Primeval Aptian marine incursions in the interior of Northeastern Brazil following the Gondwana breakup

Abstract 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.