Geological Society of London
SUP18187OA.rtf (77.55 kB)

A tectonostratigraphic synthesis of the Sub-Andean basins: implications for the geotectonic segmentation of the Andean Belt

Download (77.55 kB)
posted on 2016-06-21, 11:57 authored by JohnM. Jacques

The tectonic, structural and depositional history of 19 Sub-Andean foreland and eight southern Caribbean basins has been synthesized and is summarized by regional geohistory charts. These charts recapitulate the subsidence regimes recognized and have been used to evaluate correlations between genetically related stratigraphic sequences. Based on spatial and temporal changes in palaeo-depositional setting, the Sub-Andean region can be subdivided longitudinally into several tectonostratigraphic domains. The differential amount of subsidence between two adjacent tectonostratigraphic provinces or sub-provinces relies on the presence of a transverse zone of structural accommodation. The location of these transfer zones correlates with a number of known and several newly identified zones of intracontinental deformation. Combined with changes in the structural geometry of the Andean Fold and Thrust Belt and the relative dominance of basement fault systems along the length of the Andean foreland, it is suggested that the Andean Belt can be separated into five tectonic domains (which are themselves bounded by transverse, structural accommodation zones). Representing the multiphase reactivation of pre-existing basement fault systems, the influence of these broad zones of transcontinental deformation is most apparent during the Triassic–Jurassic period, suggesting that they were intimately associated with accommodating intraplate stresses during the breakup of the Gondwana Supercontinent.