The significance of iron-stained foraminifera off SE Trinidad, West Indies, western central Atlantic Ocean

AbstractEleven samples of seafloor sediment were taken from water depths of 78–90 m within the Savonette Field, off SE Trinidad, western Atlantic Ocean. This surface sediment is relict, having been deposited during an early Holocene transgression. The samples yielded much iron-stained quartz and a rich assemblage of dead foraminifera, of which 75% of planktonic foraminifera were stained with iron, as was 66.5% of the calcareous benthonic foraminiferal assemblage. The fauna, both iron-stained and unstained, was dominated by Cibicidoides ex. gr. pseudoungerianus, and is concluded, despite the proximity of the Orinoco Delta, to be equivalent to a relict Cibicidoides biofacies in carbonate-rich areas of the Gulf of Mexico. Staining was by limonite and hematite. Differing percentages of calcareous benthonic species had been stained with iron, ANOVA revealing three groups of species within which the mean percentage of iron-stained specimens per sample did not differ: (a) Globocassidulina subglobosa and Hanzawaia concentrica; (b) Amphistegina gibbosa, Cassidulina norcrossi australis Cibicioides ex. gr. pseudoungerianus, C. io, Elphidium translucens and Quinqueloculina lamarckiana; and (c) Eponides antillarum and E. repandus. It is concluded that species differ in their susceptibility to iron staining, and that planktonic foraminifera are more susceptible than most benthonic species. Although waters off northern South America are turbid and the photic zone only ~25 m deep, the relict assemblage contained 8.4% algal symbiont-bearing foraminifera (especially A. gibbosa and E. translucens) that would be limited to the photic zone. These are thought to have lived at a time early in the Holocene transgression when sequestration of sediment within the Orinoco delta rendered the water sufficiently clear for viable populations of symbiont-bearing foraminifera. Should iron-stained foraminifera prove to be restricted to transgressive systems tracts, this would make them a useful sequence stratigraphic tool.

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Remarks on the identification of the Albian/Cenomanian boundary and taxonomic clarification of the planktonic foraminifera index speciesglobotruncanoides, brotzeniandtehamaensis

Geological Magazine ◽

10.1017/s0016756814000478 ◽

2014 ◽

Vol 152 (3) ◽

pp. 521-536 ◽

Cited By ~ 15

Author(s):

MARIA ROSE PETRIZZO ◽

MICHÈLE CARON ◽

ISABELLA PREMOLI SILVA

Keyword(s):

Atlantic Ocean ◽

Planktonic Foraminifera ◽

Taxonomic Status ◽

Junior Synonym ◽

Western Atlantic ◽

Western Atlantic Ocean ◽

Unequivocal Identification ◽

Long Time ◽

Stratotype Section ◽

North Western

AbstractThe planktonic foraminifera assemblage across the Global Boundary Stratotype Section and Point (GSSP) for the base of the Cenomanian Stage defined at Mont Risou (Haute-Alpes in France) is here restudied to clarify the identification and stratigraphic distribution ofThalmanninella globotruncanoides( =Rotalipora globotruncanoidesSigal, 1948) andPseudothalmanninella tehamaensis( =Rotalipora tehamaensisMarianos & Zingula, 1966) whose appearance levels are primary and secondary criteria for placing the Albian/Cenomanian boundary. Since the ratification of the GSSP in 2002, the identification of the foraminifera index species across the Albian/Cenomanian boundary has been reported to be sometimes difficult either because of their rarity or uncertainty in the taxonomic identifications. We discuss the taxonomic status ofThalmanninella brotzeniSigal 1948, a species regarded for a long time to be a junior synonym ofTh. globotruncanoides, through images of Sigal's type materials deposited at the Musée National d’Histoire Naturelle (Paris), and elucidate the taxonomically important characters that enable unequivocal identification ofTh. brotzeni, Th. globotruncanoidesandPs. tehamaensis. Planktonic foraminifera marker species from Mont Risou are compared with well-preserved specimens from Blake Nose Plateau (ODP 171B, North Western Atlantic Ocean) to verify the reliability and stratigraphic distribution of these marker taxa outside the Mediterranean Tethyan area.

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Towards a review of the decapod crustacea from the remote oceanic archipelago of Trindade and Martin Vaz, south Atlantic Ocean: new records and notes on ecology and zoogeography

Papéis Avulsos de Zoologia ◽

10.11606/0031-1049.2017.57.14 ◽

2017 ◽

Vol 57 (14) ◽

pp. 157 ◽

Cited By ~ 2

Author(s):

Marcos Domingos Siqueira Tavares ◽

Leina Carvalho ◽

Joel Braga de Mendonça Jr.

Keyword(s):

Atlantic Ocean ◽

New Records ◽

Benthic Fauna ◽

Benthic Invertebrate ◽

Taxonomic Composition ◽

Marine Fauna ◽

Western Atlantic ◽

Comprehensive Knowledge ◽

Insular Endemic ◽

Central Atlantic

The remoteness of the Trindade and Martin Vaz young volcanic archipelago (TMV) raises questions about the source of its marine benthic fauna and levels of endemism. Addressing these questions requires a comprehensive knowledge of the taxonomic composition of the marine fauna of the islands. A five-year survey in the shallow marine waters (up to 30 m) and a literature review on the data published for TMV have been conducted to document the biodiversity of the benthic fauna. Here we report on ten new records of decapod crustaceans from TMV: Gnathophyllum americanum and Thor amboinensis are circumtropical in distribution, whereas Stenopus hispidus, Gnathophylloides mineri and Parribacus antarcticus are disjunct circumtropical species as their distribution in the Atlantic Ocean is limited eastwardly to TMV or Ascension Island (S. hispidus), therefore, do not extending into the eastern Atlantic. Gnathophyllum circellum and Thor manningi are western Atlantic species, with G. circellum previously known only from the Caribbean Sea. Pontonia manningi, Tuleariocaris neglecta and Enoplometopus antillensis are amphi-Atlantic in distribution. Two of the above species are recorded from the southwestern Atlantic for the first time: Gnathophyllum circellum and Tuleariocaris neglecta. These new records corroborate that the marine benthic invertebrate fauna of the TMV archipelago is actually a mosaic of amphi-Atlantic, eastern Atlantic, central Atlantic (insular), endemic and circumtropical species, with a strong western Atlantic component.

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Influence of the Madden–Julian Oscillation and Intraseasonal Waves on Surface Wind and Convection of the Tropical Atlantic Ocean

Journal of Climate ◽

10.1175/jcli-d-11-00528.1 ◽

2012 ◽

Vol 25 (23) ◽

pp. 8057-8074 ◽

Cited By ~ 2

Author(s):

Wei Yu ◽

Weiqing Han ◽

David Gochis

Keyword(s):

Atlantic Ocean ◽

Rossby Waves ◽

Surface Wind ◽

Tropical Atlantic ◽

Madden Julian Oscillation ◽

Monsoon Region ◽

Western Atlantic ◽

African Monsoon ◽

Tropical Atlantic Ocean ◽

Central Atlantic

Abstract Atmospheric intraseasonal variability in the tropical Atlantic is analyzed using satellite winds, outgoing longwave radiation (OLR), and reanalysis products during 2000–08. The analyses focus on assessing the effects of dominant intraseasonal atmospheric convective processes, the Madden–Julian oscillation (MJO), and Rossby waves on surface wind and convection of the tropical Atlantic Ocean and African monsoon area. The results show that contribution from each process varies in different regions. In general, the MJO events dominate the westward-propagating Rossby waves in affecting strong convection in the African monsoon region. The Rossby waves, however, have larger contributions to convection in the western Atlantic Ocean. Both the westward- and eastward-propagating signals contribute approximately equally in the central Atlantic basin. The effects of intraseasonal signals have evident seasonality. Both convection amplitude and the number of strong convective events associated with the MJO are larger during November–April than during May–October in all regions. Convection associated with Rossby wave events is stronger during November–April for all regions, and the numbers of Rossby wave events are higher during November–April than during May–October in the African monsoon region, and are comparable for the two seasons in the western and central Atlantic basins. Of particular interest is that the MJOs originating from the Indo-Pacific Ocean can be enhanced over the tropical Atlantic Ocean while they propagate eastward, amplifying their impacts on the African monsoon. On the other hand, Rossby waves can originate either in the eastern equatorial Atlantic or West African monsoon region, and some can strengthen while they propagate westward, affecting surface winds and convection in the western Atlantic and Central American regions.

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PRIMER HALLAZGO DE APIOMITHRAX VIOLACEUS (A. MILNE-EDWARDS) (BRACHYURA: EPIALTIDAE: PISINAE) PARA EL CARIBE

Bulletin of Marine and Coastal Research ◽

10.25268/bimc.invemar.2010.39.2.157 ◽

2016 ◽

Vol 39 (2) ◽

Author(s):

Carlos Lira ◽

Juan Bolaños ◽

Gonzalo Hernández ◽

Jesús Hernández ◽

Régulo López

Keyword(s):

Caribbean Sea ◽

Western Atlantic ◽

Orinoco Delta ◽

Ascension Island ◽

The Caribbean ◽

Central Atlantic ◽

First Time

Up to now, the sub-family Pisinae Dana, 1851 was represented in the Caribbean coasts of Venezuela by six species [Chorinus heros (Herbst, 1790); Libinia ferreirae Brito Capello, 1871; Herbstia depressa Stimpson, 1870; Sphenocarcinus corrosus A. Milne-Edwards, 1878; Pelia mutica (Gibbes, 1850) and Nibilia antilocapra (Stimpson, 1871)], which make up 38 % of the Pisinae crabs reported for the Caribbean Sea. During an examination of unidentified material from the crustacean collection of the Laboratory of Carcinology at Universidad de Oriente, Margarita Island, Venezuela, nine specimens (six males and three females) of Apiomithrax violaceus (A. Milne-Edwards, 1868) were discovered. Until now the distribution of this Pisinae species was known to range from Mauritania to Angola in the eastern Atlantic, Ascension Island in the central Atlantic, as well as Brazil and Orinoco Delta in the western Atlantic. All specimens were collected in Venezuelan waters, at the following locations: Margarita island: Playa Valdés, Península de Macanao, Boca Chica, El Maguey; Sucre State (mainland): Guayacán. This is the most northerly record of the species and it is the first time to be reported for the Caribbean Sea, increasing the number of known species of Pisinae to 17 in this area.

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Disruption of the Atlantic Meridional Circulation during Deglacial Climates Inferred from Planktonic Foraminiferal Shell Weights

Journal of Marine Science and Engineering ◽

10.3390/jmse9050519 ◽

2021 ◽

Vol 9 (5) ◽

pp. 519

Author(s):

Stergios D. Zarkogiannis

Keyword(s):

Atlantic Ocean ◽

Meridional Circulation ◽

Order Approximation ◽

Planktonic Foraminifera ◽

Sediment Cores ◽

Meridional Overturning Circulation ◽

Density Structure ◽

Last Interglacial ◽

Shell Weight ◽

The North

Changes in the density structure of the upper oceanic water masses are an important forcing of changes in the Atlantic Meridional Overturning Circulation (AMOC), which is believed to widely affect Earth’s climate. However, very little is known about past changes in the density structure of the Atlantic Ocean, despite being extensively studied. The physical controls on planktonic foraminifera calcification are explored here, to obtain a first-order approximation of the horizontal density gradient in the eastern Atlantic during the last 200,000 years. Published records of Globigerina bulloides shells from the North and Tropical eastern Atlantic were complemented by the analysis of a South Atlantic core. The masses of the same species shells from three different dissolution assessed sediment cores along the eastern Atlantic Ocean were converted to seawater density values using a calibration equation. Foraminifera, as planktonic organisms, are subject to the physical properties of the seawater and thus their shells are sensitive to buoyancy forcing through surface temperature and salinity perturbations. By using planktonic foraminifera shell weight as an upper ocean density proxy, two intervals of convergence of the shell masses are identified during cold intervals of the last two deglaciations that may be interpreted as weak ocean density gradients, indicating nearly or completely eliminated meridional circulation, while interhemispheric Atlantic density differences appear to alleviate with the onset of the last interglacial. The results confirm the significance of variations in the density of Atlantic surface waters for meridional circulation changes.

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The wet deposition of trace metals to the western atlantic ocean at the mid-atlantic coast and on Bermuda

Atmospheric Environment (1967) ◽

10.1016/0004-6981(84)90330-5 ◽

1984 ◽

Vol 18 (12) ◽

pp. 2657-2664 ◽

Cited By ~ 95

Author(s):

T.M. Churc ◽

J.M. Tramontano ◽

J.R. Scudlark ◽

T.D. Jickells ◽

J.J. Tokos ◽

...

Keyword(s):

Trace Metals ◽

Atlantic Ocean ◽

Wet Deposition ◽

Atlantic Coast ◽

Western Atlantic ◽

Western Atlantic Ocean

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The Upper Cretaceous foraminiferal record of IODP Site U1512 (Great Australian Bight, Indian Ocean)

10.5194/egusphere-egu21-7844 ◽

2021 ◽

Author(s):

Erik Wolfgring ◽

Michael A. Kaminski ◽

Anna Waśkowska ◽

Maria Rose Petrizzo ◽

Eun Young Lee ◽

...

Keyword(s):

Indian Ocean ◽

Ocean Circulation ◽

Planktonic Foraminifera ◽

Late Eocene ◽

Foraminiferal Assemblage ◽

Benthic Foraminiferal Assemblage ◽

International Ocean Discovery Program ◽

Foraminiferal Record ◽

Great Australian Bight ◽

Microfossil Assemblage

Site U1512 was drilled during Expedition 369 of the International Ocean Discovery Program (IODP), which is located in the Great Australian Bight, southern Indian Ocean. It provides exceptional insights into the benthic foraminiferal biostratigraphy and paleoecology of a high southern latitude restricted marginal marine basin during the Late Cretaceous hot greenhouse climate and the rifting between Australia and Antarctica. The sedimentary sequence recovered at Site U1512 presents a rare record of a deep water agglutinated foraminifera (DWAF) community from the Southern High Latitudes. The Cretaceous record at Site U1512 covers the lower Turonian through Santonian (nannofossil zones UC8b to UC12/CC10b to CC16, H. helvetica to Marginotruncana spp. - Planoheterohelix papula - Globotruncana linneana planktonic foraminifera zones). Diverse benthic foraminiferal assemblages yield many new taxa that are yet to be described.Agglutinated forms dominate the assemblage in most intervals. In lower to mid Turonian and Santonian strata, calcareous benthic as well as planktonic foraminifera are frequent. Abundant radiolaria are recovered from the mid Turonian, and they increase up-section and exceed 50% of the microfossil assemblage. We documented a diverse benthic foraminiferal assemblage consisting of 162 taxa (110 agglutinated and 52 calcareous). The most common taxa of the DWAF assemblage are tubular (i.e., Kalamopsis grzybowskii, Bathysiphon spp.) and planispiral forms (i.e., Ammodiscus spp., Haplophragmoides spp., Buzasina sp., Labrospira spp.).The Turonian strata yield highly abundant Bulbobaculites problematicus and Spiroplectammina navarroana. The presence of the agglutinated foraminiferal marker taxa Uvigerinammina jankoi and Bulbobaculites problematicus provides a tie-point to the Tethyan DWAF biozonation of Geroch and Nowak (1984). The composition of foraminiferal assemblages and the increase in radiolaria abundance suggest unstable environmental conditions at Site U1512 during the early Turonian through Santonian. These characteristics refer to changes in bathymetry associated with changing ocean chemistry. Results of quantitative analyses of the benthic foraminiferal assemblages indicate a restricted paleoenvironmental regime, dictated by changes in paleobathymetry, unstable patterns in ocean circulation, and the discharge of a nearby river delta system.References: Geroch, S., Nowak, K., 1984. Proposal of zonation for the Late Tithonian &#8211; late Eocene. based upon arenaceous Foraminifera from the Outer Carpathians, Poland, 225-239, In: Oertli, H.J. (Ed.), Benthos &#180;83; 2nd international 915 Symposium on Benthic Foraminifera, Pau (France) April 11-15, 1983, Elf Aquitaine, ESO REP and TOTAL CFP, Pau and Bordeaux.&#160;

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