Albian dinoflagellate cysts from the Kachaike Formation, Austral Basin, Southwest Argentina

Resumen

The palynological assemblages of the Kachaike Formation at the Bajo Comisión section, Austral
Basin, Argentina, are mainly composed by pteridophyte and bryophyte spores, gymnosperm and angiosperm
pollen, dinoflagellate cysts and other marine and freshwater algae. This study presents the dinoflagellate cyst
assemblages recovered from the lower part of the section. The biostratigraphic index dinoflagellate cysts taxa
suggest an early Albian age for the lower part of the Kachaike Formation and the assemblages are attributed to
the Muderongia tetracantha Interval Zone (Helby). The dominance of well preserved pollen and spores together
with the presence of dinoflagellate cysts, suggest that the lower levels of the Bajo Comisión section were deposited
in marine shallow waters, in agreement with the sedimentary facies.