Systematics and paleoecology of the bivalves of the crato formation (Lower Cretaceous), Northeastern Brazil: paleoenvironmental and paleogeographic significance

• Grant number: 17/22036-8
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): March 01, 2018
• Effective date (End): September 30, 2019
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Acordo de Cooperação: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Marcello Guimarães Simões
• Grantee: Victor Ribeiro da Silva
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The Aptian Crato Formation is a 65m-thick, carbonate-siliciclastic-evaporitic succession in the Araripe Basin, northeastern Brazil, that was generated during the Gondwana break-up. It is regarded as a world-class Konservat-Lagerstätten where numerous fossil groups (plants, vertebrates and invertebrates) are exceptionally preserved. The vertical succession encompasses siliciclastic and carbonate rocks deposited in an open to close lacustrine system, followed by mixed mud intertidal flat, and supratidal sabkha deposits. Therefore, the succession records a gradual increase in salinity towards to the top, culminating in the evaporites of the Ipubi Formation. Despite of that, there are many controversies about the paleoenvironmental conditions, particularly about the brief marine incursions during the generation of limestones, sandstones and shales that were deposited immediately above the fossil-rich, laminated carbonates. In this context, this project aims to formally describe the bivalve fauna recorded in a ~60-cm-thick bed of yellowish, massive sandy siltstone located 40 cm above the basal laminated limestone bank. The main issues to be verified are: a- the taxonomic composition of the fauna; b- the paleobiogeographic affinities of those bivalves, and c- the depositional conditions that generate bivalve-rich beds. The hypothesis to be verified is that one related to the occurrence of short-lived marine ingressions into the Araripe Basin prior the deposition of the Ipubi Formation. Such assumption has profound implications to the paleogeographic reconstructions of the Araripe Basin, during the South Atlantic Ocean opening. To achieve the goals above, a large bivalve collection (>150 specimens) is already available to study at the IBB/UNESP, and will be investigated using standard paleontological procedures. Finally, this project could add to the knowledge about the main direction of the marine ingressions in the Lower Cretaceous of the Araripe Basin, a key issue concerning the geology of the sedimentary basins of the northeastern interior of Brazil. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

FILIPE GIOVANINI VAREJÃO; VICTOR RIBEIRO SILVA; MARIO LUIS ASSINE; LUCAS VERÍSSIMO WARREN; SUZANA APARECIDA MATOS; MARIZA GOMES RODRIGUES; FRANZ THEODOR FÜRSICH; MARCELLO GUIMARÃES SIMÕES. Marine or freshwater? Accessing the paleoenvironmental parameters of the Caldas Bed, a key marker bed in the Crato Formation (Araripe Basin, NE Brazil). BRAZILIAN JOURNAL OF GEOLOGY, v. 51, n. 1, 2020-12-21. (17/20803-1, 18/01750-7, 16/13214-7, 14/00519-9, 17/22036-8)

DA SILVA, VICTOR R.; VAREJAO, FILIPE G.; MATOS, SUZANA A.; FUERSICH, FRANZ T.; SKAWINA, ALEKSANDRA; SCHNEIDER, SIMON; WARREN, LUCAS V.; ASSINE, MARIO L.; SIMOES, MARCELLO G.. Cratonaia novaolindensis gen. et sp. nov. (Unionida, Silesunionoidea) from the Aptian of Brazil (Araripe Basin), and its implications for the early evolution of freshwater mussels. CRETACEOUS RESEARCH, v. 107, MAR 2020. (14/00519-9, 16/13214-7, 17/20803-1, 17/22036-8)

DA SILVA, VICTOR R.; VAREJAO, FILIPE G.; MATOS, SUZANA A.; RODRIGUES, MARIZA G.; FURSICH, FRANZ T.; SKAWINA, ALEKSANDRA; SCHNEIDER, SIMON; WARREN, V, LUCAS; ASSINE, MARIO L.; SIMOES, MARCELLO G.. New freshwater mussels (Bivalvia, Unionida) with potential trigonioidid and hyriid affinities from the Early Cretaceous of Brazil. GEOBIOS, v. 61, p. 41-54, AUG 2020. (14/00519-9, 17/22036-8, 16/13214-7, 18/01750-7, 17/20803-1)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

SILVA, Victor Ribeiro da. Systematics of the bivalves (Mollusca) from the Crato Formation (Lower Cretaceous), NE Brazil and its paleoenvironmental significance. 2019. Master's Dissertation - Universidade Estadual Paulista (Unesp). Instituto de Geociências e Ciências Exatas. Rio Claro Rio Claro.