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The Aptian–Albian interval is characterized by significant paleoclimatic, paleoceanographic, and paleogeographic changes, which in turn affected the distribution and evolution of marine ecosystems. Despite the importance of such studies, there have been few correlations between Aptian–Albian sections of the Tethys Sea and those of the South Atlantic Ocean. This interval, including the Aptian–Albian transition, is preserved in the deposits of the Riachuelo Formation (Sergipe–Alagoas Basin, Brazil) located in the South Atlantic Ocean; therefore, this location was chosen for drilling four new cores. The goals of this paper are as follows: (1) to explain the drilling operation carried out in the deposits of the Riachuelo Formation and the methods used; (2) to present a brief lithostratigraphic characterization of the holes and the paleomagnetic data of core SER-03; and (3) to describe the high potential of the cores recovered for additional investigation in the future. The lithostratigraphic units of the SER-01 core consist mainly of coarse- to fine-grained sandstone, shales, marls, and mudstones; the SER-02 core was excluded due to low recovery; the SER-03 core is mainly composed of fine-grained sediments (shale, marls, and packstone) and bears some ammonite shells; the lithology of core SER-04 is mainly sandstones. Magnetic susceptibility values (χlf and χhf) and frequency-dependent susceptibility (χfd) data suggest that the section is located within the Cretaceous Normal Superchron. Future studies on these cores integrating micropaleontological, paleoichnological, geochemical, stratigraphic, and paleomagnetic (e.g., relative intensity) data will allow for a better understanding of paleoceanographic and paleogeographic events related to the early evolution of the South Atlantic Ocean and how these events correlate to similar events in Tethyan sections.

This study reports a set of primeval marine incursions identified in the two drill cores (1PS-06-CE and 1PS-10-CE) recovering the Barbalha Formation, Araripe Basin, Brazil. Based on multi-proxy approach involving stratigraphy, microbiofacies, ichnofossils, and microfossils found in the Barbalha Formation, three short-lived marine incursions were identified, designated Araripe Marine Incursions (AMI). The AMI-1 and AMI-2, which occur within the shaly Batateira Beds (lower part of the Barbalha Formation), were identified through the occurrence of benthic foraminifera, calcareous nannofossils, dinocysts, and a mass mortality event of non-marine ostracods. The AMI-3 is recorded in the upper part of the Barbalha Formation and its identification was based on occurrence of ichnofossils and planktic foraminifers. The presence of planktic foraminifera genus Leupoldina suggests, for the first time in the basin, an early Aptian/early late Aptian age for the deposits and allows correlation of this unit with global foraminifera biozonation. Our findings have implications for the breakup of the Gondwana Supercontinent, as these incursions represent the earliest marine-derived flooding in the inland basins of Northeastern Brazil.

Brazil is a country of continental proportions, with enormous geological wealth and potential for new discoveries based on innovative research techniques. There are demands for the increase of knowledge on country’s geology. The 48 th Brazilian Congress of Geology (48 th BCG) will play an important role in bringing this knowledge together from academia, industry, professionals and society through courses, talks and discussions.