Organic geochemical evidence for the transition of Aptian-Albian hypersaline environments into marine restricted seas: The South Atlantic oceanic northern gateway and its implications for the pre-salt deposits

Bastos, Lucas Pinto Heckert; Jagniecki, Elliot A.; Santos, Werlem Holanda dos; Cavalcante, Danielle da Costa; Menezes, Celma Jorge de; Alferes, Carmen Lucia Ferreira; Silva, Debora Bonfim Neves da; Bergamaschi, Sérgio; Rodrigues, R. F.; Pereira, Egberto

doi:10.1016/j.marpetgeo.2022.105632

Cited by 6 publications

(5 citation statements)

References 76 publications

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“…Despite having less resolved stratigraphies, nearby Aptian‐Albian epicontinental marine sites from the Parnaíba and São Luís basins, northeastern Brazil (Bastos et al., 2022), present similar thicknesses of black shale levels and TOC concentrations as those recorded during the Kilian sub‐event at the Sítio Sobradinho outcrop. In these regions, nCIE magnitudes are greater (∼4‰) than that at the Sítio Sobradinho outcrop.…”

Section: Discussionmentioning

confidence: 98%

“…Despite having less resolved stratigraphies, nearby Aptian-Albian epicontinental marine sites from the Parnaíba and São Luís basins, northeastern Brazil (Bastos et al, 2022), present similar thicknesses of black shale levels Herrle et al, 2004;Kennedy et al, 2017); (c) Poggio le Guaine section (Italy, Coccioni et al, 2014). We speculate that the peak nCIE, also characterized by enhanced C org burial (S2 interval), at the Sítio Sobradinho outcrop correlates with the recovery phase of deep ocean carbonate δ 13 C records.…”

Section: Tentative Global Correlationmentioning

confidence: 99%

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Fossil‐Bearing Concretions of the Araripe Basin Accumulated During Oceanic Anoxic Event 1b

Bom,

Kochhann,

Heimhofer

et al. 2023

Paleoceanog and Paleoclimatol

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Fossils from the Araripe Basin (northeastern Brazil) are known for their remarkable preservation of vertebrates and invertebrates, even including soft tissues. They occur in carbonate concretions within organic carbon‐rich strata assigned to the Romualdo Formation. Here we present integrated stable isotope, elemental and microfossil records from the Sítio Sobradinho outcrop, Araripe Basin, northeastern Brazil. Our results imply that black shales hosting fossil‐bearing carbonate concretions within the lower Romualdo Formation were deposited during Oceanic Anoxic Event (OAE) 1b (Kilian sub‐event). Our high‐resolution multi‐proxy approach allows identifying four phases of environmental evolution. After a pre‐event phase, an early phase (onset of the negative carbon isotope excursion—nCIE) of water column stratification and reduced oxygenation likely preconditioned the system for organic carbon burial and preservation. A second phase (peak nCIE) was characterized by an intensified hydrological cycle and continental runoff, as well as increased influx of terrestrial organic matter. High input of continent‐derived nutrients might have enhanced biological productivity in the epicontinental sea, ultimately leading to increased organic carbon fluxes and burial, as well as carbonate dissolution at the seafloor. All together, these paleoenvironmental conditions resulted in expansion of an oxygen minimum zone (OMZ), favoring taphonomic processes that led to the excellent preservation of diverse macro‐ and microfossils. The nCIE recovery phase was characterized by reduced nutrient supply and organic carbon burial. Organic carbon sequestration in such paleoenvironments likely contributed to the recovery (increase) of stable carbon isotope (δ13C) records in the deep ocean during the Kilian sub‐event of OAE 1b.

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Section: Discussionmentioning

confidence: 98%

Section: Tentative Global Correlationmentioning

confidence: 99%

Fossil‐Bearing Concretions of the Araripe Basin Accumulated During Oceanic Anoxic Event 1b

Bom,

Kochhann,

Heimhofer

et al. 2023

Paleoceanog and Paleoclimatol

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“…Despite the work already done, there is still no clear understanding of the paleoenvironmental evolution of the Codó Formation. In general, the studies have identified a lacustrine system with occasional marine incursions, generally at the top Antonioli & Arai, 2002;Bastos et al, 2014Bastos et al, , 2022Lindoso et al, 2016;Sousa et al, 2019;Bobco et al, 2023). On the other hand, some works recognized a lacustrine paleoenvironment without direct marine influence (Paz & Rossetti, 2001;Bahniuk et al, 2015).…”

Section: Paleoenvironmentsmentioning

confidence: 99%

“…Sousa et al (2019), through analyzes of the composition of organic matter and biomarkers, identified a saline to hypersaline paleoenvironment, with the influence of organic matter of marine origin. Bastos et al (2022) conducted a study involving biomarkers, nitrogen isotopes and organic carbon isotopes, revealing a sequence of events within the Codó Formation. Initially, they identified a high-saline environment with intermittent marine influxes, transitioning into a closed evaporitic system.…”

Section: Paleoenvironmentsmentioning

confidence: 99%

The critical role of accurate fossil identification: the case of the ostracods of the Codó Formation, NE Brazil

Coimbra,

Petró

2023

Rev. bras. paleontol.

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The Class Ostracoda comprises bivalve microcrustaceans with great diversity and abundance in the Lower Cretaceous paleolakes of Brazil and the world. With species generally well-preserved and of relatively short biochrons, it has provided high-resolution biostratigraphic frameworks that permit long-distance correlations. In this context, the Lower Cretaceous biozones of the NE Brazilian basins have allowed the establishment of correlations between coeval geological sections not only in this region but also with those of the Brazilian marginal basins, including the rocks of the pre-salt deposits, as well as with West African basins. In addition to biostratigraphy, these microfossils have proved indispensable in paleoenvironmental and paleogeographical analyses, including studies on the opening of the South Atlantic Ocean. However, some publications have emerged that, regrettably, exhibit errors in species identification and/or the accurate interpretation of biostratigraphic works. These mistakes have led to proposed modifications in both the biochron and geographic distribution of index taxa and taxonomic synonymizations that are incongruent with the current state of knowledge of the species. Consequently, these inaccuracies have given rise to erroneous biochronostratigraphic correlations and paleoenvironmental inferences. In this context, we meticulously examine the current understanding of the taxonomy of ostracods from the Codó Formation (NE Brazil), which is essential for the debate on the use of Lower Cretaceous ostracods in stratigraphy. Keywords: biostratigraphy, paleoecology, microfossils, Lower Cretaceous, Brazil.

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“…Ramos et al (2006), em estudos com ostracodes da Formação Codó na Bacia do Grajaú, notam diferença nas condições de salinidade, que por vezes chegam a ser hipersalinas. Bastos et al (2022) sugerem, através de dados geoquímicos, que a Formação Codó passou por momentos hipersalinos restritos. A presença do gênero Afropollis permite o entendimento das condições de salinidade do meio e a definição do ambiente deposicional.…”

Section: Idadeunclassified

Palinologia Da Formação Codó, Bacia Do Parnaíba: Idade E Paleoambiente Deposicional

ENEAS,

ANTONIOLI,

SOUZA-LIMA

et al. 2023

Geociencias

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Os depósitos siliciclásticos da Formação Codó possuem significativo potencial para geração de hidrocarbonetos no Cretáceo Inferior da Bacia do Parnaíba. Da análise do conteúdo palinológico de 44 amostras do poço 9-PAG-8-MA, foi possível tecer considerações relacionadas ao seu posicionamento temporal e identificar seu paleoambiente deposicional e respectivo paleoclima. Foram identificadas 96 espécies de palinomorfos, predominantemente de origem continental. A presença das espécies-guia Sergipea variverrucata e Equisetosporites maculosus permitiram posicionar bioestratigraficamente os estratos nas palinozonas Sergipea variverrucata (P-270) e Complicatisaccus cearensis (P-280), correspondendo ao neoaptiana. Dinocistos do gênero Subtilisphaera atestam a ocorrência de ingressões marinhas ao longo da sedimentação. Os sedimentos depositaram-se em um ambiente dominantemente continental (flúvio-lacustre), gradando para um ambiente transicional costeiro a marinho restrito, com registros de ingressões marinhas e sob um paleoclima árido a semiárido, evidenciado pelo predomínio de grãos de pólen dos gêneros Classopollis, Gnetaceaepollenites e Equisetosporites. O aumento na frequência relativa dos gêneros Crybelosporites e Cicatricosisporites, observado em dois níveis estratigráficos, sugerem momentos de semiaridez ao longo da deposição, que podem estar relacionadas a redução na salinidade, visto o aumento da frequência relativa de Afropollis e diminuição de Classopollis. O conteúdo palinoflorístico identificado apresenta características que permitem o enquadramento na província palinoflorística a Dicheiropollis etruscus/Afropollis.

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Organic geochemical evidence for the transition of Aptian-Albian hypersaline environments into marine restricted seas: The South Atlantic oceanic northern gateway and its implications for the pre-salt deposits

Cited by 6 publications

References 76 publications

Fossil‐Bearing Concretions of the Araripe Basin Accumulated During Oceanic Anoxic Event 1b

Fossil‐Bearing Concretions of the Araripe Basin Accumulated During Oceanic Anoxic Event 1b

The critical role of accurate fossil identification: the case of the ostracods of the Codó Formation, NE Brazil

Palinologia Da Formação Codó, Bacia Do Parnaíba: Idade E Paleoambiente Deposicional

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