving and changing stress field? How long can a detachment remain active duringan orogenic event?