Caracterização icnológica do Membro Jaguariaíva no testemunho 2-TB-1-PR (Devoniano da Bacia do Paraná)

Abstract

The Jaguariaíva Member, basal unit of the Ponta Grossa Formation, Lower Devonian of the Paraná Basin, is constituted essentially by claystones and laminated clayey siltstones, disposed in gradational contact on the sandstones of the Furnas Formation. In addition to having a broad paleontological record, consisting of paleoinvertebrates characteristic of the Malvinokaffric Realm, microfossils, plant fossils and trace fossils, the Jaguariaíva Member is characterized by the highest ichnodisparity values among the Devonian strata of the Paraná Basin.. Although several works of an ichnological nature have been carried out for the Ponta Grossa Formation, few are the studies that focus on subsurface data. Therefore, this work aimed to describe the sedimentary facies and the ichnological content of the interval corresponding to the Jaguariaíva Member (432 to 345 m), from the borehole core 2-TB-1 -PR, acquired on the eastern edge of the Paraná Basin, in the municipality of Tibagi, Paraná. The description of the drill core 2-TB-1-PR allowed the recognition of the two formations of the Paraná Group, which are represented by the top of the Furnas Formation (432.6 - 451.6 m), in contact with the base of the Ponta Grossa (345.0 – 432.6), represented by Member Jaguariaíva. In this study it is reported the Skolithos, Zoophycos, Palaeophycus, Chondrites, Rhizocorallium – Palaeophycus, Phycosiphon, Asterosoma, Asterosoma – Zoophycos and Asterosoma – Rhizocorallium and Glossifungites ichnofabrics. These ichnofabrics correspond to Skolithos, Glossifungites and Cruziana ichnofacies in proximal, archetypal, and distal expressions. Finally, the sedimentary and ichnological association allowed framing the paleodepositional context of the Jaguariaíva Member, in a configural platform, under shallow marine conditions, including the transitional shoreface, transitional offshore and offshore.