2020-03-052020-03-052019-12-16REIS, Leonardo Nogueira dos. Petrografia e proveniência sedimentar do contato entre as formações Longá e Poti na região de Floriano (PI) e Barão de Grajaú (MA), Mesodevoniano-Eocarbonífero da Bacia do Parnaíba. Orientador: José Bandeira Cavalcante da Silva Júnior. 2019. 64 f. Trabalho de Curso (Bacharelado em Geologia) - Faculdade de Geologia, Instituto de Geociências, Universidade Federal do Pará, Belém, 2019. Disponível em: https://bdm.ufpa.br:8443/jspui/handle/prefix/3078. Acesso em:.https://bdm.ufpa.br/handle/prefix/3078The migration of the Gondwana paleocontinent to the South Pole during the Mesodevonian-Carboniferous transition generated a series of glacial events that provided major paleoclimatic and paleoenvironmental changes around the globe. In Brazil, the Canindé Group, which outcrops on the eastern and western edges of the Parnaíba Basin, corresponds to the most significant record of this range, and is composed of the Itaim, Pimenteiras, Cabeças, Longá and Poti formations. Although the Longá and Poti formations have their lithostratigraphic sequences well defined in the literature, there was a need for more detailed studies on the contact zones between these units. In this work, the petrography and sedimentary provenance of sandstones corresponding to these two units were analyzed. The definition of the facies associations followed previous works proposal, classifying three facies associations for the treated samples: Longá Formation storm wave dominated platform (FA1), Poti Formation delta front (FA2) and wave and tide dominated platform also from Poti Formation (FA3). Petrographically, subarkoses and quartzarenite lithotypes were defined for FA1, subarkoses for FA2, as well as quartzarenites and subarkoses for FA3. The sedimentary provenance of the sandstones of this range were determined from the cathodoluminescence (CL) analysis of detrital quartz grains and paleocurrents directions. Predominantly, dark blue CL quartz domain was observed, which defined probable source areas dominated by plutonic and high temperature metamorphic rocks. In addition to paleocurrent data extracted from FA2, which tended to migrate bed forms to WNW, it was interpreted that the sedimentary provenance of these records is associated with rocks belonging to Borborema Province, east of the eastern border of the Parnaíba Basin. However, it was considered that these records may also be associated with the rocks of the São Francisco Craton, located southeast of the eastern border of the basin.Acesso AbertoProveniência SedimentarBacia do ParnaíbaFormação LongáFormação PotiCNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIATrabalho de Curso - Graduação - Monografia