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Gamohaan Formation

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Journal Article
Journal: Geology
Published: 01 December 2016
Geology (2016) 44 (12): 983-986.
... preserved in a deep-water black chert in the Gamohaan Formation of the Kaapvaal craton of South Africa. These fossils occur mainly as compressed solitary coccoids that range in size from 20 to 265 µm but occasionally occur in short chains of cells. Morphologically these fossils are similar to Proterozoic...
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Size distribution of <b>Gamohaan</b> <b>Formation</b> (South Africa) microfossils compare...
in > Geology
Published: 01 December 2016
Figure 3. Size distribution of Gamohaan Formation (South Africa) microfossils compared with other coccoidal microbes. Distribution of maximum cell diameters of well-preserved microfossils from this study imaged in plan view (dark gray area) compared with modern Thiomargarita namibiensis cells
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Map showing sampling locations Kuruman and Alphen farm. The <b>Gamohaan</b> <b>Format</b>...
Published: 01 July 2014
Figure 1 Map showing sampling locations Kuruman and Alphen farm. The Gamohaan Formation is the uppermost unit of the Campbellrand Subgroup, which consists of a carbonate platform, overlying the mixed siliciclastic-carbonate Schmidtsdrif Subgroup (Beukes, 1987; Sumner and Beukes, 2006
Journal Article
Published: 01 July 2014
Journal of Paleontology (2014) 88 (4): 719-726.
...Figure 1 Map showing sampling locations Kuruman and Alphen farm. The Gamohaan Formation is the uppermost unit of the Campbellrand Subgroup, which consists of a carbonate platform, overlying the mixed siliciclastic-carbonate Schmidtsdrif Subgroup (Beukes, 1987; Sumner and Beukes, 2006...
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Journal Article
Published: 01 December 2002
South African Journal of Geology (2002) 105 (4): 381-400.
... provides new lithofacies descriptions and suggests formation boundary positions for the upper Campbellrand Subgroup stratigraphy exposed by the open pit and underground tunnel network at the mine. The Klippan Formation lagoonal facies, the Kogelbeen Formation subtidal facies and the Gamohaan Formation...
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Series: Geological Society, London, Special Publications
Published: 01 January 2000
DOI: 10.1144/GSL.SP.2000.178.01.05
EISBN: 9781862394261
..., from the Late Archaean Ghaap Group of South Africa have provided compelling evidence for an intimate relationship between taphonomic evolution, fabric development and mineralogy in rocks of the Gamohaan and Boomplaas formations. Cements, both in fold hinges and between the limbs of slump-folded...
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Representative Raman spectra of kerogen within fossiliferous <b>Gamohaan</b> Forma...
in > Geology
Published: 01 December 2016
Figure 4. Representative Raman spectra of kerogen within fossiliferous Gamohaan Formation (South Africa) black chert. The Raman bands at ∼1360 cm –1 and ∼1600 cm –1 are characteristic of kerogen. Upper spectrum is from coccoidal microfossil pictured in Figure 2A . Lower spectrum is from
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Photomicrographs of representative coccoidal microfossils from <b>Gamohaan</b> For...
in > Geology
Published: 01 December 2016
Figure 2. Photomicrographs of representative coccoidal microfossils from Gamohaan Formation (South Africa) and modern Thiomargarita sp. A–I: Fossils photographed in thin sections cut parallel to bedding showing approximate cross-sectional shape of organisms in life. J,K: Modern Thiomargarita
Journal Article
Journal: PALAIOS
Published: 01 August 1997
PALAIOS (1997) 12 (4): 302-318.
...Dawn Y. Sumner AbstractMicrobialites in the 2521+ or -3 Ma Gamohaan and Frisco formations, South Africa, consist of three components: very thin, filmy laminae that are interpreted as remnants of microbial mats; irregular surfaces that acted as supports over which filmy laminae draped, which also...
Series: Reviews in Economic Geology
Published: 01 January 2008
DOI: 10.5382/Rev.15.01
EISBN: 9781629490229
... formations noted in text). F ig . 12. Correlations of organic carbon and Al 2 O 3 (A) and sulfur (B) contents in the transition zone between the Gamohaan carbonate and Kuruman Iron Formation successions (modified after Klein and Beukes, 1989 ). F ig . 5. Schematic comparison between...
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Journal Article
Journal: Geology
Published: 01 November 2013
Geology (2013) 41 (11): 1147-1150.
... the Gamohaan Formation and overlying Kuruman Iron Formation (Fig. DR1 in the GSA Data Repository 1 ). Gamohaan Formation samples include carbonaceous limestone and dolomites, as well as carbonaceous siliciclastic units and ankerite and/or ferroan dolomite chert units of the Tsineng Member that reflect...
FIGURES
Series: SEPM Special Publication
Published: 01 January 2000
DOI: 10.2110/pec.00.66.0007
EISBN: 9781565761889
... and degradation of cyanobacteria, which may produce ideal conditions for dolomite formation. The role of benthic microbial communities should therefore be considered and tested in future research ( McKenzie, personal communication, 1997 ). The Gamohaan stromatolites display textural and miner- alogical features...
Journal Article
Published: 01 March 2002
South African Journal of Geology (2002) 105 (1): 75-92.
... onto the stable carbonate platform. This fluid leached metals from the Ventersdorp mafic volcanics, later depositing them in vesicles that became amygdales and higher up the succession in the Steekdorings Member of the Reivilo Formation at Pering and the Bushy Park Member of the Gamohaan Formation...
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Journal Article
Journal: GSA Bulletin
Published: 01 January 2009
GSA Bulletin (2009) 121 (1-2): 222-235.
...Woodward W. Fischer; Woodward W. Fischer; Andrew H. Knoll AbstractIron formations are typically thinly bedded or laminated sedimentary rocks containing 15% or more of iron and a large proportion of silica (commonly >40%). In the ca. 2590–2460 Ma Campbellrand-Kuruman Complex, Transvaal...
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Stratigraphic variations in chemistry and isotopic compositions of samples ...
in > Geology
Published: 01 November 2013
, and initial 87 Sr/ 86 Sr ratios from carbonates are shown. Blue symbols—Kogelbeen (Kog) and lower Gamohaan Formations, gray symbols—transition between Ca-Mg carbonate and iron formation (Tsineng Member of Gamohaan Formation), red symbols—Kuruman Iron Formation. See the Data Repository (see footnote 1
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Fe contents (mol% FeCO 3 ) and Fe, C, and O isotope compositions (from  Hei...
in > Geology
Published: 01 November 2013
Figure 1. Fe contents (mol% FeCO 3 ) and Fe, C, and O isotope compositions (from Heimann et al., 2010 ) versus initial 87 Sr/ 86 Sr ratios (this study) for carbonates from Kuruman Iron Formation and Gamohaan Formation, South Africa. Isotopic compositions for carbonates in equilibrium (equil
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Geologic context of sampling locations. A: Simplified geologic map of Griqu...
in > Geology
Published: 01 December 2016
location of Kaapvaal craton and Neoarchean Griqualand West Basin. B: Simplified stratigraphic column of Gamohaan Formation showing increasing basin water depth during deposition and position of fossiliferous chert unit (adapted from Beukes and Gutzmer, 2008 ). Kogel.—Kogelbeen; KIF—Kuruman Iron Formation
Journal Article
Published: 01 June 2006
South African Journal of Geology (2006) 109 (1-2): 23-54.
... (Campbellrand Subgroup) to deeper-water banded iron formations (Asbestos Hills Subgroup). The cores were drilled in proximal (core GKF01) and distal (core GKP01) positions relative to the margin of the Campbellrand-Malmani carbonate platform. Correlation between cores is based on three types of marker horizons...
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Journal Article
Journal: Geology
Published: 01 September 2005
Geology (2005) 33 (9): 725-728.
... and Sumner, 2004 ), and the Kuruman layer ( Glikson, 2005b ). The age of the Monteville spherule layer is bracketed between 2642.2 ± 2.3 Ma, the age of a tuff in the Vryburg Formation (Schmidtsdriff Subgroup) ( Walraven and Martini, 1995 ), and 2521 ± 3 Ma, the age of a tuff in the Gamohaan Formation...
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Journal Article
Journal: Economic Geology
Published: 01 May 2010
Economic Geology (2010) 105 (3): 593-625.
... to 1.58 Ga was the following: (1) enhanced oxidation of sulfides in the crust that provided sulfate to the hydrosphere and Pb and Zn to sediments; (2) development of major redox and compositional gradients in the oceans; (3) first formation of significant sulfate-bearing evaporites; (4) formation of red...
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