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Urucum Formation

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Journal Article
Published: 01 May 2017
Journal of Paleontology (2017) 91 (3): 393-406.
... of the Neoproterozoic Urucum Formation (Jacadigo Group) of west-central Brazil, having an age constrained between 889±44 Ma (K-Ar; basement rocks) and 587±7 Ma ( 40 Ar/ 39 Ar age of early metamorphic cryptomelane in overlying manganese ore). Early isopachous carbonate cement entombed these VSMs, preserving rare direct...
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Journal Article
Published: 01 July 2019
Journal of Paleontology (2019) 93 (4): 612-627.
...L. Morais; D.J.G. Lahr; I.D. Rudnitzki; B.T. Freitas; G.R. Romero; S.M. Porter; A.H. Knoll; T.R. Fairchild Abstract Vase-shaped microfossils (VSMs) occur in dolostone clasts within conglomerates, breccias, and diamictites of the Neoproterozoic Urucum Formation, Jacadigo Group, southwest Brazil...
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Journal Article
Journal: Economic Geology
Published: 01 September 2004
Economic Geology (2004) 99 (6): 1233-1244.
.... † Corresponding author: e-mail, cklein@unm.edu 22 06 2004 13 08 2003 Economic Geology 2004 The Neoproterozoic iron and manganese deposits of the Urucum district are associated with banded iron-formations (BIF), locally known as jaspilites, and glaciomarine dropstone bands...
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Journal Article
Journal: Economic Geology
Published: 01 August 1992
Economic Geology (1992) 87 (5): 1375-1392.
...H. Urban; B. Stribrny; H. J. Lippolt Abstract The Urucum district is located in the Brazilian state of Mato Grosso do Sul near the city of Corumba on the Brazilian-Bolivian border. The district comprises an area of 200 km 2 , where eight up to 1,000-m-high tabular mountains rise out of the swampy...
Series: Geological Society, London, Special Publications
Published: 01 January 2019
DOI: 10.1144/SP475.2
EISBN: 9781786204141
... ). A microbial origin for some iron oxides has also been postulated for the iron formations of the Chuos Formation ( Le Heron et al. 2013 a ). Although some other NIFs contain substantial manganese, such as the iron and manganese formations of the Urucum District in Brazil ( Urban et al. 1992 ; Klein...
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Journal Article
Published: 30 January 2012
Canadian Journal of Earth Sciences (2012) 49 (2): 455-476.
...Geoffrey J. Baldwin; Elizabeth C. Turner; Balz S. Kamber Abstract Neoproterozoic iron formations record an unusual and apparently final recurrence of this sediment type after a hiatus of more than one billion years. Despite the unusual environmental conditions that led to their formation...
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Image
Plot of the major chemical oxide components of iron-<b>formations</b> with the ori...
Published: 01 October 2005
F igure 21. Plot of the major chemical oxide components of iron-formations with the original analytic results recalculated to 100% on an H 2 O-CO 2 -free basis. The shaded area enclosed by thin dashed lines brackets the overall range of all average values (except for the Rapitan and Urucum iron
Journal Article
Journal: Economic Geology
Published: 01 January 2013
Economic Geology (2013) 108 (1): 111-134.
...Albertus J.B. Smith; Nicolas J. Beukes; Jens Gutzmer Abstract This paper documents the sedimentological setting, mineralogy, and geochemistry of several iron formation units interbedded with siliciclastic strata of the Mesoarchean Witwatersrand Supergroup, well known for its world-class...
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Series: Reviews in Economic Geology
Published: 01 January 2008
DOI: 10.5382/Rev.15.06
EISBN: 9781629490229
... by the strongly supergene altered nature of intercalated manganese ores as well as extensive kaolinitization of the glacial erratics within the iron formation. Urucum iron ores are typically finely laminated, hard to somewhat friable, and composed of microcrystalline hematite, with no or very minor goethite...
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Series: Geological Society, London, Memoirs
Published: 01 January 2011
DOI: 10.1144/M36.5
EISBN: 9781862394117
... of modern seawater, and hydrothermal contributions are more diluted than in more ancient Fe formations. Economic Fe–Mn oxide ores of the Jacadigo Group occur in stratigraphically isolated fault blocks in the Urucum District of southwestern Brazil and adjacent Bolivia ( Dorr 1945 ; Walde et al. 1981...
FIGURES
Journal Article
Journal: Geology
Published: 01 March 2010
Geology (2010) 38 (3): 267-270.
... and Araras Formations), which are in turn overlain by siliciclastic rocks that may constitute a separate, unconformable unit ( Nogueira et al., 2007 ). For the Corumbá Group in the south ( Fig. 2B ), there is no exposed contact between the diamictites and manganiferous banded iron formations of the Urucum...
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Series: Geological Society, London, Memoirs
Published: 01 January 2011
DOI: 10.1144/M36.45
EISBN: 9781862394117
... Group ( Almeida 1945 ; Dorr II 1945 ; Almeida 1946 ) is exposed in some hills south of the town of Corumbá extending into Bolivia. The Urucum Fm. (lower unit) is characterized by conglomerate and arkose and is overlain by the economic manganesiferous bed and banded iron formation (BIF) of the Santa...
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Journal Article
Journal: Economic Geology
Published: 01 May 2010
Economic Geology (2010) 105 (3): 467-508.
...Andrey Bekker; John F. Slack; Noah Planavsky; Bryan Krapež; Axel Hofmann; Kurt O. Konhauser; Olivier J. Rouxel Abstract Iron formations are economically important sedimentary rocks that are most common in Precambrian sedimentary successions. Although many aspects of their origin remain unresolved...
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Journal Article
Published: 13 December 2016
Geological Magazine (2017) 154 (6): 1371-1380.
... , C. & Ladeira , E. A. 2004 . Geochemistry and mineralogy of neoproterozoic banded iron-formations and some selected, siliceous manganese formations from the Urucum district, Mato Grosso do Sul, Brazil . Economic Geology 99 (6) , 1233 –44. Koeppenkastrop , D. & Decarlo...
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Journal Article
Journal: Economic Geology
Published: 01 June 2017
Economic Geology (2017) 112 (4): 941-982.
... toward the footwall. The significant chemical influence and importance of country-rock lithologies as a possible elemental source, for example, must be taken into account when interpreting whole-rock geochemical data and investigating an itabirite-/banded iron formation-hosted iron ore system...
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Journal Article
Journal: Economic Geology
Published: 01 June 2012
Economic Geology (2012) 107 (4): 599-644.
...Thomas Angerer; Steffen G. Hagemann; Leonid V. Danyushevsky Abstract The banded iron formation (BIF)-hosted iron ore deposits in the lower greenstone succession of the Koolyanobbing greenstone belt, 50 km north of Southern Cross in Western Australia, are a ~200 Mt high-grade Fe (>58%) pre-mining...
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Series: Reviews in Economic Geology
Published: 01 January 2008
DOI: 10.5382/Rev.15.01
EISBN: 9781629490229
... and Beukes, 1993 ) and the Urucum district (e.g., Klein and Ladeira, 2004 ) along the western margin of the Amazon craton in South America (Fig. 4 ). Smaller Neoproterozoic iron formations are also known from the Damara-Gariep succession in Namibia and South Africa, the Flinders Range in Australia...
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Journal Article
Published: 01 October 2005
American Mineralogist (2005) 90 (10): 1473-1499.
...F igure 21. Plot of the major chemical oxide components of iron-formations with the original analytic results recalculated to 100% on an H 2 O-CO 2 -free basis. The shaded area enclosed by thin dashed lines brackets the overall range of all average values (except for the Rapitan and Urucum iron...
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Image
Photomicrographs of selected VSM species observed in petrographic thin sect...
Published: 01 July 2019
al., 2017 . ( 1 ) Carbonaceous test in dolostone clast, Urucum Formation (GP/5T-2536B); ( 2 ) siliceous mold in dolostone, Callison Lake Formation (J1204-16.8/EFS = Y46-1). ( 3 ) Palaeoamphora sp.? Siliceous mold in dolostone, Callison Lake Formation. ( 4–9 ) Pakupaku kabin Riedman et al., 2017
Journal Article
Journal: Economic Geology
Published: 01 November 2006
Economic Geology (2006) 101 (7): 1359-1376.
...Desmond F. Lascelles Abstract The banded iron formation (BIF)-hosted Hope Downs high-grade hematite ore deposits are situated within the Marra Mamba Iron Formation with subsidiary deposits in the Brockman Iron Formation of the Archean to Proterozoic Hamersley Group of Western Australia. The main...
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