Paleobotanical and palynological analysis of Faxinal Coalfield (Lower Permian, Rio Bonito Formation, Paraná Basin), Rio Grande Do Sul, Brazil

The sedimentary section exposed at the Faxinal Coalfield bears abundant plant fossil remains distributed within a tonstein level, interlayered in a section mainly comprised by siltstones and coal deposits of the Rio Bonito Formation, Lower Permian, Paraná Basin, Brazil. This contribution presents a paleobotanical taxonomic updating of this coalfield based on an in-depth revision of available data as well as the direct analysis from material deposited in paleontological collections (published and unpublished). According to this reevaluation, the Faxinal Coalfield bears 15 paleobotanical taxa, comprised mainly by leaves of Glossopteridales, composing a typical coal-forming flora. New palynological results from this section are derived from five associated levels, which revealed distinct assemblages comprising 30 taxa of spores, 21 of pollen grains and 3 related to algae elements. The associations are compatible with the Glossopteris/Rhodeopteridium Zone and with the Protohaploxypinus goraiensis Subzone (base of the Vittatina costabilis Zone), related to the Cisuralian, Lower Permian (late Sakmarian/early Artinskian). Stratigraphical considerations are given based on comparison with other neighboring sections, as well as with a regional erosion surface recognized in this outcrop.

► Paleobotanical and palynological context from Faxinal Coalfield.
► Glossopteris/Rhodeopteridium Phytozone.
► Protohaploxypinus goraiensis Subzone (base of the Vittatina costabilis Palinozone).
► Palynostratigraphic analysis showed rare transition elements between PgSz and LvZ.
► Uppermost portion of the Rio Bonito Formation, just below the SB3 sequence boundary.