Print this pageStratigraphy and Paleogeography of the Lower Permian Rio Bonito and Palermo Formations, Paraná Basin, Southern Brazil
The Rio Bonito and Palermo formations have been the target of sedimentologic and stratigraphic studies since the beginning of the last century, when interest in the coal deposits and petroleum reservoirs motivated research on the eastern and southern borders of the Paraná Basin. The study area extends for 350 to 400 km and is located in Paraná and Santa Catarina, southern Brazil. Approximately 65 wells form the database, with 13 cored wells within the succession that makes up the studied sequences. Cores and well logs were obtained from the Brazilian Geological Survey (CPRM). The detailed core descriptions provided sedimentological and ichnological data. Regional cross sections were made in order to integrate data within a sequence stratigraphic framework and facilitate the interpretation of the evolution of the depositional systems. This study aims to refine depositional interpretations, stratigraphic relationships and the paleogeography of paralic to shallow-marine deposits based upon an integrated dataset. Furthermore, it seeks to clarify the temporal and spatial organization among the different facies associations within a sequence stratigraphy perspective on a regional scale. During the Early Permian, the eastern border of the Paraná Basin represented a broad epicontinental sea. It was established on a low-gradient shelf with a proximal-distal trend oriented approximately north-northeastern to south-southwestern. Inasmuch as the depositional systems are widespread, the temporal correlations in the subsurface can be difficult to define within a setting where small sea-level changes promote abrupt shifts of facies.
AAPG Search and Discover Article #90100©2009 AAPG International Conference and Exhibition 15-18 November 2009, Rio de Janeiro, Brazil