Análise icnológica do permiano inferior da Bacia do Paraná e sua aplicabilidade em estudos de dinâmica da linha de costa

Abstract

This thesis approaches the application of ichnological data as stratigraphic signatures to infer paleocological and paleoenviromental parameters. In this way, the suite and ichnofacies changes through the early Permian succession of the Paraná Basin permitted to infer the coastline relative dynamics in higher scale (3ra and 2 order). The study of this succession included the lithological and ichnological composition of the Rio Bonito, Palermo, and Irati formations recovered in different cores. This analysis permitted to identify signatures of paleoenviromental stress (depleted oxygen and salinity) evidenced by the high density of Palaeophycus in the Rio Bonito deposits and stratigraphic signatures such as autogenic and allogenic surfaces demarked by Glossifungites suites in the Rio Bonito and Palermo formations, respectively. The vertical distribution of ichnofacies from base to top (impoverishes Skolithos– archetypal Cruziana– distal Cruziana (lower ichnodiversity) ichnofacies), and distinctive sedimentologic signatures (estuarine – lower shoreface – offshore subenvironments) reinforcing the transgressive character of the early Permian succession. Thus, this thesis demonstrates the utility of the ichnological data for resolving stratigraphic, paleoenvironmental and paleoecological questions.