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Rasthof Formation

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Series: Geological Society, London, Special Publications, Geological Society, London, Special Publications
Published: 01 January 2015
DOI: 10.1144/SP418.7
EISBN: 9781862397163
... Study of the microbial facies of Cryogenian carbonates, such as the Rasthof Formation, is essential for several reasons. First, they represent viable reservoir targets within the frontier Owambo Basin of northern Namibia and southern Angola. Second, age-equivalent microbial carbonates belong...
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Series: Geological Society, London, Special Publications, Geological Society, London, Special Publications
Published: 01 January 2007
DOI: 10.1144/SP286.7
EISBN: 9781862395343
... Abstract The lower cap carbonate (Rasthof Formation) overlies Neoproterozoic glacial deposits (Chuos Formation) and is exposed in the Khowarib-Warmquelle area in Northern Namibia. The basal 14.2 m part of the Rasthof Formation (total about 220 m) consists of the carbonate rhythmite...
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Geological map of the <b>Rasthof</b> <b>Formation</b> showing the fossiliferous localitie...
in > PALAIOS
Published: 01 February 2013
FIGURE 1— Geological map of the Rasthof Formation showing the fossiliferous localities. Inset map of Namibia in southern Africa shows mapped area in the north. Geological map shows the four localities: Ombepera  =  A, South Ombepera  =  B, Okaaru  =  C, and Ongongo  =  D. Stratigraphic names used
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Stratigraphic columns of the <b>Rasthof</b> <b>Formation</b> at the four localities. Colo...
in > PALAIOS
Published: 01 February 2013
FIGURE 2— Stratigraphic columns of the Rasthof Formation at the four localities. Colored dots at Ombepera and South Ombepera mark the stratigraphic positions of fossiliferous and unfossiliferous samples, respectively. Fossiliferous samples from Ongongo and Okaaru described in Bosak et al. (2011a
Image
Representative morphologies of tubular tests from <b>Rasthof</b> <b>Formation</b> (Namibi...
in > Geology
Published: 01 January 2012
Figure 2. Representative morphologies of tubular tests from Rasthof Formation (Namibia). All images are scanning electron micrographs. A−E: Tubular tests with transverse constrictions ( t ) and folds ( f ). F: Aperture of B showing small mineral grains on exterior and in lumen (arrows). G
Journal Article
Journal: PALAIOS
Published: 01 February 2013
PALAIOS (2013) 28 (2): 67–79.
...FIGURE 1— Geological map of the Rasthof Formation showing the fossiliferous localities. Inset map of Namibia in southern Africa shows mapped area in the north. Geological map shows the four localities: Ombepera  =  A, South Ombepera  =  B, Okaaru  =  C, and Ongongo  =  D. Stratigraphic names used...
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Journal Article
Journal: Geology
Published: 21 October 2020
Geology (2021) 49 (3): 263–267.
...) contains abundant dropstone-bearing intervals and striated clasts. It is capped by the Rasthof Formation, composed of laminites in its lower portion and microbial carbonates above. These laminites are locally found to contain pebble- and granule-sized lonestones in abundance. At the Omutirapo outcrop...
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Journal Article
Journal: Geology
Published: 01 January 2012
Geology (2012) 40 (1): 67–70.
...Figure 2. Representative morphologies of tubular tests from Rasthof Formation (Namibia). All images are scanning electron micrographs. A−E: Tubular tests with transverse constrictions ( t ) and folds ( f ). F: Aperture of B showing small mineral grains on exterior and in lumen (arrows). G...
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(A) Outcrop view of section at <b>Rasthof</b> Farm (Namibia), showing vertically i...
in > Geology
Published: 21 October 2020
Figure 4. (A) Outcrop view of section at Rasthof Farm (Namibia), showing vertically inclined strata that young toward the left side. Position of the profile in Figure 2 is shown; i.e., location of the lonestone-bearing strata in the Rasthof Formation. Field of view in foreground is ∼50 m. (B
Journal Article
Journal: GSA Bulletin
Published: 23 June 2017
GSA Bulletin (2017) 129 (9-10): 1280–1299.
...–Ediacaran portion of this record include (1) negative δ 13 C carb excursions in cap carbonates overlying Cryogenian glacigenic deposits of the Areyonga and Olympic Formations (i.e., the Rasthof and Maieberg excursions, respectively); (2) a mid-Cryogenian negative excursion in the Ringwood Member...
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Journal Article
Journal: Geosphere
Published: 01 June 2017
Geosphere (2017) 13 (3): 811–837.
... and fracture- or cleavage-controlled Fe mineralization are ubiquitous—frustrates attempts to discern the original distribution of Fe within the Chuos Formation. The Chuos Formation is conformably but sharply overlain by the Rasthof (a.k.a. Berg Aukas) Formation, a distinctive Sturtian “cap carbonate...
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Columnar sections of the Chuos <b>Formation</b> diamictite wedge in the southweste...
in > Geosphere
Published: 01 June 2017
Figure 16. Columnar sections of the Chuos Formation diamictite wedge in the southwestern half of the Vrede south dome ( Fig. 10 ), showing its relations to the Ugab Subgroup, to the Rasthof and Narachaams Formations of the nonglacial Abenab Subgroup (Cryogenian), to the Marinoan glacial erosion
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Columnar sections of the lower Naauwpoort(?) and Chuos <b>Formations</b> in the To...
in > Geosphere
Published: 01 June 2017
Figure 19. Columnar sections of the lower Naauwpoort(?) and Chuos Formations in the Toekoms syn-glacial half graben (see Fig. 17 and satellite view inset for locations). Vertical datum (0 m) is the base of the Rasthof Formation cap limestone. Note the thin glacigenic diamictite directly beneath
Journal Article
Published: 29 August 2017
Geological Magazine (2017) 154 (6): 1269–1284.
... of the Dengying structures appear to be frame building. In addition, the Cryogenian structures from South Australia were estimated to have developed in a palaeo-water-depth of greater than 150 m (Wallace et al. 2015 ). The microbial member of the Rasthof Formation, where the Namibian chambered structures...
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Journal Article
Journal: Geology
Published: 01 September 2004
Geology (2004) 32 (9): 817–820.
..., the older Chuos Formation consists of basement-clast–dominated dia mictite and iron formation capped by the very dark gray Rasthof dolostone ( Hoffmann and Prave, 1996 ; Hoffman et al., 1998 ) passing into decameter-scale, upward-shallowing and upward-thickening carbonate packages (Abenab Subgroup...
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Series: Geological Society, London, Memoirs, Geological Society, London, Memoirs
Published: 01 January 2011
DOI: 10.1144/M36.29
EISBN: 9781862394117
..., Tarim or Australia. Although the diamictites of the Dzabkhan basin have not been directly dated radiometrically, maximum age constraints on the glacial deposits are provided by zircons from rhyolites within the Dzabkhan Formation of 777±6 Ma ( Zhao et al. 2006 ), 803.4±8.0 and 773.5±3.6 Ma (U–Pb...
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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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Series: Geological Society, London, Memoirs, Geological Society, London, Memoirs
Published: 01 January 2011
DOI: 10.1144/M36.15
EISBN: 9781862394117
..., cauliflower chert and enterolithic bedding. The tops of some beds exhibit desiccation cracks. Direct age constraints are also lacking for the base of the Witvlei Group, but can be inferred from the proposed correlation of the Gobabis Member and Blaubeker Formation with the Rasthof cap carbonate and Chuos...
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(A) Stratigraphy of the Otavi Group, Namibia. Maximum age constraint for th...
in > Geology
Published: 21 October 2020
age from U-Pb dating of ash beds ( Hoffman et al., 1996 ). (B) Summary sedimentary logs of the uppermost part of the Chuos Formation (base not shown) and the lower part of the Rasthof Formation at both Omutirapo and Rasthof Farm. VC—very coarse.
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Field images from the syn-glacial half graben on Toekoms farm. (A) View loo...
in > Geosphere
Published: 01 June 2017
black band is the Rasthof Formation (unit Ar) cap limestone. (B) Parallel-laminated silty argillite in the upper part of columnar section N. (C) Ice-rafted dropstones of granodiorite (G) and quartz-arenite (Q) in parallel-laminated silty argillite from the upper part of columnar section N. (D) Graded