Cryogenian glaciostatic and eustatic fluctuations and massive Marinoan-related deposition of Fe and Mn in the Urucum District, Brazil

Autor(es):Mostrar menos -

Freitas, B. T. ^[1] ; Rudnitzki, I. D. ^[2] ; Morais, L. ^{[3, 4]} ; Campos, M. D. R. ^[1] ; Almeida, R. P. ^[4] ; Warren, V, L. ; Boggiani, P. C. ^[4] ; Caetano-Filho, S. ^[4] ; Bedoya-Rueda, C. ^[4] ; Babinski, M. ^[4] ; Fairchild, T. R. ^[4] ; Trindade, R. I. F. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Fac Tecnol, BR-13484332 Limeira, SP - Brazil

^[2] Univ Fed Ouro Preto, Dept Geol, BR-35400000 Ouro Preto, MG - Brazil

^[3] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508090 Sao Paulo, SP - Brazil

^[4] Inst Geociencias, BR-05508080 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: GEOLOGY; v. 49, n. 12, p. 1478-1483, DEC 1 2021.
• Citações Web of Science: 0

Resumo

Global Neoproterozoic glaciations are related to extreme environmental changes and the reprise of iron formation in the rock record. However, the lack of narrow age constraints on Cryogenian successions bearing iron-formation deposits prevents correlation and understanding of these deposits on a global scale. Our new multiproxy data reveal a long Cryogenian record for the Jacadigo Group (Urucum District, Brazil) spanning the Sturtian and Marinoan ice ages. Deposition of the basal sequence of the Urucum Formation was influenced by Sturtian continental glaciation and was followed by a transgressive interglacial record of >600 m of carbonates that terminates in a glacioeustatic unconformity. Overlying this, there are up to 500 m of shale and sandstone interpreted as coeval to global Marinoan glacial advance. Glacial outwash delta deposits at the top of the formation correlate with diamictite-filled paleovalleys and are covered by massive Fe and Mn deposits of the Santa Cruz Formation and local carbonate. This second transgression is related to Marinoan deglaciation. Detrital zircon provenance supports glaciostatic control on Cryogenian sedimentary yield at the margins of the Amazon craton. These findings reveal the sedimentary response to two marked events of glacioeustatic incision and transgression, culminating in massive banded iron deposition during the Marinoan cryochron. (AU)

• Processo FAPESP: 16/19736-5 - Abordagens quantitativas de depósitos fluviais de grande porte: geologia de campo integrada a modelos 3D de afloramentos obtidos por fotogrametria
• Beneficiário: Bernardo Tavares Freitas
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/22099-0 - Mecanismos de biomineralização e paleobiologia de microfósseis eucariontes neoproterozóicos da Faixa Paraguai Sul
• Beneficiário: Luana Pereira Costa de Morais
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 16/06114-6 - O Sistema Terra e a evolução da vida durante o Neoproterozoico
• Beneficiário: Ricardo Ivan Ferreira da Trindade
• Modalidade de apoio: Auxílio à Pesquisa - Temático