Tectono-Stratigraphic reconstruction of the Neoproterozoic Tandilia System: An approach from subsidence analysis

Abstract

Several studies on the Neoproterozoic sedimentary cover of the Tandilia System, Argentina, have been carried out in recent decades. The integration of this knowledge and new results have allowed us to carry out an integral analysis including backstripping technique, forward models, sedimentology, and stratigraphy to provide an integral, innovative, and robust subsidence model to classify this Neoproterozoic basin. The water-loaded subsidence values obtained for the analyzed areas indicate extremely-low accommodation space creation rates. On the other hand, the forward models determined that the initial thickness of the crust and the lithosphere would have been around 35 km and 200 km, respectively, upon which a stretching factor of around 1.09 would have acted. Considering the water-loaded subsidence values, together with the stretch duration, the geometry of the subsidence mechanism, the type and characteristics of the stratigraphic succession and discontinuities, it is feasible to propose that the Neoproterozoic sedimentary units of the Tandilia Basin were accumulated in a cratonic basin that would have originated by processes associated with the fragmentation of the Rodinia Supercontinent. During its evolution, the creation of accommodation space would have been mainly controlled by background subsidence. At the same time, the eustatic oscillations, together with uplift episodes related to lithospheric deglaciation unload, would have subordinately controlled the creation of accommodation space.