The upper Hauterivian–Barremian (Lower Cretaceous) Arrifes section (Algarve Basin, Southern Portugal): A palynostratigraphic and palaeoenvironmental approach

• Autor(a) principal: Mendes, Márcia
• Data de Publicação: 2023
• Outros Autores: Descamps, Gabrielle S., Fernandes, Paulo, Lopes, Gilda, Jorge, Raul Carlos G.S., Pereira, Zélia
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.1/19187
• topic: Hauterivian-Barremian; Shallow marine carbonates; Dinoflagellate cysts; Palynofacies; Algarve Basin

Integrated sedimentological, palynological, and palynofacies analyses of the Arrifes section in the central Algarve Basin (southern Portugal) provided new information on the age and environments of this Lower Cretaceous sequence. The sedimentary succession at the Arrifes section consists of fossiliferous inter-bedded limestones, marly limestones, and marls, dated as latest Hauterivian to late Barremian age (Lower Cretaceous) based on key dinoflagellate taxa. During this interval, the Arrifes area records cli-matic shifts and, multiple sea-level fluctuations; overall deposition was in shallow subtidal to intertidal settings, with deposition of carbonate and marly sediments. During the latest Hauterivian to earliest Barremian interval, an evident sea-level fall culminated in the subaerial exposure of the local carbonate ramp with increased influx of clastic sediments. However, during the Barremian, both sedimentological and palynological analyses suggest an overall deepening of the water depth towards the top of the section. These overall increase in the water column are confirmed by oscillation of terrestrial/marine palynomorph groups and supported by dinosaur track levels at the top of the succession; the latter indicate that sedimentation occurred in intertidal to subtidal environments. Finally, an attempt was made to correlate the Arrifes section with other sections from the Algarve Basin, as well as with broader region. These new data suggest a setting in the Tethyan basin influenced during the latest Hauterivian to the end of the Barremian. These new data allow local correlations and new palynological ages and paleoenvironmental interpretations for the Lower Cretaceous succession of the Algarve Basin.(c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).