Earth:Angwa Sandstone
Angwa Sandstone Stratigraphic range: Triassic ~252–210 Ma | |
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Angwa sandstone boulder from Chirundu Hill, Hurungwe District, Zimbabwe | |
Type | Geological formation |
Unit of | Upper Karoo Group, Karoo Supergroup |
Sub-units | Alternations Mb. Massive Sandstone Mb.[1] |
Underlies | Pebbly Arkose Formation |
Overlies | Lower Karoo Group |
Lithology | |
Primary | Sandstone |
Other | Siltstone |
Location | |
Coordinates | [ ⚑ ] : 16°06′25″S 30°18′25″E / 16.107°S 30.307°E[1] |
Country | Mozambique Zambia Zimbabwe |
Type section | |
Named for | Angwa River, Zimbabwe |
Named by | P.M. Oesterlen, Zimbabwe Geological Survey[2] |
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The Angwa Sandstone is a geological formation of the mid-Triassic Cabora Bassa Basin [1]and Mana Pools Basin [3]of southern Africa, consisting mainly of sandstone.[4]
Description
Stratigraphy
The Angwa Sandstone is the lowest formation in the Upper Karoo Group of the Karoo Supergroup, underlying the Pebbly Arkose Formation and overlying the Lower Karoo Group.[5] The formation is divided into two members: the Alternations Member and the Massive Sandstone (Chirambakadoma) Member.[1]
The Angwa Sandstone has been correlated to the Molteno Formation of the Great Karoo Basin, South Africa,[6][1] and to the Escarpment Grit of the Mid-Zambezi Basin.[7]
Lithology
The formation is a sedimentary unit, consisting mainly of fluvial sands and silts.[1]
It has been dated as covering rocks from much of the Triassic, with pollen and flora identified from the Induan, and Ladinian to Norian.[6][8]
Occurrence
The Angwa Sandstone Formation is found in Mozambique, Zambia, Zimbabwe, in the Mana Pools and Cabora Bassa Basins.
Fossil Content
Pinales of the Angwa Sandstone | ||||
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Genus | Presence | Notes | Images | |
Dadoxylon | Mbire District and Chirundu, Zimbabwe |
Callistophytaceae (Pteridospermopsida) of the Angwa Sandstone | ||||
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Genus | Presence | Notes | Images | |
Lepidopteris | Manyima River, Mbire District, Zimbabwe | |||
Dicroidium | Manyima River, Mbire District, Zimbabwe |
Ginkgoales of the Angwa Sandstone | ||||
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Genus | Presence | Notes | Images | |
Sphenobaiera | Manyima River, Mbire District, Zimbabwe |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 P. M. Oesterlen; B. D. Millsteed (1994). "Lithostratigraphy, palaeontology, and sedimentary environments of the western Cabora Bassa Basin, lower Zambezi Valley, Zimbabwe". South African Journal of Geology 97: 205–224. https://journals.co.za/doi/pdf/10.10520/AJA10120750_662.
- ↑ 2.0 2.1 P.M. Oesterlen (1990). "The geology of the Dande West area (western Cabora Bassa Basin) - a preliminary report". Annals of the Zimbabwe Geological Survey 14: 12–20.
- ↑ Oesterlem, P.M. (2001). "New geological results from the Mana Pools basin of Zimbabwe, Lower Zambezi Graben". Annals of the Zimbabwe Geological Survey 16: 17-26. https://www.africabib.org/rec.php?RID=Q00041698. Retrieved 15 January 2024.
- ↑ Moore, A.E.; Cotterill, F.P.D.; Broderick, T.; Plowes, D. (2009). "Landscape evolution in Zimbabwe from the Permian to present, with implications for kimberlite prospecting". South African Journal of Geology 112: 65–88. doi:10.2113/gssajg.112.1.65. https://pubs.geoscienceworld.org/gssa/sajg/article-abstract/112/1/65/141291/Landscape-evolution-in-Zimbabwe-from-the-Permian?redirectedFrom=fulltext.
- ↑ Oesterlen, P.M.; Blenkinsop, T.G. (1994). "Extension directions and strain near the failed triple junction of the Zambezi and Luangwa Rift zones, southern Africa". Journal of African Earth Sciences 18 (2): 175. doi:10.1016/0899-5362(94)90029-9. Bibcode: 1994JAfES..18..175O.
- ↑ 6.0 6.1 d'Engelbronner, E.R. (1996). "New palynological data from Karoo sediments, Mana Pools basin, northern Zimbabwe". Journal of African Earth Sciences 23 (1): 17–30. doi:10.1016/S0899-5362(96)00049-8. Bibcode: 1996JAfES..23...17D.
- ↑ Catuneanu, O.; Wopfner, H.; Eriksson, P.G.; Cairncross, B.; Rubidge, B.S.; Smith, R.M.H.; Hancox, P.J. (2005). "The Karoo basins of south-central Africa". Journal of African Earth Sciences 43 (1–3): 211–253. doi:10.1016/j.jafrearsci.2005.07.007. Bibcode: 2005JAfES..43..211C.
- ↑ 8.0 8.1 8.2 8.3 G. Barale; M. Bamford; B. Gómez; T.J. Broderick; M.A. Raath; A. Cadman (2005). "A fossil peat deposit from the Late Triassic (Carnian) of Zimbabwe with preserved cuticle of Pteridospermopsida and Ginkgoales, and its geological setting". Palaeontologia Africana 41: 89–100. http://hal.archives-ouvertes.fr/hal-00156797/.
- ↑ D. Love (1997). "The geology of the Chirundu area, Zambezi Valley". Annals of the Zimbabwe Geological Survey 18: 18–26.
Original source: https://en.wikipedia.org/wiki/Angwa Sandstone.
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