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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 <span class="search-highlight">Gamohaan</span> <span class="search-highlight">Formation</span> (South Africa) microfossils compare...
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 <span class="search-highlight">Gamohaan</span> <span class="search-highlight">Format</span>...
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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Stratigraphic variations in chemistry and isotopic compositions of samples ...
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...
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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Representative Raman spectra of kerogen within fossiliferous <span class="search-highlight">Gamohaan</span> Forma...
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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Complex microbialites from the ~2,52 Ga Transvaal Supergroup. ( A ) Domical...
Published: 01 March 2021
Formation. ( C ) Cuspate-fenestrate and tented microbialites from the Gamohaan Formation. ( D ) Growth model for cuspate-fenestrate microbialites (e.g. the arrowed region in (C); these microbialites comprise upward-growing supports, over which undulating drapes develop. (A) from Sumner and Grotzinger (2004
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Geologic context of sampling locations. A: Simplified geologic map of Griqu...
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
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Probability distributions of δ 56 Fe pyrite  of well-sampled pre- or syn–Gr...
Published: 31 January 2020
–FeSaq = –2.2‰ for kinetic isotope effects (KIEs) in pyrite precipitation from FeS ( Guilbaud et al., 2011 ). Rooihoogte and Timeball Hill Formations, South Africa; Mount McRae Shale Formation, Western Australia; Gamohaan Formation, South Africa; Lokamonna Formation, South Africa; Jeerinah Formation
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Probability distributions of δ 56 Fe pyrite  of well-sampled pre- or syn–Gr...
Published: 31 January 2020
–FeSaq = –2.2‰ for kinetic isotope effects (KIEs) in pyrite precipitation from FeS ( Guilbaud et al., 2011 ). Rooihoogte and Timeball Hill Formations, South Africa; Mount McRae Shale Formation, Western Australia; Gamohaan Formation, South Africa; Lokamonna Formation, South Africa; Jeerinah Formation
Series: Geological Society, London, Special Publications
Published: 01 January 2000
DOI: 10.1144/GSL.SP.2000.178.01.05
EISBN: 9781862394261
... and giant ooids, 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...
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Journal Article
Journal: Geology
Published: 01 November 2013
Geology (2013) 41 (11): 1147–1150.
..., 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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Petrography and REE + Y systematics in a  Conophyton  stromatolite of the 2...
Published: 17 September 2014
Fig. 10. Petrography and REE + Y systematics in a Conophyton stromatolite of the 2.52 Ga Gamohaan Formation. ( a ) Transmitted light photograph of the entire thin section. This clearly illustrates the three carbonate types, consisting of black microbial structures ( Conophyton ) early directed
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Photomicrographs of representative coccoidal microfossils from <span class="search-highlight">Gamohaan</span> For...
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 Abstract Microbialites 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...
Journal Article
Published: 01 March 2021
South African Journal of Geology (2021) 124 (1): 225–252.
... Formation. ( C ) Cuspate-fenestrate and tented microbialites from the Gamohaan Formation. ( D ) Growth model for cuspate-fenestrate microbialites (e.g. the arrowed region in (C); these microbialites comprise upward-growing supports, over which undulating drapes develop. (A) from Sumner and Grotzinger (2004...
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Journal Article
Published: 17 September 2014
Journal of the Geological Society (2014) 171 (6): 745–763.
...Fig. 10. Petrography and REE + Y systematics in a Conophyton stromatolite of the 2.52 Ga Gamohaan Formation. ( a ) Transmitted light photograph of the entire thin section. This clearly illustrates the three carbonate types, consisting of black microbial structures ( Conophyton ) early directed...
FIGURES | View All (10)
Journal Article
Journal: Geology
Published: 16 April 2019
Geology (2019) 47 (6): 559–562.
... ( Fig. 2B ). IF deposits analyzed during this period present a maximum value between 0.97‰ and 1.76‰. New data from 2.52 Ga carbonate samples from the Gamohaan Formation, Griqualand West basin, show a maximum δ 98 Mo of 1.11‰, in line with elevated values observed for carbonates of the adjacent...
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