New findings of the Lueckisporites virkkiae Zone (late Cisuralian-Guadalupian) in the Serra do Rio do Rastro and neighboring localities (Paraná Basin) in Santa Catarina, Brazil

DI PASQUO, M.M.; SOUZA, P.A.

Mendoza

Congreso; 4th International Palaeontological Congress; 2014

IANIGLA

New palynological data is documented from some deposits of the Passa Dois Group (Irati, Serra Alta, Teresina and Rio do Rasto formations), in Santa Catarina, Brazil. The well constrained Irati Formation (basis of the Passa Dois Group) is akin to the late Artinskian by different paleontological (including palynology) and radiometric data. Although, the overlying units are palynological poorly known, comprising few citations of pollen grains with no illustrations or description, mainly due to the rarity of these occurrences as well as their poor preservation. A comprehensive sampling has been done from the Serra Alta, Terezina and Rio do Rastro formations in the Serra do Rio do Rastro and neighboring region in Santa Catarina State, revealing new records with biostratigraphic significance. The Serra Alta Formation is transitionally deposited over the Irati Formation and well exposed at the Point 9 of the classic White´s Column in the way to the top of the Serra do Rio do Rasto. Currently there is a mining development of slabs from a thick section (ca. 30 meters) composed of mudstones, shales, siltstones and sandstones. Eleven of the twenty two samples collected yielded fairly well preserved palynomorphs. The whole assemblage is dominated by pollen grains and subordinated spores and Botryococcus. Diagnostic species of the Lv Zone in the Paraná Basin were recorded (e.g. Corisaccites alutas, Guttulapollenites hannonicus, Klausipollenites schaubergerii, Lueckisporites virkkiae, Lueckisporites spp., Marsupipollenites striatus, Staurosaccites spp., Vittatina spp., Weylandites lucifer, and the spores Convolutispora uruguaiensis, Polypodiisporites mutabilis and Reticuloidosporites warchianus). Other sections exposed in the Urubici region, stratigraphically below the Botucatu Formation were also sampled (Corvo Branco Hill and Sete Quedras localities, both in Urubici Municipality). From the first locality, the palynoassociation is well preserved and dominated by pollen grains (e.g., Corisaccites alutas, Lueckisporites virkkiae, Lueckisporites spp., Lunatisporites variesectus, Protohaploxypinus varius, P. limpidus, Scheurigipollenites ovatus, Staurosaccites spp., Vittatina spp., Weylandites lucifer), and subordinated spores (Convolutispora uruguaiensis, Polypodiisporites secoensis, Lophotriletes cf. parryensis) and Botryococcus. Scarce and poor preserverd palynomorphs were retrieved from four samples from Sete Quedas at Urubici. These new records are very similar to the Serra Alta Formation association, and are assigned to the Lueckisporites virkkiae Zone. [CNPq Project 402873/2012-2]