Organic matter and sandstone-type uranium deposits: a primer

1979 ◽  
Author(s):  
Joel S. Leventhal
Keyword(s):  
Organic Matter ◽  
Uranium Deposits

scholarly journals Uranium deposits of Franceville basin (Gabon): Role of organic matter and oil cracking on uranium mineralization

2020 ◽  
Vol 123 ◽  
pp. 103579
Author(s):  
Andreï Lecomte ◽  
Raymond Michels ◽  
Michel Cathelineau ◽  
Christophe Morlot ◽  
Marc Brouand ◽  
...  
Keyword(s):  
Organic Matter ◽  
Uranium Mineralization ◽  
Uranium Deposits ◽  
Oil Cracking

scholarly journals Sandstone-Hosted Uranium Deposits as a Possible Source for Critical Elements: The Eureka Mine Case, Castell-Estaó, Catalonia

Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 34 ◽  
Author(s):  
Montgarri Castillo-Oliver ◽  
Joan Carles Melgarejo ◽  
Lisard Torró ◽  
Cristina Villanova-de-Benavent ◽  
Marc Campeny ◽  
...  
Keyword(s):  
Organic Matter ◽  
Low Temperature ◽  
Black Shales ◽  
Hydrothermal Fluids ◽  
Uranium Deposits ◽  
Critical Metals ◽  
Fine Grained ◽  
Critical Elements ◽  
By Products ◽  
Red Bed

The Eureka deposit in Castell-estaó in the Catalan Pyrenees is a Cu–U–V deposit, hosted by Triassic red-bed sandstones, and classified here as a low-temperature, sandstone-hosted stratabound metamorphite U deposit. The main mineralisation is stratabound, related to coal-bearing units and produced during the Alpine deformation by migration of hydrothermal fluids. In this stage, the original sedimentary and diagenetic components (quartz and calcite, micas, hematite and locally apatite) were replaced by a complex sequence of roscoelite, fine-grained REE phosphates, sulphides and Ni–Co arsenides and sulpharsenides, Ag–Pb selenides, bismuth phases, sulphosalts and uraninite. The black shales of the Silurian sediments underlying the deposit and the nearby Carboniferous volcanoclastic rocks are interpreted as the source of the redox-sensitive elements concentrated in Eureka. The sulphur source is related to leaching of the evaporitic Keuper facies. The REE transport would be facilitated by SO4-rich solutions. The reduction of these solutions by interaction with organic matter resulted in the widespread precipitation of REE and redox-sensitive elements, including many critical metals (V, Bi, Sb, Co), whereas barite precipitated in the oxidized domains. The occurrence of similar enrichments in critical elements can be expected in other similar large uranium deposits, which could be a source of these elements as by-products.

Significance of diagenesis for the origin of Witwatersrand-type uraniferous conglomerates

1979 ◽  
Vol 291 (1381) ◽  
pp. 277-287 ◽  
Keyword(s):  
South Africa ◽  
Organic Matter ◽  
Coarse Grained ◽  
Uranium Deposits ◽  
Multi Stage ◽  
Ore Minerals ◽  
History Of ◽  
Diverse Origin ◽  
Reducing Bacteria ◽  
Petrographic Study

A petrographic study of pyrite may be the key to the understanding of the Witwatersrand (South Africa) gold-uranium deposits: the sediments of the Witwatersrand Supergroup contain at least nine types of pyrite, namely (1) Laminated pyrite seams; (2) pyrite nodules in shales; (3) pyrite nodules in quartzite and conglomerate; (4) pyrite as overgrowths on carbonaceous filaments; (5) pyrite filling pore spaces and replacing clasts; (6) pyrite replacing detrital magnetite; (7) allogenic fragments of laminated pyrite; (8) allogenic fragments of pyrite nodules; and (9) allogenic fragments of coarse-grained pyrite. Types 1-6 probably formed during diagenesis of the sediment due to the activity of sulphate-reducing bacteria; types 7 and 8 are transported fragments of diagentic pyrite; type 9 may be of diverse origin, but may also in part be transported fragments of diagenetic pyrite. Pyrite petrography suggests a multi-stage history of ore enrichment: diagenetic precipitation of gold, uraninite and pyrite in sediments containing organic matter, followed by erosion, transport of allogenic fragments of ore minerals for short distances, and concentration in lag gravels at channel bottoms and unconformities. Repeated cycles of weathering, diagenetic precipitation from weathering solutions, erosion, minor transport and redeposition may have caused the extraordinary enrichment of the ores on major unconformities in the Upper Witwatersrand Supergroup.

Characterization of organic matter associated with uranium deposits in the Francevillian formation of Gabon (lower proterozoic)

1990 ◽  
Vol 15 (1) ◽  
pp. 73-85 ◽  
Author(s):  
F. Cortial ◽  
F. Gauthier-Lafaye ◽  
G. Lacrampe-Couloume ◽  
A. Oberlin ◽  
F. Weber
Keyword(s):  
Organic Matter ◽  
Uranium Deposits ◽  
Lower Proterozoic

Nature and Role of Organic Matter in Sandstone Uranium Deposits, Grants Uranium Region, New Mexico, USA

1993 ◽  
pp. 239-275 ◽  
Author(s):  
C. E. Turner ◽  
N. S. Fishman ◽  
P. G. Hatcher ◽  
E. C. Spiker
Keyword(s):  
Organic Matter ◽  
New Mexico ◽  
Uranium Deposits
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