Tectonic activation, source area stratigraphy and provenance changes in a rift basin: the Early Cretaceous Tucano Basin (NE-Brazil)

Autor(es)

Figueiredo, Felipe T. ; Almeida, Renato P. ; Freitas, Bernardo T. ; Marconato, Andre ; Carrera, Simone C. ; Turra, Bruno B.

• Tipo de documento: Artigo Científico
• Fonte: BASIN RESEARCH; v. 28, n. 4, p. 433-445, AUG 2016.
• Citações Web of Science: 9

Resumo

Changes in sandstone and conglomerate maturity in tectonically active basins can be considered either as the product of climatic change or of tectonic restructuring of the feeder drainage system. Besides these regional controls, changes in the configuration of local sources can expressively affect basin fill composition. The Early Cretaceous fluvial successions of the Tucano Basin, a rift basin in northeastern Brazil related to the South Atlantic opening, contain one such case of abrupt change in maturity, marked by the passage from pebbly sandstone and conglomerate rich in quartz and quartzite fragments (Neocomian to Barremian Sao Sebastiao Formation) to more feldspathic pebbly sandstone and conglomerate bearing pebbles of varied composition (Aptian Marizal Formation). Systematic analysis of stratigraphic and spatial variation in palaeocurrents and composition of pebbles and cobbles from both units, integrated with the recognition of fluvial and alluvial fan deposits distribution, revealed an abrupt decrease in maturity during the passage from the Sao Sebastiao Formation to the Marizal Formation. This change is explained by exhumation of basement rocks and erosional removal of originally widespread Silurian to Jurassic sandstone and conglomerate units which were a major source of reworked vein quartz and quartzite pebbles to the Sao Sebastiao Formation. Basin border faults activation during the deposition of the Marizal Formation caused adjacent basement uplift above the local erosional base level at the basin borders, whereas during the Sao Sebastiao Formation deposition, the basin border fault scarps probably exposed mineralogically mature sedimentary units. The proposed model has important implications for interpreting changes in sediment maturity in rift basin successions, as similar results are expected where activation of basin border faults occurs after the erosional removal of older sedimentary or volcanic units that controlled syn-rift successions composition. (AU)

• Processo FAPESP: 09/53363-8 - Arquitetura de depositos aluviais das formacoes sao sebastiao e marizal (sin- e pos-rift) das sub-bacias tucano central e norte (cretaceo - ba).
• Beneficiário: Renato Paes de Almeida
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/01825-3 - Relação de fácies e heterogeneidades de microescalas em análogos de reservatórios de sistemas fluviais das bacias do Camaquã (RS) e Tucano Central (BA)
• Beneficiário: Liliane Janikian Paes de Almeida
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 10/51559-0 - Evolucao tectono-sedimentar de sistemas aluviaisi pos-rift: o caso da formacao marizal (aptiano) nas sub-bacias do tucano norte e central
• Beneficiário: Bernardo Tavares Freitas
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 09/51766-8 - Análise de proveniência da formação Marizal, sub-bacia do Tucano-Central, Cretáceo, BA
• Beneficiário: Simone Campos Carrera
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 09/52807-0 - Comparacao entre a evolucao tectono-sedimentar das sub-bacias do tucano norte e central.
• Beneficiário: Felipe Torres Figueiredo
• Modalidade de apoio: Bolsas no Brasil - Doutorado