Palynofacies analysis of sediments from the Côte d'Ivoire-Ghana transform margin: Preliminary correlation with some regional events in the Equatorial Atlantic

Oboh‐Ikuenobe, Francisca E.; Yepes, Oscar

doi:10.1016/s0031-0182(96)00125-3

Cited by 52 publications

(26 citation statements)

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“…Second, it could be due to postdepositional carbonate dissolution through PETM ocean acidification as recorded in deep ocean basins . However, at no single site described so far, did the carbonate compensation depth (CCD) rise above the reconstructed paleodepth (∼ 1000 m, Oboh-Ikuenobe et al, 1997) for this site; thus, this scenario seems unlikely. Third, carbonates can be dissolved locally through enhanced oxic organic matter decomposition at the sea floor, producing CO 2 .…”

Section: Absolute Temperature and Temperature Change In A Global Persmentioning

confidence: 88%

“…1). From the Early Cretaceous onwards, the submarine high has been subsiding, reaching bathyal depths around the CretaceousPaleogene boundary (Oboh-Ikuenobe et al, 1997); the present-day water depth is ∼ 2000 m (Shipboard Scientific Party, 1996). Calcareous nannofossil biostratigraphy indicates the presence of the upper Paleocene CP8a-CP8b zone boundary in the interval from core section 41R-6 to core section 42R-2 (Shafik et al, 1998).…”

Section: Methodsmentioning

confidence: 99%

“…Lower calcium carbonate accumulation at Sites 1209, 1220, and 1221 has been explained by dissolution. Also, the absence of calcium carbonate at sites in the Caribbean and western equatorial Atlantic (ODP Sites 999, 1001, 1258, and 1260) has been attributed to carbonate dissolution Mutterlose et al, 2007). Importantly, however, an influence of heat stress on carbonate production cannot be excluded.…”

Section: Global Tropical Heat Stress?mentioning

confidence: 99%

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Tropical Atlantic climate and ecosystem regime shifts during the Paleocene–Eocene Thermal Maximum

et al. 2018

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Abstract. The Paleocene-Eocene Thermal Maximum (PETM, 56 Ma) was a phase of rapid global warming associated with massive carbon input into the ocean-atmosphere system from a 13 C-depleted reservoir. Many midlatitude and high-latitude sections have been studied and document changes in salinity, hydrology and sedimentation, deoxygenation, biotic overturning, and migrations, but detailed records from tropical regions are lacking. Here, we study the PETM at Ocean Drilling Program (ODP) Site 959 in the equatorial Atlantic using a range of organic and inorganic proxies and couple these with dinoflagellate cyst (dinocyst) assemblage analysis. The PETM at Site 959 was previously found to be marked by a ∼ 3.8 ‰ negative carbon isotope excursion (CIE) and a ∼ 4 • C surface ocean warming from the uppermost Paleocene to peak PETM, of which ∼ 1 • C occurs before the onset of the CIE. We record upper Paleocene dinocyst assemblages that are similar to PETM assemblages as found in extratropical regions, confirming poleward migrations of ecosystems during the PETM. The early stages of the PETM are marked by a typical acme of the tropical genus Apectodinium, which reaches abundances of up to 95 %. Subsequently, dinocyst abundances diminish greatly, as do carbonate and pyritized silicate microfossils. The combined paleoenvironmental information from Site 959 and a close-by shelf site in Nigeria implies the general absence of eukaryotic surface-dwelling microplankton during peak PETM warmth in the eastern equatorial Atlantic, most likely caused by heat stress. We hypothesize, based on a literature survey, that heat stress might have reduced calcification in more tropical regions, potentially contributing to reduced deep sea carbonate accumulation rates, and, by buffering acidification, also to biological carbonate compensation of the injected carbon during the PETM. Crucially, abundant organic benthic foraminiferal linings imply sustained export production, likely driven by prokaryotes. In sharp contrast, the recovery of the CIE yields rapid ( 10 kyr) fluctuations in the abundance of several dinocyst groups, suggesting extreme ecosystem and environmental variability.

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Section: Absolute Temperature and Temperature Change In A Global Persmentioning

confidence: 88%

Section: Methodsmentioning

confidence: 99%

Section: Global Tropical Heat Stress?mentioning

confidence: 99%

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Tropical Atlantic climate and ecosystem regime shifts during the Paleocene–Eocene Thermal Maximum

et al. 2018

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“…Palynofacies analysis is commonly used to assess depositional environments (e.g., Parry et al 1981;Boulter and Riddick 1986;Van der Zwan 1990;Brugman et al 1994;Oboh-Ikuenobe and Yepes 1997;Oboh-Ikuenobe et al 2005;Carvalho et al 2006). In this study, palynofacies analysis attempts to provide a more in depth interpretation of the depositional environments at Hasty Bank.…”

Section: Methodsmentioning

confidence: 99%

A quantitative comparison of dispersed spore/pollen and plant megafossil assemblages from a Middle Jurassic plant bed from Yorkshire, UK

Slater

Wellman

2015

Paleobiology

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Abstract.-Detailed quantitative data has previously been collected from plant megafossil assemblages from a Middle Jurassic (Aalenian) plant bed from Hasty Bank, North Yorkshire, UK. We conducted a similar analysis of palynological dispersed sporomorph (spore and pollen) assemblages collected from the same section using the same sampling regime: 67 sporomorph taxa were recorded from 50 samples taken at 10 cm intervals through the plant bed. Basic palynofacies analysis was also undertaken on each sample. Both dispersed sporomorph and plant megafossil assemblages display consistent changes in composition, diversity (richness), and abundance through time. However, the dispersed sporomorph and plant megafossil records provide conflicting evidence for the nature of parent vegetation. Specifically, conifers and ferns are underrepresented in plant megafossil assemblages, bryophytes and lycopsids are represented only in sporomorph assemblages, and sphenophytes, pteridosperms, Caytoniales, Cycadales, Ginkgoales and Bennettitales are comparatively underrepresented in sporomorph assemblages. Combined multivariate analysis (correspondence analysis and nonmetric multidimensional scaling) of sporomorph occurrence/abundance data demonstrates that temporal variation in sporomorph assemblages is the result of depositional change through the plant bed. The reproductive strategies of parent plants are considered to be a principal factor in shaping many of the major abundance and diversity irregularities between dispersed sporomorph and plant megafossil data sets that seemingly reflects different parent vegetation. Preferential occurrence/preservation of sporomorphs and equivalent parent plants is a consequence of a complex array of biological, ecological, geographical, taphonomic, and depositional factors that act inconsistently between and within fossil assemblages, which results in notable discrepancies between data sets.

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“…Boulter y Riddick, 1986;Van Bergen et al, 1990;Tyson, 1995;Batten, 1996;Oboh-Ikuenobe et al, 1997). En este estudio se utiliza un sistema simplificado adaptado a los tipos de componentes orgánicos presentes, basado en una terminología adaptada de Van Bergen et al (1990), Batten (1996) y Oboh-Ikuenobe et al (1997,2005).…”

Section: Identificación Del Materials Palinológicounclassified

El sistema lacustre de la Formación Mollar en el depocentro triásico de Santa Clara (provincia de Mendoza, Argentina)

Spalletti

Zavattieri²

2009

AndGeo

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RESUMEN. El depocentro triásico de Santa Clara, Cuenca Cuyana, se caracteriza por espesos depósitos generados en ambiente lacustre. Uno de ellos, con un registro de más de 345 m, corresponde a la Formación Mollar. El tramo inferior a medio está caracterizado por una monótona sucesión de lutitas bituminosas acumuladas por decantación suspensiva en el 'offshore' anóxico de un cuerpo lacustre hidrológicamente cerrado y que muestra alto contenido de materia orgánica amorfa de origen algal y de restos de plantas terrestres muy degradadas junto a sulfuros de hierro autígenos. Intercalan areniscas finas debidas a corrientes de turbidez diluidas y carbonatos estromatolíticos. En esta sucesión se definen ciclos granocrecientes de pequeña escala (PACs) que se atribuyen a episodios de expansión-retracción lacustre controlados por cambios climáticos. Asociaciones de facies heterolíticas representan los depósitos de la transición entre los ambientes de 'nearshore' y 'offshore' lacustre. La sección superior de la Formación Mollar se compone de sucesiones pelíticas con profusa bioturbación que sugieren mayor oxigenación del sustrato y se asignan a ambiente de costa afuera de un sistema lacustre holomíctico hidrológicamente abierto. Intercalan areniscas producto de flujos hiperpicnales. Depósitos de areniscas con abundantes trazas fósiles y estructuras de olas y flujos unidireccionales, representan a sectores marginales del ambiente lacustre. Además de los ciclos de alta frecuencia, en la Formación Mollar se definen tres secuencias asimétricas de mayor escala atribuidas a episodios mayores de expansión-contracción lacustre debidos a la interacción entre factores climáticos y tectónicos. El diseño de superposición granocreciente de la Formación Mollar y la gradual transición a depósitos fluviales de la sobreyacente Formación Montaña refleja asimismo una constante reducción del espacio de acomodación sedimentaria en el depocentro de Santa Clara a medida que se produjo la acumulación de los depósitos estudiados.

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Palynofacies analysis of sediments from the Côte d'Ivoire-Ghana transform margin: Preliminary correlation with some regional events in the Equatorial Atlantic

Cited by 52 publications

References 12 publications

Tropical Atlantic climate and ecosystem regime shifts during the Paleocene–Eocene Thermal Maximum

Tropical Atlantic climate and ecosystem regime shifts during the Paleocene–Eocene Thermal Maximum

A quantitative comparison of dispersed spore/pollen and plant megafossil assemblages from a Middle Jurassic plant bed from Yorkshire, UK

El sistema lacustre de la Formación Mollar en el depocentro triásico de Santa Clara (provincia de Mendoza, Argentina)

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