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

GIAMBIAGI, L.; SPAGNOTTO, SILVANA; TASSARA, A.; SURIANO, JULIETA; MESCUA, J.; LOSSADA, A.C.; BARRIONUEVO, M.; JULVE, JOAQUÍN

Hamburgo

Congreso; LAC 2019 : 25th Latin-American Colloquium of Geosciences; 2021

Universität Hamburg

Both in continental collision and subduction-related orogens,different kinds of mega-detachments have been proposed 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. These orogenic wedges thicken towards the hinterland, reaching depthslocated in the brittle-ductile transition. At an orogenicscale, these shear zones are not controlled by frictionalsliding, but rather by temperature, composition, strainrate, and the stress field. While the synergies betweencrustal deformation, exhumation and sedimentationprocesses are well-known to a first order, it is challengingto evaluate the interplay between constructive deepmechanisms and the in-situ stress field. Two outstandingquestions in the study of orogenic processes are: Howdoes shallow structures in the foreland fold-and-thrustbelt connect with ones in the hinterland under an evolvingand changing stress field? How long can a detachment remain active during an orogenic event?