Journal articles: 'Geology Africa'

1

Lüning, Sebastian. "Geology of North Africa." Episodes 35, no. 3 (September 1, 2012): 457. http://dx.doi.org/10.18814/epiiugs/2012/v35i3/009.

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Smith, Alan M. "Environmental geology, South Africa, and the South African Geological Survey." Environmental Geology and Water Sciences 18, no. 1 (July 1991): 1–2. http://dx.doi.org/10.1007/bf01704571.

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Lemenkova, Polina. "Geophysical Mapping of Ghana Using Advanced Cartographic Tool GMT." Kartografija i geoinformacije 20, no. 36 (February 15, 2022): 16–37. http://dx.doi.org/10.32909/kg.20.36.2.

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Ghana is a country exceptionally rich in geologic mineral resources with contrasting topographic relief and varied geophysical setting. This paper evaluated the geological and geophysical setting of Ghana with a special focus on the impact of the geologic setting and topography on gravity. Specifically, it assessed how variations in geology, topography, landscapes and the environment control the geophysical parameters and how these vary among the major regions of the country – the Volta Basin, Northern Plains, Ashanti-Kwahu (Kumasi) and Coastal Plains in the Accra surroundings. Previous studies utilizing traditional Geographic Information System (GIS) approaches have documented the geologic evolution of Ghana evolved as a part of the West African Craton. As a contribution to the existing research, this paper presents a regional analysis of Ghana by integrated mapping of geology, geophysics and topography of the country. The technical approach of this research focuses on utilizing the console-based scripting cartographic toolset Generic Mapping Tools (GMT) integrated with QGIS for processing and mapping the datasets: General Bathymetric Chart of the Oceans (GEBCO), Earth Gravitational Model 2008 (EGM-2008), gravity grids. The theoretical background is based on the geologic research of West Africa supported by high-resolution data. The paper defines a conceptual cartographic framework for integrated geologic and geophysical visualization in a regional-scale mapping project on Ghana.

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D'Avignon, Robyn. "Shelf Projects: The Political Life of Exploration Geology in Senegal." Engaging Science, Technology, and Society 4 (March 1, 2018): 111. http://dx.doi.org/10.17351/ests2018.210.

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Since the early 2000s, southeastern Senegal has emerged as a premier gold exploration and mining frontier. At present, the Sabodala gold mine, owned by the Canadian company Teranga Gold, is the only operational gold mine and mill in Senegal. But two more open-pit gold operations are scheduled to open this year, and several other companies have announced discoveries of industrial-scale deposits. By documenting the shifting ownership and exploration of the Sabodala deposit, this article draws attention to how the protracted phase of mineral research shapes the political life of mining operations in Africa and elsewhere in the global South. Geological exploration in colonial and post-colonial Senegal, as in much of Africa, has relied heavily on the expertise of indigenous miners and smelters. Mining Sabodala has thus unearthed multi-vocal and contested histories of gold discovery. Historians of science have established that field assistants and experts in Africa have produced agronomic and medical knowledge typically credited to “the West.” By extending this argument to gold exploration, the article brings African history into dialogue with an emergent anthropology of subterranean knowledge production.

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Ganguly, Pekham. "Medical Geology Related to Different Trace Elements Deficiency and Toxicity Diseases." International Journal for Research in Applied Science and Engineering Technology 11, no. 9 (September 30, 2023): 113–27. http://dx.doi.org/10.22214/ijraset.2023.55616.

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Abstract: Medical geology is an emerging discipline that, broadly defined, examines the public health impacts of geologic materials and geologic processes. Medical Geology, the study of the impacts of geologic materials and processes on animal and human health, is a dynamic emerging discipline bringing together the geosciences, biomedical, and public health communities to solve a wide range of environmental health problems. Among the Medical Geology described in this review are examples of both deficiency and toxicity of trace element exposure. Goiter is a widespread and potentially serious health problem caused by deficiency of iodine. In many locations the deficiency is attributable to low concentrations of iodine in the bedrock. Similarly, deficiency of selenium in the soil has been cited as the principal cause of juvenile cardiomyopathy and muscular abnormalities. Overexposure to arsenic is one of the most widespread Medical Geology problems affecting more than one hundred million people in Bangladesh, India, China, Europe, Africa and North and South America. The arsenic exposure is primarily due to naturally high levels in groundwater but combustion of mineralized coal has also caused arsenic poisoning. Dental and skeletal fluorosis also impacts the health of millions of people around the world and, like arsenic, is due to naturally high concentrations in drinking water and, to a lesser extent, coal combustion. Other Medical Geology issues described include geophagia, the deliberate ingestion of soil, exposure to radon, and ingestion of high concentrations of organic compounds in drinking water. Geosciences and biomedical/public health researchers are teaming to help mitigate these health problems.

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Muhongo, S., and N. Opiyo-Akech. "Geology and mineral resources of east Africa." Journal of African Earth Sciences 29, no. 2 (August 1999): 281–82. http://dx.doi.org/10.1016/s0899-5362(99)00097-4.

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7

Weakes, Michael. "Geology and mineral resources of West Africa." Journal of African Earth Sciences (1983) 6, no. 2 (January 1987): 243. http://dx.doi.org/10.1016/0899-5362(87)90065-0.

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8

DE BEER, J. H. "Geology of Johannesburg, Republic of South Africa." Environmental & Engineering Geoscience xxiii, no. 2 (May 1, 1986): 101–37. http://dx.doi.org/10.2113/gseegeosci.xxiii.2.101.

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9

Tarling, D. H. "Mesozoic and tertiary geology of Southern Africa." Earth-Science Reviews 23, no. 3 (May 1986): 226–27. http://dx.doi.org/10.1016/0012-8252(86)90020-6.

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10

Wright, J. B. "Mesozoic to Tertiary Geology of Southern Africa." Sedimentary Geology 49, no. 3-4 (October 1986): 296–97. http://dx.doi.org/10.1016/0037-0738(86)90048-5.

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11

de Wit, M. J., S. Bowring, R. Buchwaldt, F. Ö. Dudas, D. MacPhee, G. Tagne-Kamga, N. Dunn, A. M. Salet, and D. Nambatingar. "Geochemical reconnaissance of the Guéra and Ouaddaï Massifs in Chad: evolution of Proterozoic crust in the Central Sahara Shield." South African Journal of Geology 124, no. 2 (June 1, 2021): 353–82. http://dx.doi.org/10.25131/sajg.124.0048.

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Abstract In 1964, W.Q. Kennedy suggested that the crust of Saharan Africa is different from the rest of Africa. To date, the geologic evolution of this region remains obscure because the age and composition of crystalline basement are unknown across large sectors of the Sahara. Most of Africa comprises Archaean cratons surrounded by Palaeo- to Mesoproterozoic orogenic belts, which together constitute Africa’s three major shields (the Southern, Central and West African Shields), finally assembled along belts of Pan-African rocks. By contrast, central Saharan Africa (5.3x106 km2), an area just over half the size of Europe, is considered either as a Neoproterozoic region constructed of relatively juvenile crust (0.5 to 1.0 Ga), or as an older (North African) shield that was reactivated and re-stabilized during that time, a period commonly referred to as “Pan African”. Here, using U-Pb zircon age determinations and Nd isotopic data, we show that remote areas in Chad, part of the undated Darfur Plateau stretching across ¾ million km2 of the central Sahara, comprise an extensive Neoproterozoic crystalline basement of pre-tectonic gabbro-tonalite-granodiorite and predominantly post-tectonic alkali feldspar granites and syenites that intruded between ca. 550 to 1050 Ma. This basement is flanked along its western margin by a Neoproterozoic continental calc-alkaline magmatic arc coupled to a cryptic suture zone that can be traced for ~2400 km from Tibesti through western Darfur into Cameroon. We refer to this as the Central Saharan Belt. This, in a Gondwana framework, is part of a greater arc structure, which we here term the Great Central Gondwana Arc (GCGA). Inherited zircons and Nd isotopic ratios indicate the Neoproterozoic magmas in the central Sahara were predominantly derived from Mesoproterozoic continental lithosphere. Regional deformation between 613 to 623 Ma marks the onset of late alkaline granite magmatism that was widespread across a much larger area of North Africa until about 550 Ma. During this magmatism, the region was exhumed and eroded, leaving a regional peneplain on which early Palaeozoic (Lower-Middle Cambrian) siliciclastic sediments were subsequently deposited, as part of a thick and widespread cover that stretched across much of North Africa and the Arabian Peninsula. Detrital zircons in these cover sequences provide evidence that a substantial volume of detritus was derived from the central Sahara region, because these sequences include ‘Kibaran-age’ zircons (ca. 1000 Ma) for which a source terrain has hitherto been lacking. We propose that, in preference to calling the central Sahara a “ghost” or “meta” craton, it should be called the Central Sahara Shield.

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12

STEPHAN, TOBIAS, UWE KRONER, and ROLF L. ROMER. "The pre-orogenic detrital zircon record of the Peri-Gondwanan crust." Geological Magazine 156, no. 2 (February 8, 2018): 281–307. http://dx.doi.org/10.1017/s0016756818000031.

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AbstractWe present a statistical approach to data mining and quantitatively evaluating detrital age spectra for sedimentary provenance analyses and palaeogeographic reconstructions. Multidimensional scaling coupled with density-based clustering allows the objective identification of provenance end-member populations and sedimentary mixing processes for a composite crust. We compiled 58 601 detrital zircon U–Pb ages from 770 Precambrian to Lower Palaeozoic shelf sedimentary rocks from 160 publications and applied statistical provenance analysis for the Peri-Gondwanan crust north of Africa and the adjacent areas. We have filtered the dataset to reduce the age spectra to the provenance signal, and compared the signal with age patterns of potential source regions. In terms of provenance, our results reveal three distinct areas, namely the Avalonian, West African and East African–Arabian zircon provinces. Except for the Rheic Ocean separating the Avalonian Zircon Province from Gondwana, the statistical analysis provides no evidence for the existence of additional oceanic lithosphere. This implies a vast and contiguous Peri-Gondwanan shelf south of the Rheic Ocean that is supplied by two contrasting super-fan systems, reflected in the zircon provinces of West Africa and East Africa–Arabia.

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13

Koh, Sang-Mo, Gilljae Lee, Eui-Jun Kim, and Chung-Ryul Ryoo. "Geology and Mineralization of East Africa Rift System." Journal of the Mineralogical Society of Korea 26, no. 4 (December 31, 2013): 331–42. http://dx.doi.org/10.9727/jmsk.2013.26.4.331.

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14

CARTER, N. G. "Geology of Port Elizabeth, Republic of South Africa." Environmental & Engineering Geoscience xxiv, no. 4 (November 1, 1987): 441–67. http://dx.doi.org/10.2113/gseegeosci.xxiv.4.441.

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15

Berhe, S. M., and D. A. Rothery. "Interactive processing of satellite images for structural and lithological mapping in northeast Africa." Geological Magazine 123, no. 4 (July 1986): 393–403. http://dx.doi.org/10.1017/s0016756800033495.

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AbstractInteractive digital processing of multispectral satellite images (Landsat MSS) using principal components transformations and spatial filtering has clarified the position of continuous sutures linking apparently isolated Pan African (late Proterozoic) ophiolites. These have been field-checked and an arrangement of Pan African suture zones is proposed. Spatial filtering has also highlighted faults with various trends which can be related to the late Precambrian tectonics of the Horn of Africa region.

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16

Van Den Haute, Peter. "Branopunten in Het Geologisch Onoerzoek van Oostelijk Centraal-Afrika." Afrika Focus 1, no. 1-2 (January 12, 1985): 11–30. http://dx.doi.org/10.1163/2031356x-0010102003.

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Highlights in the geological research of central East Africa. The present paper offers a general view of the geological history of central East Africa. It is meant to inform persons involved in all kinds of African research about the physical background of this enormous continent. As the text is intended for people with no specific training in the earth sciences, an extensive introductory part has been dedicated to the general principles and methods of historical geology. The principle of superposition and the meaning of a major unconformity are shortly explained. Also the significance of fossils and of radiometric dating is elucidated with respect to the reconstruction of geological history. Further on a general outline is given of the great mountain belts of the African continent dating back from the earliest geological times (Precambrian), followed by a more detailed discussion of these belts in central East Africa. As to the younger structures of this region, attention has been focused on the large elongated furrow known as the East African rift. The major characteristics of this important feature in the earth's crust are described and its genesis is briefly discussed.

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17

Gheerbrant, E. "The oldest known proboscidean and the role of Africa in the radiation of modern orders of placentals." Bulletin of the Geological Society of Denmark 44 (February 28, 1998): 181–85. http://dx.doi.org/10.37570/bgsd-1998-44-12.

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Implications of the discovery of the oldest known proboscidean (Mammalia; Proboscidea) in the late Paleocene of Morocco, Phosphatherium escuilliei, are examined here in an overview of the paleobiogeographical framework of the African mammals. P. escuilliei evidences again the role of Africa in the radiation of modern orders of mammals and the early age of this radiation, which may be related to the extinctions at the K-T boundary. It supports definitely an African origin of the proboscideans, as for primates, hyracoideans, tubulidentates and macroscelideans. It examplifies a much higher antiquity of the African endemism of the placentals than was thought.

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18

N. Ekwueme, Barth. "Outstanding contribution to african geology a tribute to professor maarten de wit (1947 - 2022)." Global Journal of Geological Sciences 20, no. 1 (August 31, 2022): 93–95. http://dx.doi.org/10.4314/gjgs.v20i1.9.

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On the 15th April, 2022 Geology lost one of its finest brains and one of the most amiable geologists to my knowledge, Professor Maarten De Wit of South Africa. I first met amiable Maarten on July 3, 1990 while attending the 23rd Geocongress in Cape Town, South Africa. We became instant friends.

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19

Cohen, Alan. "Mr. Bain And Dr. Atherstone: South Africa's Pioneer Fossil Hunters." Earth Sciences History 19, no. 2 (January 1, 2000): 175–91. http://dx.doi.org/10.17704/eshi.19.2.hm71m0h265363j36.

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Although a few explorers had reported the finding of fossils in South Africa during the eighteenth century, interested amateurs made the first important collections of fossils during the 1830s. Many new species were discovered and sent back to London, for further study by the newly emerging class there of professional palaeontologists such as Richard Owen (1804-1892) of the British Museum's Natural History Department. As a result of a few pioneers like Andrew Geddes Bain (1797-1864) and William Guybon Atherstone (1814-1898), the study of South African geology and palaeontology was placed on a firm footing by the 1860s. Owen publicly acknowledged their contributions to these new sciences in 1876 in his monumental study of the fossil reptiles of South Africa.1

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20

Orr, Theresa J., Eric M. Roberts, Michael I. Bird, Cassy Mtelela, Patrick M. O'Connor, and Nancy J. Stevens. "Paleosol-derived paleoclimate and paleoenvironment reconstruction of the Rukwa Rift Basin, Tanzania: implications for faunal dispersal in the Miocene–Pliocene." Journal of Sedimentary Research 93, no. 5 (May 31, 2023): 309–26. http://dx.doi.org/10.2110/jsr.2022.015.

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ABSTRACT The East African Rift System records a key interval in the evolution of modern African ecosystems, documenting significant floral changes and faunal dispersals in the context of environmental shifts. To date, Miocene-to-Pliocene data from eastern Africa have been derived primarily from richly fossiliferous rift basins along the far north of the Eastern Branch of the rift, with more limited windows emerging from the Malawi Rift and more recently, coastal Mozambique. Here, we present the first quantitative paleoclimate data for the Miocene–Pliocene transition from the Western Branch of the East African Rift System, based on analyses of paleosols from the Rukwa Rift Basin. Paleosols derived from the fossiliferous late Miocene–early Pliocene lower Lake Beds succession in southwestern Tanzania preserve a shallow lacustrine setting grading into a system of alluvial fans and braided rivers with abundant floodplain deposits. Paleoclimate reconstructions using bulk geochemistry and clay mineralogy reveal a highly seasonal, semiarid, mesic climate during the late Miocene, with increased moisture availability in the early Pliocene resulting in a shift to subhumid conditions. Stable-carbon-isotope composition of pedogenic carbonates document a woodland/bushland/shrubland paleoenvironment across the Miocene–Pliocene transition. Results support the presence of Pliocene subhumid to humid habitats, dominated by woody vegetation offering shade, food, and water for faunal dispersal along an inland corridor connecting northern segments of the East African Rift System with southern Africa.

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Permana, Aa. "Pelayanan Pengunjung Disabilitas pada Museum Geologi dan Museum Konferensi Asia Afrika di Kota Bandung." Tourism Scientific Journal 9, no. 2 (June 11, 2024): 210–20. http://dx.doi.org/10.32659/tsj.v9i2.353.

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This study is entitled "Disability Visitor Service at the Museum of Geology and Museum of the Asia Africa Conference in the Bandung City". This study seeks to find a discussion of museum services for persons with disabilities that substantively refer to the service quality concept revealed by Zeinthaml in 2006 consisting of (1) Tangibles, (2) Empathy, (3) Responsiveness, (4) Reliable and (5) Assurance, and performed at the Museum of Geology and the Museum of Asia Africa. This research uses a qualitative method approach. A qualitative approach is considered by researchers to be very appropriate in providing a holistic picture of the existing reality data. Data collection was performed using observation techniques, in- depth interviews, and documentation. Data analyzed was using the stages described by Miles and Huberman (1992: 16). Based on research, a conclusion can be drawn that both museums have all aspect studied for disabilities tourists. Broadly speaking, the Museum of Geology already has infrastructure and services that prepared for disabilities tourists, meanwhile the Museum of Asia Africa still has a variety of obstacles and minimal infrastructure will be aimed for disabilities tourists with some rules procedure and condition.

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Haarhoff, J., and L. Korf. "ABA Brink: Pioneer of engineering geology in South Africa." Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 26, no. 2 (September 21, 2007): 139–50. http://dx.doi.org/10.4102/satnt.v26i2.130.

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Anthony Berrange Antill Brink – beter bekend as ABA Brink aan die lesers van sy boeke, of net Tony vir sy groot aantal kennisse en vriende – was met sy geboorte in 1927 die derde en laaste kind van Rex Brink en Georgina Antill

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Morley, C. K., S. M. Cunningham, R. M. Harper, and William A. Wescott. "Geology and geophysics of the Rukwa Rift, East Africa." Tectonics 11, no. 1 (February 1992): 69–81. http://dx.doi.org/10.1029/91tc02102.

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Crawford, R. "Petroleum Geology of Africa: New Themes and Developing Technologies." Marine and Petroleum Geology 21, no. 5 (May 2004): 639. http://dx.doi.org/10.1016/j.marpetgeo.2004.03.002.

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Ramsay, P. J. "Marine geology of the Sodwana Bay shelf, southeast Africa." Marine Geology 120, no. 3-4 (September 1994): 225–47. http://dx.doi.org/10.1016/0025-3227(94)90060-4.

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Keeley, M. L., and M. S. Massoud. "Tectonic controls on the petroleum geology of NE Africa." Geological Society, London, Special Publications 132, no. 1 (1998): 265–81. http://dx.doi.org/10.1144/gsl.sp.1998.132.01.15.

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27

LIU, Jian-Ping, Xiao-hua PAN, Jun MA, Zuo-ji TIAN, Yong-jin CHEN, and Lun-kun WAN. "Petroleum geology and resources in West Africa: An overview." Petroleum Exploration and Development 35, no. 3 (June 2008): 378–84. http://dx.doi.org/10.1016/s1876-3804(08)60086-5.

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McCourt, S., R. A. Armstrong, G. H. Grantham, and R. J. Thomas. "Geology and evolution of the Natal belt, South Africa." Journal of African Earth Sciences 46, no. 1-2 (September 2006): 71–92. http://dx.doi.org/10.1016/j.jafrearsci.2006.01.013.

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29

Nzubechi Akubueze, Christian. "Democracy's Discontent and the Resurgence of Coups in West Africa: Implications for Africa." African Journal of Law, Political Research and Administration 7, no. 1 (February 14, 2024): 14–24. http://dx.doi.org/10.52589/ajlpra-unwjtjen.

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The resurgence of military coups in African politics poses a challenge for democracy and it highlights the fragility of democratization in Africa. Going by the recent coup waves, democracy appears to be in a very fragile state in Africa. Africa for a very long time has enjoyed relative stability in its democratization process. However, this long period of stability is being challenged again as there have already been five successful overthrows of democratically elected governments in Chad, Mali, Guinea, Sudan, Burkina Faso, and Niger between 2021 and 2023 in addition to the unsuccessful attacks. It is equally worth noting that the recent coup waves in Africa have been dominated by West African states: Niger, Mali, Burkina Faso, and Guinea. Unlike in the past when citizens greeted attacks on democratically elected governments with discontent and disapproval, the recent coups have for so many reasons been met with support and acceptance by citizens through celebrations on the streets and supportive messages on social media. This paper therefore seeks to examine democracy’s discontent and the resurgence of coups in West Africa to identify its implications for Africa. The study relied essentially on qualitative data predicated on secondary data. The paper adopted populism as its framework of analysis. The paper revealed that the popular support for the recent coup waves stems from citizens' dissatisfaction with the performance of democracy and democratic leadership. The study recommended, amongst other things, that democratic institutions should be reformed and strengthened, good governance should be promoted by African leaders, and maximum attention should be paid to the welfare and concerns of the military to strengthen professionalism.

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Muir, R. A., E. M. Bordy, J. S. V. Reddering, and J. H. A. Viljoen. "Lithostratigraphy of the Enon Formation (Uitenhage Group), South Africa." South African Journal of Geology 120, no. 2 (June 1, 2017): 273–80. http://dx.doi.org/10.25131/gssajg.120.2.273.

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Abstract The Uitenhage Group represents the earliest deposits that filled Mesozoic rift basins in the southern Cape of South Africa during the fragmentation of the supercontinent Gondwana. The sedimentology of the Enon Formation records the development of alluvial systems that drained the region since the onset of Gondwanan rifting, and therefore plays an important role in our understanding of early landscape evolution along the southern African continental margin. The mostly coarse conglomeratic unit was deposited continuously in actively subsiding, but separated, rift basins. As a result, the deposits are diachronous between basins and display highly varied thicknesses of up to well over 2000 m.

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Hopley, Philip J., Graham P. Weedon, Chris M. Brierley, Christopher Thrasivoulou, Andy I. R. Herries, Ada Dinckal, David A. Richards, et al. "Orbital precession modulates interannual rainfall variability, as recorded in an Early Pleistocene speleothem." Geology 46, no. 8 (July 12, 2018): 731–34. http://dx.doi.org/10.1130/g45019.1.

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Abstract Interannual variability of African rainfall impacts local and global communities, but its past behavior and response in future climate projections are poorly understood. This is primarily due to short instrumental records and a lack of long high-resolution palaeoclimate proxy records. Here we present an annually resolved 91,000 year Early Pleistocene record of hydroclimate from the early hominin-bearing Makapansgat Valley, South Africa. Changes in speleothem annual band thickness are dominated by precession over four consecutive orbital cycles with strong millennial-scale periodicity. The frequency of interannual variability (2.0–6.5 yr oscillations) does not change systematically, yet its amplitude is modulated by the orbital forcing. These long-term characteristics of interannual variability are reproduced with transient climate model simulations of water balance for South Africa from the Late Pleistocene to Recent. Based on these results, we suggest that the frequency of interannual variations in southern African rainfall is likely to be stable under anthropogenic warming, but that the size of year-to-year variations may increase. We see an orbitally forced increase in the amplitude of interannual climate variability between 1.8 Ma and 1.7 Ma coincident with the first evidence for the Acheulean stone tool technology.

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WARREN, A. A., R. DAMIANI, and A. M. YATES. "The South African stereospondyl Lydekkerina huxleyi (Tetrapoda, Temnospondyli) from the Lower Triassic of Australia." Geological Magazine 143, no. 6 (September 4, 2006): 877–86. http://dx.doi.org/10.1017/s0016756806002524.

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The first tetrapod fossil from the Rewan Formation of the Galilee Basin, central Queensland, Australia, is identified as Lydekkerina huxleyi, a stereospondyl found elsewhere only in the Lystrosaurus Assemblage Zone of South Africa. Apomorphies shared with L. huxleyi are: anterior palatal vacuity with anterodorsal projections from its posterior margin; ventral surface of skull roof with series of thickened ridges (condition unknown in other lydekkerinids); and vomerine shagreen present (possible autapomorphic reversal). Restudy of the only other Australian lydekkerinid, Chomatobatrachus halei, shows it to be distinct from L. huxleyi. The Rewan Formation, undifferentiated in the Galilee Basin, can be correlated with the Rewan Group of the Bowen Basin, and to the early part of the Lystrosaurus Assemblage Zone of the Karoo Basin, South Africa, which are of Griesbachian age. Varying palaeoenvironments may contribute to the contrasting nature of the Australian and South African faunas.

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Bosellini, Alfonso. "East Africa continental margins." Geology 14, no. 1 (1986): 76. http://dx.doi.org/10.1130/0091-7613(1986)14<76:eacm>2.0.co;2.

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34

Rogers, Nick. "Magmatism in extensional Africa." Journal of Structural Geology 14, no. 10 (November 1992): 1278. http://dx.doi.org/10.1016/0191-8141(92)90078-b.

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35

Von Knorring, O., and E. Condliffe. "Mineralized pegmatites in Africa." Geological Journal 22, S2 (1987): 253–70. http://dx.doi.org/10.1002/gj.3350220619.

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36

Jones, Robert W. "Africa Comes to Arizona." Rocks & Minerals 77, no. 1 (February 2002): 60–61. http://dx.doi.org/10.1080/00357529.2002.9926659.

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Gray, Michael. "Colored Gemstones of Africa." Rocks & Minerals 77, no. 2 (April 2002): 108–19. http://dx.doi.org/10.1080/00357529.2002.9926666.

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Attoh, Kodjopa. "High‐Pressure Granulite Facies Metamorphism in the Pan‐African Dahomeyide Orogen, West Africa." Journal of Geology 106, no. 2 (March 1998): 236–46. http://dx.doi.org/10.1086/516019.

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39

Villeneuve, Michel, and Camille Rossignol. "Linking the Neoproterozoic to Early Paleozoic Belts Bordering the West African and Amazonian Cratons: Review and New Hypothesis." Minerals 14, no. 1 (December 30, 2023): 48. http://dx.doi.org/10.3390/min14010048.

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Correlations between the Neoproterozoic belts surrounding the West African Craton and northern Brazilian cratons have long been a subject of interest and controversies. Due to the splitting of African and South American continents by the Atlantic oceanic domains, no direct links are preserved, requiring relying on various geological or geophysical characteristics to propose such correlations. In addition to the opening of the Atlantic oceanic domains, another difficulty arises from the covering of northern Brazilian belts by upper Paleozoic and Mesozoic basins, making these correlations speculative. Here, we propose new correlations based on the comparison between African and Brazilian belts. Recently, new geochronological and geodynamical data obtained in West Africa have evidenced four orogens in the Neoproterozoic belts of the western margin of the West Africa Craton, while the belts on the eastern side underwent only one orogeny. Similarities with the Pan-African I (900–650 Ma) and with the Pan-African II (650–480 Ma) orogenic events have been evidenced in the western Brazilian belts (Araguay and Paraguay). The first two orogens on the western margin (Pan-African I and Pan-African II) can thus be extended to the western Brazilian belts and can be considered as parts of a single geodynamic system running from the Mauritania to the Paraguay including the “Gurupi rift” as an aulacogen connected to the NNW-SSE Panafrican I and II oceanic domains. Consequently, the eastern Brazilian belt should rather be linked the Eastern Trans-Saharan belts.

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Cooper, G. R. J. "An improved terracing algorithm for potential-field data." GEOPHYSICS 85, no. 5 (September 1, 2020): G109—G113. http://dx.doi.org/10.1190/geo2019-0129.1.

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Although the boundaries between geologic units with different physical properties are usually quite distinct, the potential-field anomalies associated with them are relatively smooth, particularly for deeper bodies. The terracing filter has been introduced to sharpen anomaly edges and to produce regions of constant amplitude between them, mimicking geologic units on a geologic map. The boundaries between the pseudogeologic units are defined by the zero contour of the Laplacian function. Unfortunately, this can result in the domains of terraced anomalies extending far from the original location of the causative body, producing an image that poorly represents the geology. I have determined that the use of the mathematical shape index of the anomalies, rather than their Laplacian, produces a much more geologically realistic result. The effect can be controlled as desired using a threshold parameter. I evaluate the benefits of the method on gravity and magnetic data from southern Africa.

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Cawthra, H. C., E. W. Bergh, E. A. Wiles, and J. S. Compton. "Late Quaternary deep marine sediment records off southern Africa." South African Journal of Geology 124, no. 4 (December 1, 2021): 1007–32. http://dx.doi.org/10.25131/sajg.124.0059.

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Abstract High-resolution mapping, sampling and analysis of upper Quaternary southern African continental margin sediments recovered from beyond the Last Glacial Maximum shoreline (>130 m water depth) have expanded our understanding of how marine and terrestrial records are linked over glacial-interglacial climatic cycles. This paper synthesises data currently available from the deep seafloor around southern Africa and, specifically, core sites that demonstrate terrestrial sedimentological connectivity. Several proxies and case studies reveal the evolution of depositional systems, palaeoceanography and palaeoclimate over the last 191 kyr. Hydroacoustic mapping and investigations of submarine canyons have been carried out primarily on the eastern and southwestern margins, while palaeoceanographic productivity and microfossil assemblages have been applied most extensively on the western marine and southern Agulhas Bank. Studies on the western margin indicate that enhanced productivity, less oxygenated bottom waters and reduced marine faunal diversity in the transition to glacial periods, while glacial terminations are associated with reduced productivity and more oxygenated bottom waters. These changes, linked to palaeoceanography and late Quaternary sea-level fluctuations, influence the sedimentary record and sedimentation rates. On the eastern margin, sediment fluxes applied as proxies for rainfall offshore of the Great Kei, Umzimvubu, Limpopo and Zambezi rivers indicate that the southern African climate responds to changes in orbitally-modulated insolation and in particular, to the ~23 kyr precessional cycle, where the proxy records keep pace with this and then diverge at ~80 to 70 kyr. Since the penultimate glacial (Marine Isotope Stage/MIS 6), more humid conditions observed in southern Africa, as the Northern Hemisphere entered phases of rapid cooling, were potentially driven by a combination of warming in the Agulhas Current and shifts of the subtropical anticyclones. Broadly, the sedimentary records reviewed suggest fluctuations in climate and oceanographic circulation that are strongly correlated with the global benthic δ18O record, suggesting sensitivity to high-latitude forcing, and a strong influence of late Quaternary glacial-interglacial cycles despite these marine sites being far-removed from terrestrial environments.

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Andersen, T., G. A. Botha, and M. A. Elburg. "A late Mesozoic – early Cenozoic sedimentary recycling system on the Gondwana rifted margin of southeast Africa." South African Journal of Geology 123, no. 3 (September 1, 2020): 343–56. http://dx.doi.org/10.25131/sajg.123.0023.

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Abstract Detrital zircons in late Cretaceous – Palaeogene, calcareous sandstone and conglomerate deposited in continental basins on the southeastern African margin after the breakup of Gondwana have characteristic combinations of age and epsilon-Hf that indicate an origin by recycling of Palaeoproterozoic (Waterberg, Soutpansberg and Pretoria groups) and Phanerozoic (Karoo Supergroup) cover successions. The latter is dominant in the south and east (Boane, Mahosi, Chilojo Cliffs), and the Palaeoproterozoic sources in the northwest (Pafuri, Wright’s Tower, Masisi). This recycling and mixing regime was restricted to late Mesozoic and Palaeogene time in northeastern South Africa and adjoining parts of Mozambique and Zimbabwe. Detrital zircon distribution patterns in these deposits reflect the denudation history of the southern African continental surface after breakup of the Gondwana supercontinent.

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de Bonis, Louis, Stephane Peigne, Andossa Likius, Hassane T. Makaye, Michel Brunet, and Patrick Vignaud. "First occurrence of the ‘hunting hyena’ Chasmaporthetes in the Late Miocene fossil bearing localities of Toros Menalla, Chad (Africa)." Bulletin de la Société Géologique de France 178, no. 4 (July 1, 2007): 317–26. http://dx.doi.org/10.2113/gssgfbull.178.4.317.

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Abstract Late Miocene localities of Toros Menalla (Chad) have yielded many bones of fossil vertebrates with a lot of mammalian remains. Among the mammals, there are several Carnivora taxa, especially hyenids. The family Hyaenidae is very well developed during this period with classical bone crusher species but also with flesh eater taxa which are called hunting hyenas. The genus Chasmaporthetes is one of these taxa. It was described from North America, Asia, Euro-pa and South Africa but it is recorded for the first time in central Africa. The Chadian specimens are close to the South African species C. australis (Hendey, 1974) but differs through some morphological and metrical details. C. australis is a huge hunting hyena, a little bigger than the extant species Crocuta crocuta, the spotted hyena. An isolated premolar recorded in the locality Sahabi (Libya) belongs probably to the same group. The spreading of this large hunting species is probably correlated with the abundance of large ungulates in the local faunas.

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ROSE, EDWARD P. F. "MILITARY GEOLOGY: AN AMERICAN TERM OF WORLD WAR I RE-DEFINED FOR THE BRITISH ARMY AT THE END OF WORLD WAR II." Earth Sciences History 42, no. 2 (July 1, 2023): 291–326. http://dx.doi.org/10.17704/1944-6187-42.2.291.

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ABSTRACT The term ‘military geology’, translated from German after earlier use in French and Spanish publications, entered the English language via American publications from 1917 onwards, initially after the USA entered World War I. It was widely used in the USA and, in direct or indirect translation, in several European countries additional to Germany and Austria thereafter, but not in the United Kingdom—although military applications of geology had been perceived and utilized by the British Army for much of the previous century. However, the term was used and its scope defined on the basis of operational experience at a meeting in Brussels on 28 February to 1 March 1945 as World War II drew to an end, a meeting seemingly unique for the War in that it comprised five ‘British’ geologist officers of field rank: the South African Major Gordon Lyall Paver, English Major Frederick William Shotton, Australian-born but Canadian-educated English Major John Leonard Farrington, English Squadron Leader John Francis Kirkaldy, and Welsh Major David Ronald Arthur Ponsford. Their purpose was to review wartime use of ‘military geology’ in the British Army, and to make recommendations for a more efficient British military geological service in the future, especially in the Far East after the war in Europe entered its final phase. The meeting generated a four-page closely-typed unpublished ‘Memorandum: Military geology in the British services’ (now preserved in England in the Lapworth Museum at the University of Birmingham and in The National Archives, Kew, near London). This included a very brief summary of the British Army’s deployment of geologists within western Europe, East Africa, the Middle East, North Africa and the Mediterranean region, and India. Those present brought together long experience from all these campaign areas except India (and the Far East in general). That deficiency was made good later in the year, on 7 December 1945, when Eric J. Bradshaw, Superintending Geologist of the Strategic Branch of the Geological Survey of India, completed an 81-page typed unpublished ‘Military geology: Memorandum of post-war policy’ (accessible in England at Birmingham, at Kew, and at the British Geological Survey, Keyworth). This with its 23 pages of appendices records details of wartime work in India and discussions held by the author there and in the United Kingdom following the end of hostilities in Europe on 8 May 1945. It re-defines the scope of ‘military geology’ for British armed forces in terms of water (resources, floods and drainage), stone and miscellaneous mineral resources, soils, engineering projects (reconnaissance, stability and excavations), terrain, ‘photo-geology’ and several miscellaneous applications. The memorandum proposed a grandiose organization of 151 geologist officers plus ancillary staff for British military geology postwar. That organizational scheme was not adopted—but by 1945 the term ‘military geology’ had clearly extended from American to significant British use.

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Lézine, Anne-Marie, Franck Bassinot, and Jean-Yves Peterschmitt. "Orbitally-induced changes of the Atlantic and Indian monsoons over the past 20,000 years: New insights based on the comparison of continental and marine records." Bulletin de la Société Géologique de France 185, no. 1 (January 1, 2014): 3–12. http://dx.doi.org/10.2113/gssgfbull.185.1.3.

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Abstract Variations of Atlantic and Indian monsoon systems since the last glacial period are investigated by comparing eolian fluxes from two marine cores (ODP site 658 off western Africa and core 74KL off the Arabian peninsula) with 2147 hydrological records (lacustrine, palustrine, spring and fluvial, arid) gathered over a large continental area extending between 10 and 30°N across Africa, Arabia and western India. We show that the hydrological response to the Holocene humid phase in the northern tropics strongly differs from a region to another. The humid period is significantly shorter in the Arabian peninsula and the horn of Africa compared to northern Africa even though its maximum is contemporaneous (11,000–7,000 cal yr BP). Western India displays a specific hydrological signal characterized by the importance of well-developed fluvial systems from the Himalayas and the paucity of lakes compared to the other regions. In western India, the humid peak is shifted toward the mid Holocene (8,000–6,000 cal yr BP). Both marine records show a peak between ~ 11,000 and 7,000 cal yr BP for the Holocene humid period, in good accordance with African-Arabian records. However, while continental hydrological data suggest that the onset and termination of this humid period might have been relatively progressive, the marine windborne records indicate abrupt transitions, somewhat out-of-phase with continental evidence (e.g. abrupt decrease of aeolian proxies as early as ~ 15,000 cal yr BP). Discrepancies between marine and continental likely result from the fact that aeolian fluxes at a given marine location do not simply record monsoon-related changes of humidity over the adjacent continental sources but could be affected also by changes of the source area (e.g., emersion of the Arabo-Persian gulf associated to the glacial, low sea-level stand), and changes in wind intensity and/or direction.

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Ben-Avraham, Zvi, George Smith, Moshe Reshef, and Eric Jungslager. "Gas hydrate and mud volcanoes on the southwest African continental margin off South Africa." Geology 30, no. 10 (2002): 927. http://dx.doi.org/10.1130/0091-7613(2002)030<0927:ghamvo>2.0.co;2.

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Mwanzia, Dorothy Kanini, Peace Zowa, Dennis Achoki, Ozotta Ogochukwu, Chioma Onwumelu, and Antony Hiuhu Mwangi. "Student Zone." Leading Edge 40, no. 1 (January 2021): 74–75. http://dx.doi.org/10.1190/tle40010074.1.

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More than 80 young professionals and students from around the world attended the 1st Virtual African Young Professionals and Students Geoscience Week, which took place 21–26 September 2020. Participants were from Argentina, Brazil, Congo, Germany, Ghana, Indonesia, Kenya, Malawi, Mexico, Nigeria, Rwanda, South Africa, Tanzania, Uganda, Ukraine, the United States, and Zimbabwe. Figure 1 shows a distribution map of the represented locations. A total of 12 speakers presented on a variety of interesting topics throughout the week.

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Ouedraogo, Issoufou, and Marnik Vanclooster. "Challenges of groundwater pollution and management in transboundary basins at the African scale." Proceedings of the International Association of Hydrological Sciences 384 (November 16, 2021): 69–74. http://dx.doi.org/10.5194/piahs-384-69-2021.

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Abstract. We address the significant knowledge gap for groundwater pollution in Africa methods by assessing groundwater pollution risk at the African scale. To do so, we compiled the most recent continental-scale information on soil, land use, geology, hydrogeology, and topography in a Geographical Information System at the resolution of 15 × 15 km and the 1:60 000 000 scale. We produced a vulnerability map by using the generic DRASTIC vulnerability indicator. This map revealed that groundwater is highly vulnerable in Central and West Africa groundwater basins, where the water table is shallow. In addition, very low vulnerability classes are found in the large sedimentary basins of Africa deserts where groundwater is situated in very deep aquifers. The generic groundwater pollution risk map is obtained by overlaying the DRASTIC vulnerability indicator with current land use. The northern, central, and western parts of the African continent are dominated by high vulnerability classes and very strongly related to water table depths and the development of agricultural activities. Given the availability of data, we concentrate first on nitrate vulnerability mapping. To this end, groundwater nitrate contamination data are compiled in literature using meta-analysis technic and used to calibrate as well linear and nonlinear statistical models; the latter performing much better as compared to simple linear statistical models. This study will help to raise awareness of the manager's International Basin Authorities or Transboundary Basin Organizations in Africa and in particular on transboundary groundwater pollution issues.

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Sabato Ceraldi, Teresa, Richard Hodgkinson, and Guillaume Backé. "The petroleum geology of the West Africa margin: an introduction." Geological Society, London, Special Publications 438, no. 1 (August 12, 2016): 1–6. http://dx.doi.org/10.1144/sp438.11.

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Harande, Yahya Ibrahim. "Bibliometric Analysis of Economic Geology Literature from Africa 1993-1996." Science & Technology Libraries 20, no. 4 (July 2001): 45–54. http://dx.doi.org/10.1300/j122v20n04_06.

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Journal articles on the topic 'Geology Africa'

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