Mineralogy and chemical composition of ferromanganese crusts from the Cruzeiro do Sul Lineament - Rio Grande Rise, South Atlantic

A taxonomic revision of the Nystiellidae from Brazil, including samples from the Rio Grande Rise, South Atlantic, was performed based on shell morphology. Five genera and 17 species were recognized. For the richest genus,Eccliseogyra, the three species previously recorded from Brazil were revised:E. brasiliensisandE. maracatu, previously known only from their respective type series, were re-examined. Newly available material ofE. maracatuexpanded the known geographic range of this species to off south-east Brazil.Eccliseogyra nitidais now recorded from north-eastern to south-eastern Brazil, as well as from the Rio Grande Rise. Three species ofEccliseogyraare newly recorded from the South Atlantic:E. monnioti, previously known from the north-eastern Atlantic, occurs off eastern Brazil and on the Rio Grande Rise; its protoconch is described for the first time, confirming its family allocation.Eccliseogyra pyrrhiasoccurs off eastern Brazil and on the Rio Grande Rise, andE. folinioff eastern Brazil. The genusIphitusis newly recorded from the South Atlantic.Iphitus robertsiwas found off northern Brazil, although the shells show some differences from the type material, with less-pronounced spiral keels. Additional new finds showed thatIphitus cancellatusranges from eastern Brazil to the Rio Grande Rise, and Iphitusnotiossp. nov. is restricted to the Rio Grande Rise.Narrimania, previously recorded from Brazil based on dubious records, is confirmed, including the only two living species described for the genus:N. azelotes, previously only known from the type locality in Florida, andN. concinna, previously known from the Mediterranean. A third species,Narrimania raquelaesp. nov. is described from eastern Brazil, diagnosed by its numerous and thinner cancellate sculpture. To the three species ofOpaliopsispreviously known from Brazil, a fourth species,O. arnaldoisp. nov., is added from eastern Brazil, and diagnosed by its very thin spiral sculpture, absence of a varix, and thinner microscopic parallel axial striae.Papuliscala nordestina, originally described from north-east Brazil, is recorded off eastern Brazil and synonymized withP. elongata, a species previously known only from the North Atlantic.

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Geochemical insights into formation of enigmatic ironstones from Rio Grande rise, South Atlantic Ocean

Marine Geology ◽

10.1016/j.margeo.2021.106716 ◽

2021 ◽

pp. 106716

Author(s):

Mariana Benites ◽

James R. Hein ◽

Kira Mizell ◽

Kenneth A. Farley ◽

Jonathan Treffkorn ◽

...

Keyword(s):

Atlantic Ocean ◽

Rio Grande ◽

South Atlantic ◽

South Atlantic Ocean

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Mineral Phase-Element Associations Based on Sequential Leaching of Ferromanganese Crusts, Amerasia Basin Arctic Ocean

Minerals ◽

10.3390/min8100460 ◽

2018 ◽

Vol 8 (10) ◽

pp. 460 ◽

Cited By ~ 5

Author(s):

Natalia Konstantinova ◽

James Hein ◽

Amy Gartman ◽

Kira Mizell ◽

Pedro Barrulas ◽

...

Keyword(s):

Chemical Composition ◽

Arctic Ocean ◽

The Arctic ◽

Global Ocean ◽

Residual Fraction ◽

Ferromanganese Crusts ◽

Sequential Leaching ◽

Bottom Waters ◽

Complementary Techniques ◽

Chukchi Borderland

Ferromanganese (FeMn) crusts from Mendeleev Ridge, Chukchi Borderland, and Alpha Ridge, in the Amerasia Basin, Arctic Ocean, are similar based on morphology and chemical composition. The crusts are characterized by a two- to four-layered stratigraphy. The chemical composition of the Arctic crusts differs significantly from hydrogenetic crusts from elsewhere of global ocean by high mean Fe/Mn ratios, high As, Li, V, Sc, and Th concentrations, and high detrital contents. Here, we present element distributions through crust stratigraphic sections and element phase association using several complementary techniques such as SEM-EDS, LA-ICP-MS, and sequential leaching, a widely employed method of element phase association that dissolves mineral phases of different stability step-by-step: Exchangeable cations and Ca carbonates, Mn-oxides, Fe-hydroxides, and residual fraction. Sequential leaching shows that the Arctic crusts have higher contents of most elements characteristic of the aluminosilicate phase than do Pacific crusts. Elements have similar distributions between the hydrogenetic Mn and Fe phases in all the Arctic and Pacific crusts. The main host phases for the elements enriched in the Arctic crusts over Pacific crusts (Li, As, Th, and V) are the Mn-phase for Li and Fe-phase for As, Th, and V; those elements also have higher contents in the residual aluminosilicate phase. Thus, higher concentrations of Li, As, Th, and V likely occur in the dissolved and particulate phases in bottom waters where the Arctic crusts grow, which has been shown to be true for Sc, also highly enriched in the crusts. The phase distributions of elements within the crust layers is mostly consistent among the Arctic crusts, being somewhat different in element concentrations in the residual phase.

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Petrology of volcanic rocks from an aseismic rise: Implications for the origin of the Rio Grande rise, South Atlantic Ocean

Earth and Planetary Science Letters ◽

10.1016/0012-821x(77)90125-x ◽

1977 ◽

Vol 35 (2) ◽

pp. 225-233 ◽

Cited By ~ 25

Author(s):

R.V. Fodor ◽

J.W. Husler ◽

Naresh Kumar

Keyword(s):

Atlantic Ocean ◽

Volcanic Rocks ◽

Rio Grande ◽

South Atlantic ◽

South Atlantic Ocean

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Adaptability and stability of white oat cultivars in relation to chemical composition of the caryopsis

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2013000100006 ◽

2013 ◽

Vol 48 (1) ◽

pp. 42-50 ◽

Cited By ~ 9

Author(s):

Maraisa Crestani Hawerroth ◽

Fernando Irajá Félix de Carvalho ◽

Antonio Costa de Oliveira ◽

José Antonio Gonzalez da Silva ◽

Luiz Carlos Gutkoski ◽

...

Keyword(s):

Chemical Composition ◽

Avena Sativa ◽

Block Design ◽

Chemical Properties ◽

Rio Grande ◽

Rio Grande Do Sul ◽

Average Performance ◽

Randomized Block Design ◽

Nitrogen Free Extract ◽

Oat Cultivars

The objective of this work was to characterize the chemical properties of white oat (Avena sativa) caryopsis and to determine the adaptability and stability of cultivars recommended for cultivation in the state of Rio Grande do Sul, Brazil. The trials were carried out in the 2007, 2008 and 2009 crop seasons, in three municipalities: Augusto Pestana, Capão do Leão, and Passo Fundo. Fifteen cultivars were evaluated in a randomized block design, with four replicates. The contents of protein, lipid, and nitrogen-free extract were evaluated in the caryopsis. Cultivar performances for the measured characters varied according to location and year of cultivation. The cultivar URS Guapa showed high content of nitrogen-free extract and low contents of protein and lipid in the caryopsis. 'FAPA Louise' showed high content of lipid, whereas 'Albasul', 'UPF 15', and 'UPF 18' showed high content of protein and low content of nitrogen-free extract. There is no evidence of an ideal biotype for the evaluated characters, which could simultaneously show high average performance, adaptability to favorable and unfavorable environments, and stability.

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Abundance and Microbial Diversity from Surface to Deep Water Layers Over the Rio Grande Rise, South Atlantic

10.1101/2021.04.22.441028 ◽

2021 ◽

Author(s):

Juliana Correa Neiva Ferreira ◽

Natascha M. Bergo ◽

Pedro M. Tura ◽

Mateus Gustavo Chuqui ◽

Frederico P. Brandini ◽

...

Keyword(s):

Microbial Community ◽

Microbial Diversity ◽

Rio Grande ◽

South Atlantic ◽

Water Masses ◽

16S Rrna Genes ◽

Rrna Genes ◽

List Type ◽

Tropical Water ◽

Southwestern Atlantic Ocean

AbstractMarine microbes control the flux of matter and energy essential for life in the oceans. Until now, the distribution and diversity of planktonic microorganisms above Fe-Mn crusts has received relatively little attention. Future mining\dredging of these minerals is predicted to affect microbial diversity and functioning in the deep sea. Here, we studied the ecology of planktonic microbes among pelagic environments of an Fe-Mn deposit region, at Rio Grande Rise, Southwestern Atlantic Ocean. We investigated microbial community composition using high-throughput sequencing of 16S rRNA genes and their abundance estimated by flow cytometry. Our results showed that the majority of picoplanktonic was found in epi- and mesopelagic waters, corresponding to the Tropical Water and South Atlantic Central Water. Bacterial and archaeal groups related to phototrophy, heterotrophy and chemosynthesis, such as Synechococcales, Sar11 (Proteobacteria) and Nitrosopumilales (Thaumarchaeota) were the main representatives of the pelagic microbial community. Additionally, we detected abundant assemblages involved in biodegradation of marine organic matter and iron oxidation at deep waters, i.e., Pseudoalteromonas and Alteromonas. No differences were observed in microbial community alpha diversity. However, we detected differences in community structure between water masses, suggesting that changes in an environmental setting (i.e. nutrient availability or circulation) play a significant role in structuring the pelagic zones, also affecting the meso- and bathypelagic microbiome.HighlightsRio Grande Rise pelagic microbiomePicoplankton carbon biomass partitioning through pelagic zonesUnique SAR11 Clade I oligotype in the shallowest Tropical WaterHigher number of shared oligotypes between deepest water massesNitrogen, carbon and sulfur may be important contributors for the pelagic microbiome

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Mollusca, Bivalvia, Cuspidariidae, Plectodon braziliensis (E. A. Smith, 1915) n. comb.: record of the genus for the South Atlantic, off Brazil

Check List ◽

10.15560/6.4.648 ◽

2010 ◽

Vol 6 (4) ◽

pp. 648 ◽

Cited By ~ 1

Author(s):

Daniel M. Pimpão ◽

Inga L. Veitenheimer-Mendes ◽

Fabrizio Scarabino

Keyword(s):

Type Species ◽

Rio Grande ◽

First Record ◽

South Atlantic ◽

New Combination ◽

Rio Grande Do Sul ◽

The South ◽

Scientific Collections

An analysis of bivalves shells collected off the coast of Rio Grande, Rio Grande do Sul, Brazil and specimens of scientific collections, identified as Cuspidaria braziliensis E. A. Smith, 1915 was made. From the examination of syntypes of C. braziliensis and the type species of the genus Plectodon Carpenter, 1864, a redescription was made and it is proposed to transfer the species to the genus Plectodon, resulting in the new combination Plectodon braziliensis (E.A. Smith, 1915). This is the first record of a Plectodon species for the South Atlantic.

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CHEMICAL CHARACTERIZATION OF ATMOSPHERIC PARTICLES IN URBAN AREAS OF RIO GRANDE DO SUL, BRAZIL-PRELIMINARY STUDY

Southern Brazilian Journal of Chemistry - Southern Brazilian Journal of Chemistry, Volume 28, No. 28, 2020 ◽

10.48141/sbjchem.v14.n14.2006.3_2006.pdf ◽

2006 ◽

Vol 14 (14) ◽

pp. 1-16

Author(s):

E. Teixeira ◽

J. Fachel Braga ◽

J.D. D. Migliavacca ◽

M.L.L.Fomoso Sanchez

Keyword(s):

Chemical Composition ◽

Urban Areas ◽

Chemical Characterization ◽

Rio Grande ◽

Atmospheric Particles ◽

Rio Grande Do Sul ◽

Power Stations ◽

Cluster Data ◽

Steel Industries

This work reports the determination of the concentration and chemical composition of atmospheric particles in the urban districts of Charqueadas and Sapucaia do Sul, State of Rio Grande do Sul, Brazil. Chemical composition, morphology, and particle size were analyzed using a scanning electron microscope with energy dispersive x=ray microanalysis (SEM-EDS). Cluster analysis showed that there were six types of particles: Fe-Zn, Fe, Si=Al, Si, Ca-S, and Na. Factorial analysis from cluster data showed that particles rich in Fe-Zn, Si-Al, and Ca-S appeared more frequently, indicating anthropogenic influence (vehicles, steel plants, coal-fired power stations). The experimental results and consideration of the wind directions show that the main source of pollution in Charqueadas appears to be due to coal mining and steel industries, while in Sapucaia do Sul due to steel plants and vehicles.

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Genesis and Evolution of Ferromanganese Crusts from the Summit of Rio Grande Rise, Southwest Atlantic Ocean

Minerals ◽

10.3390/min10040349 ◽

2020 ◽

Vol 10 (4) ◽

pp. 349 ◽

Cited By ~ 3

Author(s):

Mariana Benites ◽

James R. Hein ◽

Kira Mizell ◽

Terrence Blackburn ◽

Luigi Jovane

Keyword(s):

Atlantic Ocean ◽

Shallow Water ◽

Water Column ◽

Rio Grande ◽

Intermediate Water ◽

Mode Water ◽

Southwest Atlantic ◽

Ferromanganese Crusts ◽

Depositional Processes ◽

Water Depths

The Rio Grande Rise (RGR) is a large elevation in the Atlantic Ocean and known to host potential mineral resources of ferromanganese crusts (Fe–Mn), but no investigation into their general characteristics have been made in detail. Here, we investigate the chemical and mineralogical composition, growth rates and ages of initiation, and phosphatization of relatively shallow-water (650–825 m) Fe–Mn crusts dredged from the summit of RGR by using computed tomography, X-ray diffraction, 87Sr/86Sr ratios, U–Th isotopes, and various analytical techniques to determine their chemical composition. Fe–Mn crusts from RGR have two distinct generations. The older one has an estimated age of initiation around 48–55 Ma and was extensively affected by post-depositional processes under suboxic conditions resulting in phosphatization during the Miocene (from 20 to 6.8 Ma). As a result, the older generation shows characteristics of diagenetic Fe–Mn deposits, such as low Fe/Mn ratios (mean 0.52), high Mn, Ni, and Li contents and the presence of a 10 Å phyllomanganate, combined with the highest P content among crusts (up to 7.7 wt %). The younger generation is typical of hydrogenetic crusts formed under oxic conditions, with a mean Fe/Mn ratio of 0.75 and mean Co content of 0.66 wt %, and has the highest mean contents of Bi, Nb, Ni, Te, Rh, Ru, and Pt among crusts formed elsewhere. The regeneration of nutrients from local biological productivity in the water column is the main source of metals to crusts, providing mainly metals that regenerate rapidly in the water column and are made available at relatively shallow water depths (Ni, As, V, and Cd), at the expense of metals of slower regeneration (Si and Cu). Additionally, important contributions of nutrients may derive from various water masses, especially the South Atlantic Mode Water and Antarctic Intermediate Water (AAIW). Bulk Fe–Mn crusts from the summit of RGR plateau are generally depleted in metals considered of greatest economic interest in crusts like Co, REE, Mo, Te, and Zr, but are the most enriched in the critical metals Ni and Li compared to other crusts. Further investigations are warranted on Fe–Mn crusts from deeper-water depths along the RGR plateau and surrounding areas, which would less likely be affected by phosphatization.

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