Neumann, Virgínio HenriqueBarbosa, José AntônioSilva, Maria Valberlândia NascimentoFilho, Mário de Lima2010-02-242010-02-242009Geologos vol. 15 (2), 2009, pp. 103-113.1426-8981http://hdl.handle.net/10593/160New data are presented for three formations (Itamaracá, Gramame and Maria Farinha) and two boundaries (Campanian/Maastrichtian and Maastrichtian/Danian) in the Olinda Sub-basin of the Paraíba Basin. Currently accepted facies models, sequence stratigraphy characterizations, and stable-isotope data of carbon and oxygen are reviewed. The carbonate cement of the Itamaracá Formation sandstones shows carbon- and oxygen-isotope ratios consistent with a shallow-marine depositional environment: δ18O ranges from -0.8 to -2.7‰ PDB, and δ13C ranges from +1 to +2‰ PDB. Within the Itamaracá Formation, a maximum flooding surface at the Campanian/Maastrichtian transition has been identified. During the Maastrichtian, a Highstand System Tract was deposited, which shows an increase in temperature and marine bioproductivity as recorded by stable-isotope values (δ18O from -3 to -5‰ PDB, and δ13C values of -1.2, -0.3, 0.1 and +2.3‰ PDB). Just below the K/Pg boundary, the O-isotope signal indicates three warming phases, alternating with four cooling phases.NE BrazilCretaceous/Palaeogene boundarycarbon isotopesoxygen isotopesArtykuł