Late Cretaceous to early Quaternary organic sedimentation in the eastern Equatorial Atlantic

Wagner, Thomas

doi:10.1016/s0031-0182(01)00415-1

Cited by 74 publications

(91 citation statements)

References 125 publications

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“…Qualitative analysis of sediments in the estuary highlighted its slow siltation as designed in its realization. Indeed, it was noted an almost non mixing marine sediments (mainly sand Marine 50 Quaternary (sandy texture of very rough and coarse) (Wagner, 2002)) to the station S1 with lagoon sediments (coarse sand and silt from meteorites contributions, wastewater discharges, organic matter from detritus terrigenous particles and/or plant debris) to stations S2 and S3. Due to its orientation, the contribution of marine sediments from Atlantic Ocean are most hampered by the canyon and finally stopped by discarded and wing walls just after the station S1; while those from continental will first settle in the lagoon area of the harbor and later stopped (mostly in the form of coarse and medium sands) by discarded and wing walls at the station S2.…”

Section: Resultsmentioning

confidence: 99%

Metal Pollution and Ecological Risk Assessment in Sediment of Artificial Estuary: Case of Vridi Channel, Côte d’Ivoire

Yao¹,

Brou²,

Trokourey³

et al. 2017

Journal of Applied Sciences and Environmental Management

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This study focused on a yearly monitoring of sediment pollution in Cd, Co, Cu, Fe, Mg, Mn, Ni, Pb, Zn and the ecological incurred risks in Vridi channel. The results, expressed per dry weight, showed that the annual mean were 0.96 (± 0.16) mg/Kg for Cd, 22.36 (± 2.41) mg/kg for Co, 33.98 (± 4.61) for Cu, 31760.5 (± 5652.7) mg/kg for Fe, 981.2 ± (377.5) mg/kg for Mg, 302.9 (± 415.4) mg/kg for Mn, 42.53 (± 9.79) mg/kg for Ni, 83.37 (± 6.66) mg/kg for Pb and 27.11 (± 11.72) mg/kg for Zn. The measured oligo-elements (Fe, Mn, Mg, Zn) originated from naturals sources and were away from accumulation, except from Fe which moderately accumulated. That hence the low sediment contamination by these metals. As for toxic trace metal (not essential) to living organisms (Co, Cu, Pb, Cd, Ni), they resulted from anthropogenic origin. These sediments were moderately contaminated in Co, Cu and Ni, significantly in Pb and strongly in Cd. All the studied trace metals were mainly from continental origin, except Cd which showed a marine origin. This estuary displayed a steady state of progressive deterioration and presented a very high ecological risk. © JASEM https://dx.doi.org/10.4314/jasem.v21i4.20

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Section: Resultsmentioning

confidence: 99%

Metal Pollution and Ecological Risk Assessment in Sediment of Artificial Estuary: Case of Vridi Channel, Côte d’Ivoire

Yao¹,

Brou²,

Trokourey³

et al. 2017

Journal of Applied Sciences and Environmental Management

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“…Thus, the cause of organic-rich sedimentation in the Atlantic during a time of worldwide oxic deepwater sedimentation is not a consequence of a global warming event, but organic-rich sedimentation during ConiacianSantonian must have been driven by the special configuration of the Atlantic Ocean and the surrounding shelf basins and continents. Wagner (2002) and Hofmann et al (2003) suggested a strong link of these black shales to wind-driven upwelling of nutrient-rich intermediate seawater, probably related to an estuarine circulation with respect to the Pacific from where nutrient-rich seawater derived, and the lowlatitudinal Atlantic served as a nutrient trap for a prolonged time interval (Trabucho Alexandre et al, 2010). Beckmann et al (2005b) and Flögel et al (2008) furthermore invoked millennial-to centennial-scale climate variability, i.e.…”

Section: Discussionmentioning

confidence: 97%

“…In principle, windinduced upwelling of nutrient-rich water masses was involved to explain high productivity, and subsequent deposition and preservation of organic-carbon-rich sediments at ODP site 959 (e.g. Wagner, 2002;Hofmann and Wagner, 2011). Increased oxygen consumption from the degradation of organic matter resulted in expansion of the oxygen minimum zone and stratification of the water column which controlled organic-carbon-rich deposition .…”

Section: Mechanisms and Modelsmentioning

confidence: 99%

“…ODP Leg 159 (Wagner, 2002;Hofmann et al, 2003;Jones et al, 2007) and the Demerara Rise, ODP Leg 207 (e.g. Friedrich and Erbacher, 2006;Beckmann et al, 2008), the Caribbean, and connected marginal and epeiric seas and seaways such as the Western Interior (Locklair et al, 2011), the Maracaibo Basin (Rey et al, 2004) and basins of northwestern Africa (El Albani et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

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"OAE 3" – regional Atlantic organic carbon burial during the Coniacian–Santonian

Wagreich

2012

Clim. Past

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Abstract. The Coniacian-Santonian time interval is the inferred time of oceanic anoxic event 3 (OAE 3), the last of the Cretaceous OAEs. A detailed look on the temporal and spatial distribution of organic-rich deposits attributed to OAE 3 suggests that black shale occurrences are restricted to the equatorial to mid-latitudinal Atlantic and adjacent basins, shelves and epicontinental seas like parts of the Caribbean, the Maracaibo Basin and the Western Interior Basin, and are largely absent in the Tethys, the North Atlantic, the southern South Atlantic, and the Pacific. Here, oxic bottom waters prevailed as indicated by the widespread occurrence of red deep-marine CORBs (Cretaceous Oceanic Red Beds). Widespread CORB sedimentation started during the Turonian after Oceanic Anoxic Event 2 (OAE 2) except in the Atlantic realm where organic-rich strata continue up to the Santonian. The temporal distribution of black shales attributed to OAE 3 indicates that organic-rich strata do not define a single and distinct short-time event, but are distributed over a longer time span and occur in different basins during different times. This suggests intermittent and regional anoxic conditions from the Coniacian to the Santonian. A comparison of time-correlated high-resolution δ 13 C curves for this interval indicates several minor positive excursions of up to 0.5 ‰, probably as a result of massive organic carbon burial cycles in the Atlantic. Regional wind-induced upwelling and restricted deep basins may have contributed to the development of anoxia during a time interval of widespread oxic conditions, thus highlighting the regional character of inferred OAE 3 as regional Atlantic event(s).

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“…Major climatic changes occurred in sub-Saharan Africa during the Pleistocene. Th e period of climatic instability started 3.3 to 2.45 Ma, oscillating between hot/humid and cooler, drier periods (Wagner 2002). A shift to arid, open conditions occurred in near 2.8 Ma, 1.7 Ma, and 1.0 Ma ( de Menocal 1995).…”

Section: Busseola Fuscamentioning

confidence: 99%

Phylogeographic pattern and regional evolutionary history of the maize stalk borerBusseola fusca(Fuller) (Lepidoptera: Noctuidae) in sub-Saharan Africa

Sezonlin¹,

Dupas²,

Rü

et al. 2006

Annales de la Société entomologique de France (N.S.)

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Abstract. Busseola fusca (Fuller) (Lepidoptera: Noctuidae) is one of the major cereal pests in subSaharan Africa. Previous phylogeographic investigations on samples collected in Kenya, Cameroon and West-Africa showed the presence of three main clades (W, KI, KII) originated from populations isolated in West and East Africa around one million years ago. Demographic and phylogenetic analyses suggested that this event was followed by local demographic expansion and isolation by distance. These hypotheses were tested by a more comprehensive sampling across B. fusca's geographic range in Africa. Comparisons of sequences of partial mitochondrial DNA gene (cytochrome b) from 489 individuals of 98 localities in southern, central, eastern and western African countries confi rmed the presence of the three main clades. Phylogenetic, F-statistics, demographic parameters and nested clade phylogeographic analyses confi rmed that the clades experienced geographic and demographic expansion with isolation by distance after their isolation in three refuge areas. The geographic range of clade KII, already known from East to Central sub-Saharan Africa was extended to Southern Africa. Mismatch distribution analysis and the negative values of Tajima's D index are consistent with a demographic expansion hypothesis for these three clades. Signifi cant genetic differentiations were revealed at various hierarchical levels by analysis of molecular variance (AMOVA). Hypotheses about the geographic origin of the three main clades are detailed. Résumé. Scénario phylogéographique et histoire évolutive régionale du foreur de graminéesBusseola fusca (Fuller) (Lepidoptera : Noctuidae) en Afrique sub-saharienne. Busseola fusca (Fuller) (Lépidoptère : Noctuidae) est l'un des ravageurs majeurs des cultures céréalières en Afrique Subsaharienne. Une première étude phylogéographique portant sur des individus échantillonnés au Kenya, au Cameroun et en Afrique de l'Ouest a montré l'existence de trois clades principaux (W, KI, KII) issus de populations isolées à l'Ouest et à l'Est de l'Afrique il y a environ un million d'années. Les analyses démographiques et phylogénétiques indiquent que cet événement a été suivi d'une expansion démographique locale avec des phénomènes d'isolement par la distance. Ces hypothèses ont été testées à plus grande échelle grâce à un échantillonnage des populations de B. fusca couvrant désormais la majeure partie de son aire de distribution. Le séquençage d'un fragment du gène mitochondrial codant pour le cytochrome b chez 489 individus provenant de 98 localités des pays sud, centre, est et ouest africains confi rme l'existence des trois clades observés précédemment. Les résultats des analyses phylogénétiques, les paramètres démographiques, les statistiques de Wright ainsi que les analyses des clades emboîtés confi rment que ces trois populations, après avoir été isolées dans des aires refuges différentes, ont connu une expansion démographique et géographique avec un isolement par la distance. La distribution géographique du c...

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Late Cretaceous to early Quaternary organic sedimentation in the eastern Equatorial Atlantic

Cited by 74 publications

References 125 publications

Metal Pollution and Ecological Risk Assessment in Sediment of Artificial Estuary: Case of Vridi Channel, Côte d’Ivoire

Metal Pollution and Ecological Risk Assessment in Sediment of Artificial Estuary: Case of Vridi Channel, Côte d’Ivoire

"OAE 3" – regional Atlantic organic carbon burial during the Coniacian–Santonian

Phylogeographic pattern and regional evolutionary history of the maize stalk borerBusseola fusca(Fuller) (Lepidoptera: Noctuidae) in sub-Saharan Africa

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Late Cretaceous to early Quaternary organic sedimentation in the eastern Equatorial Atlantic

Cited by 74 publications

References 125 publications

Metal Pollution and Ecological Risk Assessment in Sediment of Artificial Estuary: Case of Vridi Channel, Côte d’Ivoire

Metal Pollution and Ecological Risk Assessment in Sediment of Artificial Estuary: Case of Vridi Channel, Côte d’Ivoire

&quot;OAE 3&quot; – regional Atlantic organic carbon burial during the Coniacian–Santonian

Phylogeographic pattern and regional evolutionary history of the maize stalk borerBusseola fusca(Fuller) (Lepidoptera: Noctuidae) in sub-Saharan Africa

Contact Info

Product

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"OAE 3" – regional Atlantic organic carbon burial during the Coniacian–Santonian