Middle-Upper Devonian palynofloras from Argentina, systematic and correlation

Abstract

This investigation documents the first palynoassemblage spanning the Middle-Upper Devonian from four outcropping sections located in northwestern Argentina. The recovered material includes fairly well-preserved palynomorphs, both from marine and continental origin, including acritarchs, prasinophytes, cryptospores, spores and chlorophytes. In two of the four studied localities chitinozoans were encountered, whilst only one of them have yielded scolecodonts. Five new species are described including one acritarch specimen: Gorgonisphaeridium impexus sp. nov., two prasinophytes: Cymatiosphaera robusta sp. nov. and Pterospermella simplex sp. nov., one chitinozoan: Angochitina plicata sp. nov. and one miospore species: Apiculatasporites ruptus sp. nov. Hierarchical cluster analysis recognize two well-differentiated palynofloras in Argentina for the Early and Middle-Late Devonian. A poor correlation with known Devonian biostratigraphical schemes from Gondwanan and peri Gondwanan regions, support the theory of an endemic flora in northwestern and eastern Gondwana even during the Middle and Late Devonian. The palynoassemblage studied here provides an important source of reference to improve former strata correlation in the Tarija and neighbouring basins.