Palynostratigraphy of upper Paleozoic sequences in central‐western Argentina

Abstract

Lower Carboniferous to Permian palynological zones are described from sections in central‐western Argentina. In ascending stratigraphie order these zones are: (1) the Cordylosporites‐Verrucosisporites (CV) Assemblage Biozone (spanning the Malimán and Cortaderas formations); (2) the Raistrickia densa‐Convolutispora muriornata (DM) Assemblage Biozone (which is subdivided into: Sub‐biozone A in the Guandacol and equivalent formations, Sub‐biozone B in the Tupe Formation and equivalents, and Sub‐biozone C in the upper part of the Santa Máxima and El Imperial formations); (3) the Fusacolpites fusus‐Vittatina subsaccata (FS) Interval Biozone in the Bajo de Véliz and Tasa Cuna formations and equivalents, and (4) the Lueckisporites‐Weylandites (LW) Assemblage Biozone in the De La Cuesta and Yacimiento Los Reyunos formations. The oldest biozone (CV) is assigned to the Early Carboniferous and the overlying DMB iozone to the Late Carboniferous. The uppermost FS and LW biozones are Permian in age. Palynological records show the impact of the Early‐to‐Late Carboniferous glacial event, which caused significant changes in the composition of the assemblages from this interval. Further studies are necessary to calibrate a regional geological time scale in Gondwana, which is essential for precise correlation.