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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Métallogenèse de l'uranium dans la région de Ladoga (Karélie, Russie)

Shurilov, Alexander Cuney, Michel. Lespinasse, Marc. Kushnerenko, Vladimir. January 2008 (has links) (PDF)
Thèse de doctorat : Géosciences : Nancy 1 : 2008. / Titre provenant de l'écran-titre.
22

Chemical mass transfer and solution flow in Wyoming roll-type uranium deposits

Capuano, Regina M. January 1977 (has links)
No description available.
23

Diffusion of radom-222 in overburden and its application to uranium exploration

Soonawala, Noshirwan M. January 1976 (has links)
No description available.
24

Paragenesis and fluid history of the Karku unconformity-uranium deposit, Pasha-Ladoga Basin, Western Russia

Rice-Bredin, Sarah 12 September 2012 (has links)
The Karku unconformity-type uranium deposit is located in the Proterozoic Pasha-Ladoga Basin in western Russia. The deposit is located in basinal sandstones near a reverse fault that offsets the unconformable contact with underlying graphite-bearing biotite schist basement rocks. Meteoric water-sourced diagenetic fluids altered sandstones outside mineralized zones, producing clay assemblages of interstratified illite-smectite with minor dickite and Fe-rich chlorite, and fluid isotopic compositions of d18O = 3.3‰ to 6.0‰ and dD = -55‰ to -44‰ at 130°C. Altered sandstones within zones of mineralization include a clay mineral assemblage of Fe-rich chlorite with minor illite, and fluid isotopic compositions of d18O = 6.0‰ to 12.7‰ and dD = -8‰ to -4‰ at 210°C, caused by seawater-derived fluids related to ore formation. In addition, a Mg-chlorite occurring with uraninite in the mineralized lenses was identified. Dating of Karku uraninite using U/Pb isotope systematics from LA-MC-ICP-MS, LA-HR-ICP-MS, and SIMS gave upper-intercept ages of 1467 ± 39 Ma, 1459 ± 74 Ma, and 1302 ± 150 Ma respectively. The lower-intercept age of all methods was around 300 Ma. A formation model for the Karku uranium deposit is proposed based on the results of this study and incorporating previously published. Early, low-temperature diagenesis resulted in cementation of distal, basin-marginal sandstones by mixed-layer illite-smectite clays, preventing later, higher-temperature diagenetic alteration in this unit. Sandstones towards the centre of the basin allowed the circulation of higher-temperature basinal fluids that later flowed along the unconformity to the graphitic schist unit. A fault intersecting this unit facilitated the mixing of basement and basinal fluids, causing uraninite to precipitate at the unconformity. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2012-09-12 17:10:28.124
25

Sandstone uranium deposits of Nebraska and Colorado: a comparative study

Meek, Angela 26 June 2014 (has links)
Sandstone-type uranium deposits are among the most economic sources of uranium. Despite their significance, the tabular deposits on the Colorado Plateau and roll-front deposits in Nebraska have not been studied adequately. There are important differences between the tabular Colorado Plateau and Nebraska roll-front deposits, including their ore mineralogy, distribution and habit of ore-bodies, alteration, and mechanisms of ore deposition. The U-Pb ages of uranium minerals from the Colorado deposits indicate four stages of mineralization, spanning from the early Oligocene to late Pliocene. Uranium and V minerals include coffinite, montroseite and carnotite and are associated with both biogenic and non-biogenically precipitated sulphides. Two generations of coffinite mineralization from the Three Crow roll-front deposit in Nebraska were identified. This mineralization precipitated during the early Pliocene and late Miocene. The U-Th activity ratios of U minerals suggest a net accumulation of uranium within the limbs of the roll-front. Evolving oxidation fronts are implied by multiple sulphide generations as indicated by their delta 34S compositions.
26

Le Complexe granitique hyperalumineux de Saint-Sylvestre, : nord-ouest du Massif central français... /

Friedrich, Marc. January 1984 (has links)
Thèse 3e cycle--Pétrologie et minéralogie--Nancy I, 1983. / Bibliogr. p. 325-342. Résumé en français et en anglais.
27

Contexte structural des gisements d'uranium de la Marche occidentale : fracturation, circulations fluides, propagation de l'épisyénitisation ... /

Lespinasse, Marc. January 1984 (has links)
Thèse 3e cycle--Géologie structurale, métallogénie--Institut national polytechnique de Lorraine, 1984. / Bibliogr. p. 189-196. Résumé en anglais.
28

Les Gisements d'uranium associés au volcanisme acide tertiaire de la Sierra de Peña Blanca (Chihuahua, Mexique) /

George, Brigitte, January 1983 (has links)
Thèse 3 cycle--Pétrologie, géochimie, métallogénie--Paris VI, 1982. / Bibliogr. p. 259-266. Résumés en français, anglais et espagnol.
29

Distribution et modes de fixation de l'uranium dans les grands types de pédogenèses climatiques et stationelles sur roches cristallines.

Gueniot, Bernard, January 1900 (has links)
Th. 3e cycle--Agro-éco-pédol.--Nancy 1, 1983. N°: 249.
30

Minéralogie, pétrologie et géochimie du Permien de Lodève, Hérault, France : Diagenèse précoce, altération feldspathisante et mise en place des minéralisations uranifères /

Clément, Jean-Yves, January 1986 (has links)
Th. univ.--Géochimie de la surface--Poitiers, 1986. / Bibliogr. p. 129-137.

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