Palynology of Bonito and Barro Branco coal seams from Rio Bonito Formation (Lower Permian of Paraná Basin) in the Criciúma coal region, southernmost Brazil

Abstract

Seven coal seams were sampled from several mines and outcrops of the Rio Bonito Formation, Bonito and Barro Branco coal seams, in the coal mining region of Criciúma, Paraná Basin, Santa Catarina State (Brazil), for a detailed palynostratigraphic study. The coal seams sampled yield abundant, diverse and moderately to well preserved palynological assemblages. A total of twenty-seven spore species, fourteen pollen species and four microplanktonic or clorophyceae algae and fungi species were identified. The palyno-assemblages recovered in the Bonito and Barro Branco coal seams are assigned to the Vittatina costabilis Interval Zone, Protohaploxypinus goraiensis Subzone of the Paraná Basin, of Asselian? to Artinskian age (Lower Permian). The microflora assemblages identified in these coal seams are very similar in composition, presenting a dominance of arborescent and herbaceous lycophytes. The Barro Branco coal seam shows a relatively higher frequency of algae like composition than in the Bonito coal seam, suggesting a possible fluvial or lagoonal facies influence.