Matches in SemOpenAlex for { <https://semopenalex.org/work/W2892207910> ?p ?o ?g. }
Showing items 1 to 80 of
80
with 100 items per page.
- W2892207910 abstract "The Postmasburg Manganese Field (PMF), located in the Northern Cape Province of South Africa, once represented one of the largest sources of manganese ore worldwide. However, the discovery of the giant manganese deposits of the Kalahari Manganese Field (KMF) led to the gradual decline in manganese mining activity in the PMF. Two belts of manganese ore deposits have been distinguished in the PMF, namely the Western Belt of ferruginous manganese ores and the Eastern Belt of siliceous manganese ores. Prevailing models of ore formation in these two belts invoke karstification of manganese-rich dolomites and residual accumulation of manganese wad which later underwent diagenetic and low-grade metamorphic processes. For the most part, the role of hydrothermal processes in ore formation and metasomatic alteration is not addressed. The identification of an abundance of common and some rare Al-, Na-, K- and Ba-bearing minerals, particularly aegirine, albite, microcline, banalsite, serandite-pectolite, paragonite and natrolite in the PMF ores studied in this thesis, is indicative of the influence of hydrothermal activity. Enrichments in Na, K and/or Ba in the ores are generally on a percentage level for the majority of samples analysed through bulk-rock techniques. The discovery of a Ba-Mn arsenate/vanadate similar to gamagarite may also indicate that the hydrothermal fluid affecting the ores was not only alkali-rich but also probably contained some As and V. The fluid was likely to be oxidized and alkaline in nature and is thought to have been a mature basinal brine. Various replacement textures, particularly of Na- and Krich minerals by Ba-bearing phases, suggest sequential deposition of gangue as well as oreminerals from the hydrothermal fluid, with Ba phases being deposited at a later stage. The stratigraphic variability of the studied ores and the deviation of their character from the pigeon-hole-type classification of ferruginous and siliceous ores in the literature, suggests that a re-evaluation of genetic models is warranted. The discovery of hydrothermallydeposited alkali-rich assemblages in the PMF and KMF provides grounding for further investigation into a possible regional-scale hydrothermal event at least re-constituting the ores. Some shortcomings in previous works include disregard for the highly variable nature of the PMF deposits, the effects of hydrothermal activity of the ores and the existence of stratigraphic discrepancies. This study provides a single, broad model for the development of all manganese deposits of the PMF. The source of metals is attributed to all formations that stratigraphically overly the Reivilo Formation of the Campbellrand Subgroup (including the Reivilo Formation itself). The main process by which metals are accumulated is attributed to karstification of the dolomites. The interaction of oxidized, alkaline brines with the ores is considered and the overlying Asbestos Hills Subgroup BIF is suggested as a potential source of alkali metals." @default.
- W2892207910 created "2018-09-27" @default.
- W2892207910 creator A5090054787 @default.
- W2892207910 date "2014-01-01" @default.
- W2892207910 modified "2023-09-23" @default.
- W2892207910 title "Genesis of karst-hosted manganese ores of the Postmasburg Manganese Field, South Africa with emphasis on evidence for hydrothermal processes" @default.
- W2892207910 hasPublicationYear "2014" @default.
- W2892207910 type Work @default.
- W2892207910 sameAs 2892207910 @default.
- W2892207910 citedByCount "1" @default.
- W2892207910 countsByYear W28922079102015 @default.
- W2892207910 crossrefType "journal-article" @default.
- W2892207910 hasAuthorship W2892207910A5090054787 @default.
- W2892207910 hasConcept C127313418 @default.
- W2892207910 hasConcept C130452526 @default.
- W2892207910 hasConcept C151730666 @default.
- W2892207910 hasConcept C156622251 @default.
- W2892207910 hasConcept C165205528 @default.
- W2892207910 hasConcept C167919410 @default.
- W2892207910 hasConcept C17409809 @default.
- W2892207910 hasConcept C178790620 @default.
- W2892207910 hasConcept C185592680 @default.
- W2892207910 hasConcept C195845463 @default.
- W2892207910 hasConcept C199289684 @default.
- W2892207910 hasConcept C2775859737 @default.
- W2892207910 hasConcept C2776062231 @default.
- W2892207910 hasConcept C2776432453 @default.
- W2892207910 hasConcept C2776597492 @default.
- W2892207910 hasConcept C2777344214 @default.
- W2892207910 hasConcept C2779870107 @default.
- W2892207910 hasConcept C2780191791 @default.
- W2892207910 hasConcept C528890316 @default.
- W2892207910 hasConcept C67236022 @default.
- W2892207910 hasConceptScore W2892207910C127313418 @default.
- W2892207910 hasConceptScore W2892207910C130452526 @default.
- W2892207910 hasConceptScore W2892207910C151730666 @default.
- W2892207910 hasConceptScore W2892207910C156622251 @default.
- W2892207910 hasConceptScore W2892207910C165205528 @default.
- W2892207910 hasConceptScore W2892207910C167919410 @default.
- W2892207910 hasConceptScore W2892207910C17409809 @default.
- W2892207910 hasConceptScore W2892207910C178790620 @default.
- W2892207910 hasConceptScore W2892207910C185592680 @default.
- W2892207910 hasConceptScore W2892207910C195845463 @default.
- W2892207910 hasConceptScore W2892207910C199289684 @default.
- W2892207910 hasConceptScore W2892207910C2775859737 @default.
- W2892207910 hasConceptScore W2892207910C2776062231 @default.
- W2892207910 hasConceptScore W2892207910C2776432453 @default.
- W2892207910 hasConceptScore W2892207910C2776597492 @default.
- W2892207910 hasConceptScore W2892207910C2777344214 @default.
- W2892207910 hasConceptScore W2892207910C2779870107 @default.
- W2892207910 hasConceptScore W2892207910C2780191791 @default.
- W2892207910 hasConceptScore W2892207910C528890316 @default.
- W2892207910 hasConceptScore W2892207910C67236022 @default.
- W2892207910 hasLocation W28922079101 @default.
- W2892207910 hasOpenAccess W2892207910 @default.
- W2892207910 hasPrimaryLocation W28922079101 @default.
- W2892207910 hasRelatedWork W1971611052 @default.
- W2892207910 hasRelatedWork W1984466054 @default.
- W2892207910 hasRelatedWork W2006155482 @default.
- W2892207910 hasRelatedWork W2017344213 @default.
- W2892207910 hasRelatedWork W2117426007 @default.
- W2892207910 hasRelatedWork W2223021372 @default.
- W2892207910 hasRelatedWork W2316585823 @default.
- W2892207910 hasRelatedWork W2319525270 @default.
- W2892207910 hasRelatedWork W2348817143 @default.
- W2892207910 hasRelatedWork W2370795607 @default.
- W2892207910 hasRelatedWork W2650697696 @default.
- W2892207910 hasRelatedWork W2888997492 @default.
- W2892207910 hasRelatedWork W2954836989 @default.
- W2892207910 hasRelatedWork W2955347357 @default.
- W2892207910 hasRelatedWork W2957226462 @default.
- W2892207910 hasRelatedWork W2971604899 @default.
- W2892207910 hasRelatedWork W2981156327 @default.
- W2892207910 hasRelatedWork W3049267377 @default.
- W2892207910 hasRelatedWork W3134566592 @default.
- W2892207910 hasRelatedWork W2127531434 @default.
- W2892207910 isParatext "false" @default.
- W2892207910 isRetracted "false" @default.
- W2892207910 magId "2892207910" @default.
- W2892207910 workType "article" @default.