Seismic stratigraphy and biostratigraphic context of coquina progradations in Mero field and their impact on the paleocirculation of the South Atlantic Proto-ocean
DOI:
https://doi.org/10.70369/y6te4086Keywords:
Seismic stratigraphy, Itapema Formation, Paleocirculation, South Atlantic OceanAbstract
During the Libra block exploration phase from 2013 to 2018, delimitation wells were drilled, and frequently reprocessed seismic data were utilized to support this study. Due to the challenges in tracking and predicting the upper boundary of the Itapema Formation at the Libra block, each new set of seismic data was remapped. This process was essential for gaining a clearer understanding of the stratigraphy and distribution of the coquina interval. The Coquina deposits can be divided into two primary progradational domains, each one exhibiting distinct seismic characteristics in terms of seismic facies. Biostratigraphic data obtained from exploratory wells drilled during this phase were used to enhance the correlation of the seismic sequences identified in previous mappings. This correlation, along with the well results, validated the adopted mapping method. The interval analysis revealed various stratigraphic arrangements of coquina deposits across the northwestern structure of Mero. The geometries of these deposits, along with their biostratigraphic associations, suggest the presence of older coquinas (NRT-009.3, NRT- 009.1 and NRT-008.1) in the higher structural areas to the south of the northwest sector of Mero, while younger coquinas (OS-1020) are found in the central part of the northwest sector. This verification of the association closely links the coquina deposits to the paleoenvironmental changes that occurred during the rifting process, which ultimately led to the opening of the South Atlantic Ocean. The orientation of the observed clinoforms indicates a shift in the dynamics of surface and bottom currents during the Jiquiá period, which may reflect variations in the base level of the system or the interplay of both processes. Additionally, the mapping played a crucial role in distinguishing the internal horizons within the Itapema Formation. This study thus enhanced our understanding of the evolution of various environmental scenarios that locally led to a remarkable stacking of over 500 meters of shell deposits, arranged in a distinctive stratigraphic configuration observed in nature.
References
Borges, T.A., e Gamboa, L.A.P., 2015, Sismo-estratigrafia do limite sul da Bacia de Santos e suas implicações na evolução do Atlântico sul primordial: Rio de Janeiro: Boletim de Geociências da Petrobras, v. 23, n. 1-2, p. 177- 204.
Borges, T.A., Paula L., e Gamboa, L.A.P., 2013, Seismic stratigraphy analysis of south Santos Basin and its implications on the early South Atlantic evolution, in Martinelli, J.C., ed., International Congress of the Brazilian Geophysical Society & EXPOGEF, 13th, Brazil: Rio de Janeiro: Society of Exploration Geophysicists and Brazilian Geophysical Society, p. 627-634.
Borgomano, J., Lanteaume, C., Léonide, P., Fournier, F., Montaggioni, L.F., e Masse, J., 2020, Quantitative carbonate sequence stratigraphy: Insights from stratigraphic forward models: AAPG Bulletin, v. 104, n. 5, p. 1115-1142, doi: http://dx.doi.org/10.1306/11111917396.
Carlotto, M.A., et al., 2017, Libra: A newborn giant in the Brazilian presalt Province, in R. K. Errill and C. A. Sternbach., eds., Giant fields of the decade 2000–2010: AAPG Memoir, v. 113, p. 165- 176, doi: https://doi.org/10.1306/13572006M1133685.
MacEachern, J. A., Dashtgard, S.E., Knaust, D., Catuneanu, O., Bann, K.L., e Pemberton, S.G., 2022, Sequence stratigraphy: Developments in Sedimentology, v. 64, p. 157-194, doi: https://doi.org/10.1016/B978-0-444-53813-0.00006-X.
Mitchum Jr, R.M., e Vail, P.R., 1977, Seismic stratigraphy and global changes of sea level: Part 7. Seismic stratigraphic interpretation procedure: Section 2. Application of seismic reflection configuration to stratigraphic interpretation, in Seismic Stratigraphy-Applications to Hydrocarbon Exploration, p. 135-143.
Moreira, J.L.P., Madeira, C.V., Gil, J.A., e Machado, M.A.P., 2007, Bacia de Santos: Boletim de Geociências da Petrobras, v. 15, n. 2, p. 531–550.
Neuharth, Derek et al., 2021, Formation of continental microplates through rift linkage: Numerical modeling and its application to the Flemish Cap and Sao Paulo Plateau: Geochemistry, Geophysics, Geosystems, v. 22, n. 4, doi: https://doi.org/10.1029/2020GC009615.
Oliveira, L.C., Borges T.A., e Moreira, J.L.P., 2015, Características sísmicas e distribuição de feições ígneas intrusivas e extrusivas no Santoniano/Campaniano, norte da Bacia de Santos, In X Congresso Internacional de Vulcanismo e ambientes associados. São Paulo, USP.
Qayyum, F., Catuneanu, O., e Bouanga, C.E., 2015, Sequence stratigraphy of a mixed siliciclastic-carbonate setting, Scotian Shelf, Canada: Interpretation, v. 3, n. 2, p. SN21- SN37, doi: https://doi.org/10.1190/INT-2014-0129.1.
Sarg, J.F., 1988, Carbonate sequence stratigraphy: Special Publications of SEPM, n. 42.
Schaller, H., 1969, Revisão estratigráfica da bacia de Sergipe- Alagoas: Boletim Técnico da Petrobras, v. 12, n. 1, p. 21-86.
Silva-Telles Jr., A.C., 1992, Novo zoneamento da sequência das coquinas da Formação Lagoa Feia (Neo-Jiquiá da bacia de Campos) com base em ostracodes-aspectos evolutivos, In 37°Congresso Brasileiro de Geologia-SBG, São Paulo: Boletim de Resumos Expandidos, p. 489-490.
Wheeler, H.E., 1958, Time-stratigraphy: AAPG Bulletin, n. 42, v. 5, p. 1047-1063, doi: https://doi.org/10.1306/0BDA5AF2-16BD-11D7-8645000102C1865D.
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