Microbialite fields developed in a protected rocky coastline: The shallow carbonate ramp of the Aptian Romualdo Formation (Araripe Basin, NE Brazil)

Autor(es)

Varejao, F. G. ^[1] ; Fuersich, F. T. ^[2] ; Warren, V, L. ; Matos, S. A. ^[3] ; Rodrigues, M. G. ^{[3, 4]} ; Assine, M. L. ^[4] ; Sales, A. M. F. ^[5] ; Simoes, M. G. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, Dept Geol Aplicada, Ave 24A, 1515, BR-12506900 Rio Claro - Brazil

^[2] Friedrich Alexander Univ Erlangen Nurnberg, FG Palaoumwelt, GeoZentrum Nordbayern, Loewenichstr 28, D-91054 Erlangen - Germany

^[3] Univ Estadual Paulista, Inst Biociencias, Dept Zool, BR-18618000 Botucatu, SP - Brazil

^[4] Warren, L., V, Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, Dept Geol Aplicada, Ave 24A, 1515, BR-12506900 Rio Claro - Brazil

^[5] Univ Reg Cariri, Dept Ciencias Biol, Campus Pimenta 1161, BR-63100000 Crato - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SEDIMENTARY GEOLOGY; v. 389, p. 103-120, JUL 1 2019.
• Citações Web of Science: 0

Resumo

The Aptian Romualdo Formation is a siliciclastic-dominated sedimentary unit recording the last marine ingression within the Cretaceous interior basins of northeastern Brazil. At the western margin of the Araripe Basin, rocks of the Romualdo Formation are mainly represented by carbonates resting abruptly over the Proterozoic crystalline basement. Detailed mapping and stratigraphic analysis revealed two stromatolite fields that were described and discussed for the first time. Several bioherms, biostromes and isolated stromatolites characterized by distinct microbialite morphologies associated with echinoid-rich strata have been identified, suggesting that hypersalinity, water depth and hydraulic conditions were the main factors controlling stromatolite morphogenesis. A cm-thick amalgamated bivalve rudstone, resting directly on the basement and representing a shell concentration formed above the fair-weather wave base was also recorded. Based on the regional distribution of the stromatolite types and associated sedimentary fades, we interpret the depositional environment as a local low gradient carbonate ramp deepening to the east. Our data robustly indicated that the western rocky shorelines of the Araripe Basin during the Aptian were populated by microbial mats and stromatolites in a condition analogous to the modern world-famous Hamelin Pool, Shark Bay, Western Australia. Finally, the development of stromatolites and echinoid-bearing microbialites at the western margin of the basin may be correlated with the formation of bakevelliid- and cassiopid-rich shell beds in the upper part of the Romualdo Formation at the eastern margin. (C) 2019 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 14/00519-9 - Centralidades do lazer noturno na cidade de São Carlos-SP e as relações de interface
• Beneficiário: Tiago Ferreira Lopes Machado
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 16/13214-7 - Abordagem multi-indicadores do sistema misto carbonático-siliciclástico da Formação Crato: evolução sedimentar, paleogeografia e tectônica
• Beneficiário: Filipe Giovanini Varejão
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 17/20803-1 - Contexto Estratigráfico e Paleoambiental das Assembleias de Macroinvertebrados da Formação Romualdo, Cretáceo da Bacia do Araripe, e suas Implicações Paleogeográficas
• Beneficiário: Suzana Aparecida Matos da Silva
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 18/01750-7 - Bivalves Bakevelliidae da Formação Romualdo (andar Alagoas, Cretáceo Inferior), Bacia do Araripe, Brasil: significado paleoambiental e paleogeográfico
• Beneficiário: Mariza Gomes Rodrigues
• Modalidade de apoio: Bolsas no Brasil - Mestrado