Delineating the Devonian-Mississippian boundary based on Palynology at Zudañez in Bolivia

DI PASQUO, M.; IANNUZZI, R.; RICE, B.J.,; GRADER, G.; DIAZ-MARTINEZ, E.; ISAACSON, P.; ANDERSON, H.; SHIRLEY LOPEZ

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Congreso; II Simposio Internacional de Paleontología de Perú,; 2018

INGEMMET y Sociedad Paleontológica de Perú

The aim of this contribution is to present the first palynological assemblage recovered from deposits cropping out in the Zudañez area, as part of a major project of Devonian-Permian studies in Bolivia (Fig. 1). The lower stratigraphic deposits in this region characterized by a syncline ? anticline complex, correspond to the Devonian Iquiri Formation, represented by heterolithic deposits with micaceous remains and bioturbation. Over an angular unconformity, an incognitous age-succession starts with alternated gray fangolites and diamictites embedding deformed sand bodies and probable Devonian olistoliths, followed by whitish sandstone beds with pebbly clasts and current structures and red diamictite. Over a parautochtonous contact, another section exhibits whitish sandstone and gray silt/mud and coal levels with plant fossils and interbedded green, gray and red shale/siltstone beds and whitish and red sandstones with current structures, rip-ups, bioturbation and tilloids. The palynological analysis of this succession allowed us to date and establish the stratigraphic units and to propose a correlation to palynofloral zones from South America and elsewhere