O papel das intrusões de soleiras e diques de diabásio na gênese de rotas de migração e armadilhas de hidrocarbonetos, em área de ocorrências de arenitos asfálticos da Formação Piramboia, região de Guareí - SP, Bacia do Paraná

Abstract

The current study consists in the analysis of tar sandstones occurrences near Guareí-SP, mostly of the Piramboia Formation and locally of the Rio Bonito Formation (Triassic and Permian of the Paraná Basin, respectively) in an attempt to set a tectonostratigraphic framework, as well the processes and timing which controlled their accumulations, emphasizing migration and traps formation associated to intrusive rocks. Therefore, the study took as a basis in various scales of observation ranging from the analysis of potential methods (gravimetry and magnetometry) and remote sensing (SRTM images) to the outcrop scale, and it included seismic interpretation of 2D lines, analysis of geological maps and well correlation. It uses concepts of unconventional petroleum systems and methodologies that have been applied in basins from Norway, UK and South Africa, linking genetically the emplacement of sills and dikes with associated structures in the formation and / or enhancement of migration pathways and hydrocarbon traps. Seismic facies were distinguished for the diabase sills according the classifications of Planke et al. (2005) and Hansen et al. (2004), that reveal a tangled network thresholds (composed and complex sills) which intrude the entire local stratigraphy plus the recognition and mapping of associated structures, such as forced folds and faults in a concentric pattern, radial and polygonal. The occurrences are set preferably in synclines controlled by normal faults just above saucer shaped sills that intrude the Itararé Group packages. The correlation of the data and different scales used say that the structural framework that sets the area of the occurrences is complex, exhibiting a major tectonic factor in response to sustained stress on the basin throug its evolution, and other additional and deformational associated to the intrusion of diabase sills and dikes during the Magmatism Serra Geral (Early Cretaceous).