Otaviano Carneiro da Cunha Neto
2003
Citations
1
Influential Citations
36
Citations
Journal
Brazilian Journal of Geology
Abstract
The aim of this paper is the tertiary mixed siliciclastic-carbonate platform in the Potiguar Basin. The main goal is to address answers to some questions about mixed siliciclastic-carbonate settings, such as depositional shelf dynamics, lateral and vertical facies and their response to sea level variations, questions that have seldom been dealt with or published. The study area covers over 2500 km 2 , it is located in the basin’s submersed portion, it has as its offshore limit the 200 m bathymetry and it concentrates only on the coastal, shelf and upper slope facies. The section of this study comprises part of the Neogenic sedimentary rocks, which is composed of three lithostratigraphic units known as the Tibau Formation (sandstones and conglomerates), the Guamare Formation (limestones), and the Ubarana Formation (marine shales). These units make up a large regressive cycle, starting at the Late Campanian through to Holocene. They form a seaward thickening coastal-shelf-slope-basin system. The present paper focuses on a section deposited on the shelf after an Early Miocene erosional unconformity whose angular feature is easily recognized in the submersed portion of the Potiguar Basin, as well as in other basins on the Brazilian coast. The method used in the present study was the integrated stratigraphic analysis, based on sequence stratigraphy concepts through seismic stratigraphy, well logs and biostratigraphy. The integrated approach of the data allowed a subdivision of the section under study in 3 rd order depositional sequences, which were detailed in system tracts and higher frequency sequences. The stratigraphic framework obtained allowed for the proposal of a more refined depositional model for the Neogenic mixed platforms in the area under this study.