Uranium mineralization in the Karoo Basin, South Africa

Turner, Brian R.

doi:10.2113/gsecongeo.80.2.256

Cited by 19 publications

(14 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Abrahamskraal from Stear (1980Stear ( , 1985, Jordaan (1981), Turner (1981), Rubidge (1988), and Cole and Wipplinger (1991); Teekloof from Stear (1980Stear ( , 1985, Turner (1981), and Cole and Wipplinger (in preparation). Initial progradation of fluvial deposits over a delta, followed by decreasing fluvial energy as a result of denudation of the source area (Turner, 1985). The fluvial channels range from low-to high-sinuosity (Stear, 1980(Stear, , 1985 and the sandstones cluster into packages (Stear, 1980;Cole and Wipplinger, 1991).…”

Section: Karoo Sequencementioning

confidence: 99%

“…8B, part VI), the Waterford delta is succeeded by the fluvial channel and flood basin deposits of the Abrahamskraal and Teekloof Formations. The channels, which contain uranium (Ryan and Whitfield, 1979), range from low-to high-sinuosity, and the fluvial energy decreases upward due to denudation of the source area (Turner, 1985). In the southeast (Fig.…”

Section: Tap-tapinocephalus Cis-cistecephalus Dap-daptocephalus Lymentioning

confidence: 99%

See 1 more Smart Citation

Southern Africa: Karoo Basin and Cape Fold Belt

Veevers¹,

Cole²,

Cowan³

1994

Geological Society of America Memoirs

106

View full text Add to dashboard Cite

Three basement trends, defined by the 1.0-0.5 Ga foldbelts of weak crust that wrap around the 1 Ga Namaqua-Natal Belt and >2.5 Ga Kaapvaal Province, provide a tub-shaped template that was impressed on succeeding structures up to the Cretaceous breakup of Pangea along the present divergent margins. The pattern is reprinted during the Ordovician-Devonian deposition of the Cape Supergroup in grabens on the northwest and northeast linked by an east-west depositional axis and during the Permian and Triassic development of the Cape Fold Belt along the eastwest trend linked with intermittent uplifts to the northwest (Atlantic upland) at a syntaxis around Cape Town and to the northeast (Eastern upland) at a syntaxis in the (restored) Falkland Islands.The inception of the Karoo (Gondwanan) Sequence in the latest Carboniferous (290 Ma) reflected the Gondwanaland-wide relaxation of the Pangean platform in sags (Karoo terrain) and rifts (Zambezian terrain). The first appearance of tuffs from a convergent arc in the Sakmarian (ca. 277 Ma) marked the onset of a foreland basin. Material derived from the south included a small component of mainly rhyodacitic tuff which persisted to the end of Beaufort deposition, when the presumed southern magmatic arc became extinct. Karoo deposition expanded northward over the interior beyond that of the confined pre-Gondwanan Cape Sequence. The axis of maximum thickness of the Permian-Triassic foredeep remained near the South Crop of the Karoo Basin; the parallel drainage axis migrated northward from an initial distance of 80 km during Dwyka deposition through 400 km during Ecca deposition and 550 km during Beaufort to a final 1,000 km during Stormberg deposition. The increasing separation of foredeep and drainage axis reflects the widening during the growth of the Cape Fold Belt of the southern depositional flank of the Karoo Basin at the expense of the starved northern cratonic side. Only during Stormberg deposition did the northern craton match the Cape Fold Belt as a source of voluminous sediment. Downloaded from 224 J. J. Veevers and Others Renewed and more extensive deposition in the Late Triassic corresponds to a singularity in Pangean history: terminal compression of foldbelts (Cape Fold Belt, Bowen-Sydney Basin, Canning Basin) and widespread subsidence, mainly in rifts that prefigured the divergent margins of the Atlantic and Indian Ocean regions. The subsequent Karoo volcanism reflects the increased activity of Pangean hotspots. This synopsis of the geologic history of southern Africa, south of 26°S, focuses on the Permian-Triassic Karoo Sequence of the Karoo Basin in its Gondwanan setting. The Karoo Sequence (Figs. 1-3) is a component of the Pangean Supersequence of the Gondwanaland cratonic province of Pangea (Veevers, 1990). In the latest Carboniferous (290 Ma), the Karoo Sequence started to accumulate in the oval-shaped Karoo Basin and narrow, fault-affected, Zambezian basins. From 277 Ma, the Karoo Basin became a foreland basin that subsided along a zone of inherited (pre-Gondw...

show abstract

Section: Karoo Sequencementioning

confidence: 99%

Section: Tap-tapinocephalus Cis-cistecephalus Dap-daptocephalus Lymentioning

confidence: 99%

Southern Africa: Karoo Basin and Cape Fold Belt

Veevers¹,

Cole²,

Cowan³

1994

Geological Society of America Memoirs

106

View full text Add to dashboard Cite

show abstract

“…Possible methods of control are catalysis or adhesion. Transport by ground water seems likely in view of the fact that most uranium is found in the more permeable lithologies (Turner, 1985).…”

Section: Paragenesismentioning

confidence: 99%

Letlhakane project: case study in complex uranium mineralogy and its geometallurgical implications

Brough¹,

Bowell²,

Grogan

et al. 2013

Mining Technology

View full text Add to dashboard Cite

Uranium mineralisation within the Letlhakane tenement, Botswana, is complex and characterised by three different ores (primary, oxidised and secondary). From a geometallurgical viewpoint, most uranium occurs in coarse grained, and/or highly soluble minerals; favourable characteristics for conventional extractive metallurgical methods. However, there are several factors presenting challenging metallurgical issues including: the presence of refractory ore (,30% of the uranium); the frequent encapsulation of uranium minerals within the first two ore types; minor gypsum and major carbonate present within the secondary ore type; and high clay content throughout, potentially necessitating agglomeration of the ore. An optimised processing flowsheet has been developed involving two distinct flow paths. First, extraction of the secondary uranium ore through agglomeration and an acid heap leach. Second, a beneficiation stage involving fine grinding and radiometric sorting forming a preconcentrate; followed by a strong, two-stage acid agitation leach to extract the uranium from the refractory uranium bearing minerals.

show abstract

“…They are the host rocks of some uranium deposits of the infiltration type (Turner 1985). They are the host rocks of some uranium deposits of the infiltration type (Turner 1985).…”

Section: Mineralization Of the Anoxic Sediments Of Collision Marginsmentioning

confidence: 99%

Metallogeny, structural, lithological and time controls of ore deposition in anoxic environments

Křı́bek

1991

Mineral. Deposita

View full text Add to dashboard Cite

Abstraet, Accumulation of metals in anoxic environments occurs by sorption and precipitation from seawater, fossil brines or hydrothermal solutions. Metals can be remobilized during subsequent metamorphic and magmatic processes and form ore deposits. This type of mineralization is governed chiefly by the type of tectonic setting of the anoxic environment. Carbonaceous sediments of passive margins contain only subeconomic concentrations of uranium, vanadium and molybdenum. Cubearing black shales and the submarine-exhalative type of mineralization are confined to the environments of continental rifts and aulacogens or to back-arc basins of active margins. Metamorphogenic deposits are mainly connected with collision margins but they may also occur in other types of tectonic environments. The formation of Cu-bearing black shales was controlled by period of low sea-level during the break-up of supercontinents in the Earth's evolution. Increased contents of uranium and vanadium accumulated in black shales in periods of sealevel highstands. Lithological control is apparent in deposits of Cu-bearing and uraniferous black shales. On the contrary, the occurrence of polymetallic mineralization does not depend on the lithological maturity of carbonaceous sediments.

show abstract

Uranium mineralization in the Karoo Basin, South Africa

Cited by 19 publications

References 15 publications

Southern Africa: Karoo Basin and Cape Fold Belt

Southern Africa: Karoo Basin and Cape Fold Belt

Letlhakane project: case study in complex uranium mineralogy and its geometallurgical implications

Metallogeny, structural, lithological and time controls of ore deposition in anoxic environments

Contact Info

Product

Resources

About