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Sample records for surficial uranium deposits

  1. Surficial uranium deposits in Botswana

    International Nuclear Information System (INIS)

    Mortimer, C.

    1984-01-01

    The known surficial uranium deposits in Botswana are supergene concentrations either in soils above lower Karoo sediments, or in peat and calcified alluvium of dry stream courses in the Kalahari Desert. A number of uranium occurrences lie above Karoo sedimentary rocks and of these Mokobaesi No. 1 is the best explored. It is a tabular body of disseminated uranium ochre occurring immediately below surface in calcrete and calcified mudstone. The uranium is believed to have migrated upwards from the Karoo rocks. Reconnaissance investigations show that moderately anomalous uranium occurs at a number of localities in peat and calcified sediments that have been deposited in ephemeral water courses. None of these deposits are economic, but the known occurrences are encouraging indications that such deposits may exist in the thick Tertiary to Recent ''Kalahari beds'', that were deposited in diverse palaeoenvironments. (author)

  2. Surficial uranium deposits: summary and conclusions

    International Nuclear Information System (INIS)

    Otton, J.K.

    1984-01-01

    Uranium occurs in a variety of surficial environments in calcretes, gypcretes, silcretes, dolocretes and in organic sediments. Groundwater moving on low gradients generates these formations and, under favourable circumstances, uranium deposits. A variety of geomorphic settings can be involved. Most surficial deposits are formed in desert, temperate wetland, tropical, or transitional environments. The largest deposits known are in sedimentary environments in arid lands. The deposits form largely by the interaction of ground or surface waters on the geomorphic surface in favourable geologic terrains and climates. The deposits are commonly in the condition of being formed or reconstituted, or being destroyed. Carnotite is common in desert deposits while in wetland deposits no uranium minerals may be seen. Radioactive disequilibrium is common, particularly in wetland deposits. Granites and related rocks are major source rocks and most large deposits are in regions with enriched uranium contents, i.e. significantly greater than 5 ppm uranium. Uranium dissolution and transport is usually under oxidizing conditions. Transport in desert conditions is usually as a bicarbonate. A variety of fixation mechanisms operate to extract the uranium and form the deposits. Physical barriers to groundwater flow may initiate ore deposition. Mining costs are likely to be low because of the near surface occurrence, but there may be processing difficulties as clay may be present and the saline or carbonate content may be high. (author)

  3. Definition and classification of surficial uranium deposits

    International Nuclear Information System (INIS)

    Toens, P.D.; Hambleton-Jones, B.B.

    1984-01-01

    Uraniferous surficial deposits may be broadly defined as uraniferous sediments or soils, usually of Tertiary to Recent age, that have not been subjected to deep burial and may or may not have been cemented to some degree. Evaluation of the available literature shows that confusion has arisen as to the use of the term ''calcrete'' when describing fluviatile sediments that have been calcified to a greater or lesser degree. It is felt that a useful purpose would be served by proposing a classification system which may go some way towards a redefinition of the applicable terminology. Unfortunately the terms ''calcrete'' or ''valley calcrete'' have been used to define Tertiary to Recent sediments ranging from boulder beds to silts which, in some Namibian examples, contain between 5 and 50% CaCO 3 and as much as 90% total carbonate in some Australian surficial uranium deposits. It is proposed that the detrital material constituting the sediments be prefixed with the terms calcareous, dolomitic, gypsiferous, halitiferous or ferruginous (e.g. calcareous grit) rather than the terms calcrete, dolocrete, gypcrete, and ferricrete, all of which have genetic connotations. The latter group of terms are preferably used for the pedogenic uranium deposits only. This will have the effect of placing these deposits in categories of their own and not confusing the issue with the overprint of pedogenic calcrete or duricrustal deposits which may or may not be present. This view is not shared by some authorities notably Butt and Carlisle (see this volume). (author)

  4. The genesis of surficial uranium deposits

    International Nuclear Information System (INIS)

    Boyle, D.R.

    1984-01-01

    Surficial uranium deposits can form in such diverse environments as calcareous-dolomitic-gypsiferous fluvial and aeolian valley sediments in hot arid and semi-arid regions, oxidizing and reducing alkaline and saline playas, highly organic and/or clay-rich wetland areas, calcareous regoliths in arid terranes, laterites, lake sediments, and highly fractured zones in igneous and metamorphic basement complexes. Formation of ore is governed by the interrelationships between source of ore-forming elements, mechanisms of migration, environment of deposition, climate, preservation, tectonic history and structural framework. The principal factors controlling mobilization of ore-forming elements from source to site of deposition are the availability of elements in source rocks, presence of complexing agents, climate, nature of source rock regolith and structure of source rock terrane. The major processes governing precipitation of uranium in the surficial environment are reduction mechanisms, sorption processes, dissociation of uranyl complexes, change in redox states of ore-forming constituents, evaporation of surface and groundwaters, change in partial pressure of dissolved carbon dioxide, changes in pH, colloidal precipitation, and mixing of two or more surface and groundwaters. One or a number of these processes may be actively involved in ore formation. (author)

  5. Uranium occurrences in the surficial deposits of Southern Africa

    International Nuclear Information System (INIS)

    Hambleton-Jones, B.B.

    1982-01-01

    This paper outlines the geology of the Tertiary to Recent(10 to 0,1 Ma) surficial uranium deposits in South West Africa/Namibia and South Africa. They occur mainly in the Namib Desert to the east of Walvis Bay in South West Africa/Namibia and in the north-western Cape Province of South Africa. All the deposits can be classified as fluviatile, lacustrine/pan, or pedogenic types. The economic potential of the surficial uranium deposits in the north-western Cape is insignificant compared with their South West African/Namibian counterparts. Most of the deposits occur in gypsiferous fluviatile gravels and lacustrine/pan sediments. The largest of the deposits is a lacustrinal, peat-rich, diatomaceous earth type. The mechanisms for the precipitation of the uranium are discussed

  6. Surficial origin of North American pitchblende and related uranium deposits

    International Nuclear Information System (INIS)

    Langford, F.F.

    1977-01-01

    The ubiquitous association of pitchblende uranium deposits with terrestrial sediments is believed to be the natural result of formation of the orebodies by surficial processes operating under continental conditions. The major uranium deposits of North America illustrate this. The quartz-pebble conglomerate uranium deposits of Elliot Lake, Ontario, have thorium-rich uranium minerals that indicate a detrital origin. With the development of an oxygenic atmosphere before 1,700 m.y. ago, uranium was transported in solution in meteoric surface and near-surface ground water, and produced pitchblende veins in fractures in the basement and in lava flows in terrestrial environments. This accounts for the closee association of fluvial sediments with the pitchblende deposits at Beaverlodge, Rabbit Lake, Baker Lake, and Great Bear Lake, Canada. The development of land plants about 300 m.y. ago produced favorable environments within the terrestrial sandstones themselves, and resulted in the tabular uranium orebodies of the Colorado Plateau. The close relation of tabular orebodies to sedimentation is apparent when compared to recent fluvial sedimentation. In Wyoming, the stratigraphic restriction of the boundary-roll deposits to a few zones in Eocene rocks results from their being remobilized tabular deposits

  7. Uranium in surficial deposits and waters at Palmottu

    International Nuclear Information System (INIS)

    Ahonen, L.; Blomqvist, R.; Ervanne, H.; Suksi, J.; Jaakkola, T.

    1994-01-01

    Occurrence of uranium in surficial formations in the vicinity of an underground U deposit was studied. Several water samples from the Lake Palmottu and nearby springs, three lake sediment cores and three peat cores were collected for the study. Uranium concentrations in the water samples varied from 1.4 to 6.9 mBq/l, reflecting the average concentration of near-surface waters in Finland. In some samples, however, the 234 U/ 238 U activity ratio and water chemistry suggest a partial mixing with deeper groundwaters. In the lake sediments, uranium concentrations increases from 53 Bq/kg in surface layer to five fold in the bottom layers deposited 9000 years ago. In peat cores large variations in uranium concentrations can be observed: from tens of Bq/kg to over 20 kBq/kg of peat ash. The large variation also in the 234 U/ 238 U activity ratio, from 0.79 to l.91, tends to indicate uranium migration to the peat from more than one uranium source. (orig.) (19 refs., 5 figs., 1 tab.)

  8. Uraniferous surficial deposits

    International Nuclear Information System (INIS)

    Toens, P.D.; Hambleton-Jones, B.B.

    1980-10-01

    As a result of the discovery of uranium in surficial deposits of Tertiary to Recent age, in Australia and Southern Africa, increasing attention is being paid to the location and understanding of the genesis of these deposits. The paper discusses the definitions and terminology currently in use and a classification of these deposits is presented. It is concluded that in order to obtain a measure of clarity, the terms calcrete, gypcrete and dolocrete should not be used to describe the uraniferous valley-fill deposits of Southern Africa and Australia [af

  9. Handbook on surficial uranium deposits. Chapter 3. World distribution relative to climate and physical setting

    International Nuclear Information System (INIS)

    Carlisle, D.

    This chapter discusses regional controls which affect the world distribution of surficial chemogenic uranium deposits. The most important of these are (1) climate, (2) geomorphology, including physiographic and climatic stability, and (3) provenance, i.e., the weathering terrain from which uranium and associated substances are derived. The three economically important environments are the calcrete environment, simple evaporative environments and paludal environments. Of these three categories, the calcrete uranium environment is probably the most uniquely constrained in terms of regional climate, geomorphic setting, provenance (vanadium as well as uranium) and especially the need for long term stability of both climate and physiography. Purely evaporative deposits, though subject to some of the same kinds of constraints, can also reflect local circumstances and a wider range of climates, physiographic settings, and source terrains. The third category encompassing bogs, marshes and organic-rich playas can form under an even wider range of climates and settings provided only that organic materials accumulate in abundance and are contacted by uranium-bearing waters. For all of these reasons and also because of the great economic importance of the calcrete environment as well as its relative novelty and complexity the discussion in this chapter is focused on calcrete, dolocrete and gypcrete uranium deposits. Objective data are reviewed first follwed by inferences and suggestions. 13 figures

  10. Sedimentology of a surficial uranium deposit on North Flodelle Creek, Stevens County, Washington

    International Nuclear Information System (INIS)

    Macke, D.L.; Johnson, S.Y.; Otton, J.K.

    1985-01-01

    Surficial accumulations of uranium (up to 0.2 wt. % U/sub 3/O/sub 8/, dry basis) are currently forming in organic-rich, poorly drained sediments deposited in fluvial-lacustrine environments. Known occurrences are in northeastern Washington, northern Idaho, the Sierra Nevada, the Colorado Front Range, New Hampshire, and several areas in Canada. The first accumulation of this type to be mined is in postglacial sediments of a 10-acre boggy meadow along North Flodelle Creek in Stevens County, Washington. The meadow is flanked by hills of fine- to medium-grained two-mica quartz monzonite that are mantled by glacial drift of late Wisconsin age (about 18,000 to 11,500 yr B.P.). Relatively thick, hummocky deposits of this same glacial drift impede drainage at the lower end of the meadow. Following ice retreat, glacial sediments on the meadow floor were reworked by fluvial processes, and patches of organic-rich sediment may have formed in ice-melt depressions. About 6700 yr B.P., a blanket of Mazama ash from the Crater Lake eruption was deposited in the meadow. Shortly thereafter, a beaver dam across the lower end of the meadow further restricted drainage, and peat and organic mud accumulated in the pond behind the dam. The dam is preserved in the stratigraphic record as a sheet-like body of woody peat (with beaver-gnawed sticks) about 100m wide and 60 cm thick. After the gradual influx of sand and coarse silt had filled the pond, and the beavers had abandoned the site, fluvial deposition was reestablished

  11. Uraniferous surficial deposits in Southern Africa

    International Nuclear Information System (INIS)

    Hambleton-Jones, B.B.; Levin, M.; Wagener, G.F.

    1986-01-01

    Surficial uranium deposits are located in the north-western Cape Province of South Africa, in the Namib Desert east of Walvis Bay in South West Africa/Namibia and in the Serule Block of Botswana. They have been classified into the valley-fill, lacustrine, and pedogenic types. Carnotite is the main uranium-bearing mineral in the larger surficial deposits, with other minerals such as soddyite and phosphuranylite occurring locally. Uraninite or urano-organic complexes occur in the reducing environments of the diatomaceous earth, peat-rich deposits. Economically, the valley-fill type is the most important, with the largest deposits occurring in South West Africa/Namibia. In South West Africa/Namibia the valley-fill surficial uranium deposits occur in the Tumas and Langer Heinrich formations of the Teriary to Recent Namib Group. The Tubas, Langer Heinrich, and Welwitchia deposits are discussed: in them, carnotite occurs in calcareous and gypsiferous fluvial gravels. The pedogenic deposit at Mile 72 occurs in weathered granite and overlying gypcrete and has little economic potential. The economic potential of the surficial deposits in the north-western Cape Province is very limited in comparison with their South West African/Namibian counterparts, but the most important deposits are the lacustrine type, in particular those containing peat and diatomaceous earth. The mechanisms for the precipitation and preservation of the uranium are discussed

  12. Surficial uranium occurrences in relation to climate and physical setting

    International Nuclear Information System (INIS)

    Carlisle, D.

    1984-01-01

    Important surficial chemogenic uranium deposits develop within 1) calcretes, 2) simple evaporative environments and 3) bogs or similar organic environments (''young'' uranium). Calcrete occurrences are the largest, most novel and most dependent upon extreme aridity and geomorphic stability. Economic calcrete deposits are nonpedogenic, resulting from near-surface groundwater transport and lateral concentration of uranium, vanadium, potassium, calcium, and magnesium rather than from ordinary soil-forming processes. Their genesis is essentially observable in Western Australia where carnotite-bearing nonpedogenic calcrete is currently forming under a unique aridic soil moisture regime and where major deposits have formed under similar climates during the last few thousand years. Rainfall is less than 250mm annually, only 1/12 to 1/20 of potential evaporation and concentrated almost entirely in episodic late summer storms. Outside this region, under less arid conditions, only pedogenic calcretes form and they do not contain economic uranium. In southern Africa, calcrete and gypcrete uranium deposits, although Late Tertiary to Quaternary in age, are also nonpedogenic and appear to have formed under similar climatic constraints with local variations in geomorphology and calcrete morphology. (author)

  13. Uranium deposit research, 1983

    International Nuclear Information System (INIS)

    Ruzicka, V.; LeCheminant, G.M.

    1984-01-01

    Research on uranium deposits in Canada, conducted as a prerequisite for assessment of the Estimated Additional Resources of uranium, revealed that (a) the uranium-gold association in rudites of the Huronian Supergroup preferably occurs in the carbon layers; (b) chloritized ore at the Panel mine, Elliot Lake, Ontario, occurs locally in tectonically disturbed areas in the vicinity of diabase dykes; (c) mineralization in the Black Sturgeon Lake area, Ontario, formed from solutions in structural and lithological traps; (d) the Cigar Lake deposit, Saskatchewan, has two phases of mineralization: monomineralic and polymetallic; (e) mineralization of the JEB (Canoxy Ltd.) deposit is similar to that at McClean Lake; (f) the uranium-carbon assemblage was identified in the Claude deposit, Carswell Structure; and (g) the Otish Mountains area, Quebec, should be considered as a significant uranium-polymetallic metallogenic province

  14. Geology of hydrothermal uranium deposits

    International Nuclear Information System (INIS)

    Korolev, K.G.; Belov, V.K.; Putilov, G.S.

    1983-01-01

    Geological characteristics of hydrothermal phosphorus-uranium deposits placed in sedimentary, igneous-sedimentary, metamorphic and intrusion formations are presented. Attention is paid to mineral composition, texture and structure of ores, their genesis, tectonics. Geochemical peculiarities of ores and age of molybdenum-uranium and uranium deposits are described. Geological criteria and prospecting features of uranium and uranium-molybdenum deposits are given

  15. Uranium deposits in Africa

    International Nuclear Information System (INIS)

    Wilpolt, R.H.; Simov, S.D.

    1979-01-01

    Africa is not only known for its spectacular diamond, gold, copper, chromium, platinum and phosphorus deposits but also for its uranium deposits. At least two uranium provinces can be distinguished - the southern, with the equatorial sub-province; and the south Saharan province. Uranium deposits are distributed either in cratons or in mobile belts, the first of sandstone and quartz-pebble conglomerate type, while those located in mobile belts are predominantly of vein and similar (disseminated) type. Uranium deposits occur within Precambrian rocks or in younger platform sediments, but close to the exposed Precambrian basement. The Proterozoic host rocks consist of sediments, metamorphics or granitoids. In contrast to Phanerozoic continental uranium-bearing sediments, those in the Precambrian are in marginal marine facies but they do contain organic material. The geology of Africa is briefly reviewed with the emphasis on those features which might control the distribution of uranium. The evolution of the African Platform is considered as a progressive reduction of its craton area which has been affected by three major Precambrian tectonic events. A short survey on the geology of known uranium deposits is made. However, some deposits and occurrences for which little published material is available are treated in more detail. (author)

  16. Uranium deposits through time

    International Nuclear Information System (INIS)

    Derry, D.R.

    1980-01-01

    The distribution of different types of uranium deposits through geological time has been noted by various authors, especially as affecting deposits formed in the Precambrian era. While this is significant, it may have been oversimplified by grouping deposits within geological time limits that are very extensive when compared with Phanerozoic groupings. As more detailed information becomes available, we find that some of the higher-grade deposits have complicated histories involving several stages of concentration separated by long periods of time. A comparison of the proportion of uranium production and reserves contributed by individual classes (and geological ages) of deposits shows a changing trend in favour of the unconformity class. Possibly more attention should be paid to metallographic uranium areas and their localizations. Some areas, e.g. Gabon, West Africa and Baker Lake, N.W.T., have more than one type of uranium deposit. A further consideration is that much of the known uranium reserves in the non-Communist world lies within a dozen areas, each ranging between 3000 and 130 000 km 2 . It is possible that such uranium metallographic areas were localized by very ancient fracture systems, now not easily recognized, in the original Earth's crust

  17. Uranium deposits of Zaire

    International Nuclear Information System (INIS)

    Kitmut, D.; Malu wa Kalenga

    1979-01-01

    Since April 1960, following the closing of the Shinkolobwe mine, the Republic of Zaire has ceased to be a producer of uranium. Nevertheless, Gecamines (Generale des carrieres et mines du Zaire), a wholly state-owned company, is continuing its research on uranium occurrences which have been discovered in its concession in the course of aerial radiometric prospecting. The most recent campaign was the one carried out in 1969 and 1972 by Hunting Company. On-the-ground verification of these shows has not yet resulted in the discovery of a workable deposit. There are other sectors cutting across Zaire which might well contain uranium deposits: this is true of the sedimentary phosphates of the region of Lower Zaire as well as of the frontier region between Zaire and the Central African Empire. However, no detailed exploration work has yet been carried out. (author)

  18. Uranium ore deposits

    International Nuclear Information System (INIS)

    Angelelli, Victorio.

    1984-01-01

    The main uranium deposits and occurrences in the Argentine Republic are described, considering, in principle, their geologic setting, the kind of 'model' of the mineralization and its possible origin, and describing the ore species present in each case. The main uraniferous accumulations of the country include the models of 'sandstong type', veintype and impregnation type. There are also other kinds of accumulations, as in calcrete, etc. The main uranium production has been registered in the provinces of Mendoza, Salta, La Rioja, Chubut, Cordoba and San Luis. In each case, the minerals present are mentioned, having been recognized 37 different species all over the country (M.E.L.) [es

  19. Sandstone-type uranium deposits

    International Nuclear Information System (INIS)

    Finch, W.I.; Davis, J.F.

    1985-01-01

    World-class sandstone-type uranium deposits are defined as epigenetic concentrations of uranium minerals occurring as uneven impregnations and minor massive replacements primarily in fluvial, lacustrine, and deltaic sandstone formations. The main purpose of this introductory paper is to define, classify, and introduce to the general geologic setting for sandstone-type uranium deposits

  20. Uranium deposits in granitic rocks

    International Nuclear Information System (INIS)

    Nishimori, R.K.; Ragland, P.C.; Rogers, J.J.W.; Greenberg, J.K.

    1977-01-01

    This report is a review of published data bearing on the geology and origin of uranium deposits in granitic, pegmatitic and migmatitic rocks with the aim of assisting in the development of predictive criteria for the search for similar deposits in the U.S. Efforts were concentrated on the so-called ''porphyry'' uranium deposits. Two types of uranium deposits are primarily considered: deposits in pegmatites and alaskites in gneiss terrains, and disseminations of uranium in high-level granites. In Chapter 1 of this report, the general data on the distribution of uranium in igneous and metamorphic rocks are reviewed. Chapter 2 contains some comments on the classification of uranium deposits associated with igneous rocks and a summary of the main features of the geology of uranium deposits in granites. General concepts of the behavior of uranium in granites during crustal evolution are reviewed in Chapter 3. Also included is a discussion of the relationship of uranium mineralization in granites to the general evolution of mobile belts, plus the influence of magmatic and post-magmatic processes on the distribution of uranium in igneous rocks and related ore deposits. Chapter 4 relates the results of experimental studies on the crystallization of granites to some of the geologic features of uranium deposits in pegmatites and alaskites in high-grade metamorphic terrains. Potential or favorable areas for igneous uranium deposits in the U.S.A. are delineated in Chapter 5. Data on the geology of specific uranium deposits in granitic rocks are contained in Appendix 1. A compilation of igneous rock formations containing greater than 10 ppM uranium is included in Appendix 2. Appendix 3 is a report on the results of a visit to the Roessing area. Appendix 4 is a report on a field excursion to eastern Canada

  1. Types of hydrogenic uranium deposits

    International Nuclear Information System (INIS)

    Kondrat'eva, I.A.; Lisitsin, A.K.; Komarova, G.V.

    1980-01-01

    Principles of uranium deposit systematics are considered. Systematization, presented in this paper, is based on a regularity that the main industrial exogenic epigenetic uranium concentrations are formed in zones of reduction geochemical barriers. Types of uranium-bearing ground waters and nature of uranium reducing agents were taken into account during systematization. Hydrogenic uranium deposits are related to 3 types: formed by ground (1 type), stratal (2 type) and vein (3 type) waters. By the nature of uranium reducing agents 2 deposit subtypes are marked out: A - in rocks with syngenetic reducing agents, B - in rocks with epigenetic reducing agents. Uranium deposits are also differentiated by nature of reducing agents distribution in ore-containing rocks [ru

  2. Uranium extraction from underground deposits

    International Nuclear Information System (INIS)

    Wolfe, C.R.

    1982-01-01

    Uranium is extracted from underground deposits by passing an aqueous oxidizing solution of carbon dioxide over the ore in the presence of calcium ions. Complex uranium carbonate or bicarbonate ions are formed which enter the solution. The solution is forced to the surface and the uranium removed from it

  3. NURE uranium deposit model studies

    International Nuclear Information System (INIS)

    Crew, M.E.

    1981-01-01

    The National Uranium Resource Evaluation (NURE) Program has sponsored uranium deposit model studies by Bendix Field Engineering Corporation (Bendix), the US Geological Survey (USGS), and numerous subcontractors. This paper deals only with models from the following six reports prepared by Samuel S. Adams and Associates: GJBX-1(81) - Geology and Recognition Criteria for Roll-Type Uranium Deposits in Continental Sandstones; GJBX-2(81) - Geology and Recognition Criteria for Uraniferous Humate Deposits, Grants Uranium Region, New Mexico; GJBX-3(81) - Geology and Recognition Criteria for Uranium Deposits of the Quartz-Pebble Conglomerate Type; GJBX-4(81) - Geology and Recognition Criteria for Sandstone Uranium Deposits in Mixed Fluvial-Shallow Marine Sedimentary Sequences, South Texas; GJBX-5(81) - Geology and Recognition Criteria for Veinlike Uranium Deposits of the Lower to Middle Proterozoic Unconformity and Strata-Related Types; GJBX-6(81) - Geology and Recognition Criteria for Sandstone Uranium Deposits of the Salt Wash Type, Colorado Plateau Province. A unique feature of these models is the development of recognition criteria in a systematic fashion, with a method for quantifying the various items. The recognition-criteria networks are used in this paper to illustrate the various types of deposits

  4. Vein-type uranium deposits

    International Nuclear Information System (INIS)

    Rich, R.A.; Holland, H.D.; Petersen, U.

    1975-01-01

    A critical review is presented of published data bearing on the mineralogy, paragenesis, geochemistry, and origin of veiw-type uranium deposits. Its aim is to serve as a starting point for new research and as a basis for the development of new exploration strategies. During the formation of both vein and sandstone types of deposits uranium seems to have been dissolved by and transported in rather oxidized solutions, and deposited where these solutions encountered reducing agents such as carbon, sulfides, ferrous minerals and hydrocarbons. Granitic rocks abnormally enriched in uranium have apparently been the most common source for uranium in vein-type deposits. Oxidizing solutions have been derived either from the surface or from depth. Surface solutions saturated with atmospheric oxygen have frequently passed through red bed or clean sandstone conduits on their way to and from uranium source rocks. Deep solutions of non-surface origin have apparently become sufficiently oxidizing by passage through and equilibration with red beds. The common association of clean sandstones or red beds with uranium-rich granites in the vicinity of vein-type uranium deposits is probably not fortuitous, and areas where these rock types are found together are considered particularly favorable targets for uranium exploration

  5. Electrolytic nickel deposits upon uranium

    International Nuclear Information System (INIS)

    Baudin, G.; Chauvin, G.; Coriou, H.; Hure, J.

    1958-01-01

    The authors present a new possibility to protect uranium by very adherent nickel deposits got by aqueous medium electrolysis. Surface treatment of uranium is based upon the chemical etching method from Lietazke. After thermal treatments at 600, 700 and 800 deg. C, under vacuum, a good intermetallic U-Ni diffusion is observed for each case. (author) [fr

  6. Unconformity-related uranium deposits

    International Nuclear Information System (INIS)

    Ewers, G.R.; Ferguson, J.

    1985-01-01

    Documentation of ore deposit characterisation is being undertaken to assess the controls of uranium mineralisation associated with Proterozoic unconformities. The Turee Creek uranium prospect in Western Australia is associated with a faulted contact between the Middle Proterozoic Kunderong Sandstone and the Lower Proterozoic Wyloo Group

  7. Uranium and lanthanides in surficial sediments of Laguna Ojo de Liebre and evaporation ponds of Exportadora de Sal, Guerrero Negro, México.

    Science.gov (United States)

    Grajeda-Muñoz, M. M.; Choumiline, E.; Zaposhnikov, D.

    2007-05-01

    To assess uranium and lanthanides behavior in hypersaline environments, surficial sediment samples were taken from Laguna Ojo de Liebre as well as from the evaporation ponds of Exportadora de Sal (the largest natural salt producing facility in the continent). A total of 63 surficial sediment samples from the laguna and 30 samples from the ponds were analyzed by inductive coupled plasma-mass spectrometry for uranium (sediments, deposits and solution) and instrumental neutron activation analysis for REEs in sediments and deposits. Results show that the behavior is all but similar between light and heavy REEs with the exception of Eu which shows a very different pattern of surficial distribution in Laguna Ojo de Liebre with a maximum concentrations in the sediments near the head of the lagoon. Data normalized with North American Shale Composite (NASC) show 3 distinct signature patterns on the surficial sediments, all of them enriched regarding the values of NASC. As for U total content in sediments and solid deposits it shows a higher concentration towards the head of the lagoon (3 mg/kg), from where the water is pumped to the sequence of evaporation ponds, with the lowest values being close to 1 mg/kg near the mouth of the lagoon. The interesting phenomenon begins in the evaporation ponds, where uranium is almost constant in sediments and deposits (0.15-1.5 mg/kg) but behaves conservately in the brine solution, increasing proportionally with salt content (U, 5-20 mg/kg; salt content, 40-250 g/kg). Non lithogenic U was calculated with Sc as reference. Most of the measured U was non lithogenic in the sediments of the lagoon and ponds. The distribution coefficient k= U(non-lith)/U(dis) shows a maximum value at ponds I and II (salt content 40-80 g/kg) decreasing with increasing salinity.

  8. Uranium deposits in volcanic rocks

    International Nuclear Information System (INIS)

    1985-01-01

    Twenty-eight papers were presented at the meeting and two additional papers were provided. Three panels were organized to consider the specific aspects of the genesis of uranium deposits in volcanic rocks, recognition criteria for the characterization of such deposits, and approaches to exploration. The papers presented and the findings of the panels are included in the Proceedings. Separate abstracts were prepared for each of these papers

  9. IAEA Classification of Uranium Deposits

    International Nuclear Information System (INIS)

    Bruneton, Patrice

    2014-01-01

    Classifications of uranium deposits follow two general approaches, focusing on: • descriptive features such as the geotectonic position, the host rock type, the orebody morphology, …… : « geologic classification »; • or on genetic aspects: « genetic classification »

  10. Vein type uranium deposits

    International Nuclear Information System (INIS)

    1986-01-01

    Veins are tabular- or sheet-like masses of minerals occupying or following a fracture or a set of fractures in the enclosing rock. They have been formed later than the country rock and fractures, either by filling of the open spaces or by partial or complete replacement of the adjoining rock or most commonly by both of these processes combined. This volume begins with the occurrences and deposits known from old shield areas and the sedimentary belts surrounding them. They are followed by papers describing the European deposits mostly of Variscan age, and by similar deposits known from China being of Jurassic age. The volume is completed by two papers which do not fit exactly in the given scheme. A separate abstract was prepared for each of the 25 papers in this report

  11. Uranium deposits of Australia to 1975

    International Nuclear Information System (INIS)

    Spannari, S.

    1979-01-01

    This bibliography provides a retrospective account of Australian uranium deposits, particularly the unpublished materials in the Australian Capital Territory. Some abstracts are included. Occurrences, mineralogy, ore genesis, structural controls and the eonomic geology of uranium deposits are covered but the mining of uranium, exploration reports, surveys, environmental aspects and controversial materials are not

  12. Preliminary photointerpretation map of landslide and other surficial deposits of the Mount Diablo area, Contra Costa and Alameda Counties, California

    Science.gov (United States)

    Nilsen, Tor H.

    1971-01-01

    The map shows the distribution of landslide and other surficial deposits by presenting the writer's best judgement regarding the origins of the various parts of the present landscape. It is based completely on the interpretation of aerial photographs through a stereoscope, which permits a three-dimentional relief model of the ground surface to be seen, enables the geologist to study and interpret the origins of landforms with considerable ease. In fact, photointerpretation provides many advantages over both ground observations and laboratory studies of surficial materials in the mapping of surficial deposits, particularily for reconnaissance-type studies. Of course, better information can be provided when all aspects of the studyy are integrated. These preliminary photointerpretation maps are the inital stage of a continuing, more detailed study of surficial deposits in the Bay region, but they will hopefully provide map users with immediately useful information about the regional distribution of landslide and other surficial deposits

  13. The uranium deposits of Ontario

    International Nuclear Information System (INIS)

    Robertson, J.A.

    1981-01-01

    The principal types of uranium deposits in Ontario are carbonatites and fenites, alkalic volcanic rocks, pegiatites, calc-silicate rocks, pyritic quartz-pebble conglomerates, polymictic conglomerates and some pelitic rocks, and various 'pitchblende' deposits including late Precambrian unconformities, possibly late Precambrian diabase dikes, and other unconformities: carbonates, sandstones, lignites, and semi-pelitic rocks of middle and upper Precambrian age. Only red unzoned pegmatite and the pyritic quartz-pebble conglomerate have supported production. Ontario reasonably assured and estimated resources in the economic and subeconomic categories in 1977 amounted to 553 000 tonnes U, and 1977 production was 4000 tonnes U. Measured, indicated, and inferred resources in the Elliot Lake - Agnew Lake area are at least 400 000 tonnes U. The latter deposits are also a significant thorium resource. Geological features reflecting major changes in physics and chemistry are prime controls on distribution of uranium deposits. Geological province and subprovince boundaries, major faults, higher metamorphic grades, domain boundaries related to quartz monzonite batholiths, alkalic complexes, and the distribution of carbonate rocks are examples of such geological features

  14. Felsic magmatism and uranium deposits

    International Nuclear Information System (INIS)

    Cuney, Michel

    2014-01-01

    The strongly incompatible behaviour of uranium in silicate magmas results in its concentration in the most felsic melts and a prevalence of granites and rhyolites as primary U sources for the formation of U deposits. Despite its incompatible behavior, U deposits resulting directly from magmatic processes are quite rare. In most deposits, U is mobilized by hydrothermal fluids or ground water well after the emplacement of the igneous rocks. Of the broad range of granite types, only a few have U contents and physico-chemical properties that permit the crystallization of accessory minerals from which uranium can be leached for the formation of U deposits. The first granites on Earth, which crystallized uraninite, dated at 3.1 Ga, are the potassic granites from the Kaapval craton (South Africa) which were also the source of the detrital uraninite for the Dominion Reef and Witwatersrand quartz pebble conglomerate deposits. Four types of granites or rhyolites can be sufficiently enriched in U to represent a significant source for the genesis of U deposits: per-alkaline, high-K met-aluminous calc-alkaline, L-type peraluminous and anatectic pegmatoids. L-type peraluminous plutonic rocks in which U is dominantly hosted in uraninite or in the glass of their volcanic equivalents represent the best U source. Per-alkaline granites or syenites are associated with the only magmatic U-deposits formed by extreme fractional crystallization. The refractory character of the U-bearing minerals does not permit their extraction under the present economic conditions and make them unfavorable U sources for other deposit types. By contrast, felsic per-alkaline volcanic rocks, in which U is dominantly hosted in the glassy matrix, represent an excellent source for many deposit types. High-K calc-alkaline plutonic rocks only represent a significant U source when the U-bearing accessory minerals (U-thorite, allanite, Nb oxides) become metamict. The volcanic rocks of the same geochemistry may be

  15. Felsic magmatism and uranium deposits

    International Nuclear Information System (INIS)

    Cuney, M.

    2014-01-01

    Uranium strongly incompatible behaviour in silicate magmas results in its concentration in the most felsic melts and a prevalence of granites and rhyolites as primary U sources for the formation of U deposits. Despite its incompatible behaviour, U deposits resulting directly from magmatic processes are quite rare. In most deposits, U is mobilized by hydrothermal fluids or ground water well after the emplacement of the igneous rocks. Of the broad range of granite types, only a few have have U contents and physico-chemical properties that permit the crystallization of accessory minerals from which uranium can be leached for the formation of U deposits. The first granites on Earth which crystallized uraninite appeared at 3.1 Ga, are the potassic granites from the Kaapval craton (South Africa) which were also the source of the detrital uraninite for the Dominion Reef and Witwatersrand quartz pebble conglomerate deposits. Four types of granites or rhyolites can be sufficiently enriched in U to represent a significant source for the genesis of U deposits: peralkaline, high-K metaluminous calc-alkaline, L-type peraluminous ones and anatectic pegmatoids. L-type peraluminous plutonic rocks in which U is dominantly hosted in uraninite or in the glass in their volcanic equivalents represent the best U source. Peralkaline granites or syenites represent the only magmatic U-deposits formed by extreme fractional crystallization. The refractory character of the U-bearing minerals does not permit their extraction at the present economic conditions and make them unfavourable U sources for other deposit types. By contrast, felsic peralkaline volcanic rocks, in which U is dominantly hosted in the glassy matrix, represent an excellent source for many deposit types. High-K calc-alkaline plutonic rocks only represent a significant U source when the U-bearing accessory minerals [U-thorite, allanite, Nb oxides] become metamict. The volcanic rocks of the same geochemistry may be also a

  16. Formation and types of uranium deposits, uranium resources

    International Nuclear Information System (INIS)

    Dahlkamp, F.J.

    1975-01-01

    To begin with, the formation and origin of uranium deposits is described, and uranium deposits are classified into four basic categories. Of these, those that are of economic interest are described in detail with regard to their characteristic geological features, and their geographic distribution in the western world is outlined. The major facts and data regarding the geological and geochronological classification of these deposits and their size are given in tables and easy-to-interpret diagrams. (RB) [de

  17. Uranium deposits obtention for fission chambers

    International Nuclear Information System (INIS)

    Artacho Saviron, E.

    1972-01-01

    The obtention of uranium deposits of the required quality for small cylindrical fission chambers presents some difficulties. With the method of electroplating here described the uniformity, reproducibility and adherence of the obtained deposits were satisfactory. (Author) 6 refs

  18. Restoration of uranium solution mining deposits

    Energy Technology Data Exchange (ETDEWEB)

    Devries, F.W.; Lawes, B.C.

    1982-01-19

    A process is provided for restoring an ore deposit after uranium solution mining using ammonium carbonate leaching solutions has ceased. The process involves flushing the deposit with an aqueous solution of a potassium salt during which potassium ions exchange with ammonium ions remaining in the deposit. The ammonium containing flushing solution is withdrawn from the deposit for disposal.

  19. Restoration of uranium solution mining deposits

    International Nuclear Information System (INIS)

    Devries, F.W.; Lawes, B.C.

    1982-01-01

    A process is provided for restoring an ore deposit after uranium solution mining using ammonium carbonate leaching solutions has ceased. The process involves flushing the deposit with an aqueous solution of a potassium salt during which potassium ions exchange with ammonium ions remaining in the deposit. The ammonium containing flushing solution is withdrawn from the deposit for disposal

  20. Restoration of uranium solution mining deposits

    International Nuclear Information System (INIS)

    DeVries, F.W.; Lawes, B.C.

    1981-01-01

    Ammonium carbonates are commonly used as the lixiviant for in-situ leaching of uranium ores. However this leads to the deposition of ammonium ions in the uranium ore formation and the problem of ammonia contamination of ground water which may find its way into the drinking water supply. The ammonia contamination of the ore deposit may be reduced by injecting an aqueous solution of a potassium salt (carbonate, bicarbonate, halide, sulfate, bisulfate, persulfate, or monopersulfate) into the deposit after mining has ceased

  1. Uranium deposits in magmatic and metamorphic rocks

    International Nuclear Information System (INIS)

    1989-01-01

    The association of uranium with certain types of magmatic and metamorphic rocks is well known. They have consequently been explored and studied quite extensively. In recent years interest in them has been eclipsed by the discovery of larger, lower cost deposits in other geological environments. Nonetheless, magmatic and metamorphic rocks continue to be important sources of uranium and large areas of the Earth's crust with such rocks are prospective locations for additional discoveries. As future exploration and development could be more difficult the full importance of individual deposits may not be recognized until after many years of investigation and experience. In addition to being important host rocks, magmatic and metamorphic rocks have been of considerable interest to uranium geologists as they are considered to be important source rocks for uranium and thus can lead to deposits nearby in other environments. Furthermore, these rocks provide important information on the geochemical cycle of uranium in the Earth's crust and mantle. Such information can lead to identification of uranium provinces and districts and to a basic understanding of processes of formation of uranium deposits. The International Atomic Energy Agency convened a Technical Committee Meeting on Uranium Deposits in Magmatic and Metamorphic Rocks. The meeting was held in Salamanca, Spain, from 29 September to 3 October 1986. It was followed by a two day field trip to uranium deposits in the Ciudad Rodrigo and Don Benito areas. The meeting was attended by 48 participants from 22 countries. Two panels were organized for discussion of the following topics: (1) ore deposit genesis and characterization and (2) exploration and resource assessment. The technical papers together with the panel reports form this publication. The scope and variety of the papers included and the panel reports provide a good coverage of current knowledge and thinking on uranium in magmatic and metamorphic rocks

  2. Towards a genetic classification of uranium deposits

    International Nuclear Information System (INIS)

    Cuney, M.

    2009-01-01

    As the IAEA's uranium deposit classification is based on the deposit nature and morphology, some deposits which have been formed by very different genetic processes and located in very different geological environments, are grouped according to this classification. In order to build up a reliable genetic classification based on the mechanism at the origin of the formation of the deposit, the author presents the five main categories according to which uranium deposits can be classified: magmatic, hydrothermal, evapotranspiration, syn-sedimentary, and infiltration of meteoric water

  3. Mineralogical controls on uranium immobilization at Tono Uranium Deposit, Japan

    Science.gov (United States)

    Berke, M. A.; McKibben, M. A.; Arthur, R. C.; Ota, K.; Iwatsuki, T.

    2002-12-01

    The Tono uranium deposit, located in central Japan, is thought to have formed when oxidizing groundwater leached uranium from the underlying Toki Granite and transported it to the overlying host sedimentary formations where it precipitated under reducing conditions. Fission-track dating shows that this uranium mineralization took place ~10 million years ago and has remained immobilized despite episodes of sedimentation, uplift, subsidence, major faulting, and erosion. In order to understand the mineralogical controls on uranium immobilization, this study is gathering data on the mode of precipitation and adsorption of uranium within the various host lithologies. Optical petrography done on samples has shown a predominance of volcaniclastic deposits, containing glass shards within a fine-grained phyllosilicate matrix. Tephra that were formerly glass lack axiolitic devitrification textures and are altered to similar fine-grained mineralogy as in the matrix. X-ray diffraction data indicates that the majority of this fine-grained mineralogy is chlorite and the Mg, Ca smectite, saponite. Electron dispersive spectroscopy and back scattered electron data will create a map of the uranium concentrations and show any mineralogical affinities. Scanning and transmission electron microscope data will resolve the nature, crystallinity, and host sites of the uranium mineralization and help resolve the paragenesis in these tuffaceous rocks. This paper will address data gathered on samples across the host sedimentary formations and with depth to establish what mineralogical controls, if any, have influenced uranium precipitation and immobilization.

  4. Industrial types of uranium deposits in Kazakhstan

    International Nuclear Information System (INIS)

    Fyodorov, G.V.

    2001-01-01

    The main industrial uranium deposits of Kazakhstan that can be commercially mined, are located in two ore regions and are represented by two types of the uranium deposits. The first region is named Chu-Syrdarya (75.6% of total resources of Kazakhstan) and is located in the South of Kazakhstan and this one is the largest in the world among the regions of the deposits connected with the bed oxidation zone, localized in the permeable sediments and amenable for in-situ leach mining. The second region is named Kokshetau (16% of total resources) and is located in the North of Kazakhstan at the north edge of Kazak Shield and is characterized by the vein-stockwork type of deposit. Other industrial deposits (8.4% of total resources) are grouped in two regions that have been determined and are retained as reserves for economical and ecological reasons. These are: Pricaspian region with the organic phosphate type of uranium deposits; and Ili-Balkhash region with mainly the coal-uranium type. There are 44 industrial uranium deposits with resources ranging from 1000 t to 100000 t U and more in each of them, in all, in Kazakhstan. Seven of them are completely mined now. Total uranium resources in Kazakhstan are determined at 1670000 t U. (author)

  5. Data on nearshore wave process and surficial beach deposits, central Tamil Nadu coast, India.

    Science.gov (United States)

    Joevivek, V; Chandrasekar, N

    2017-08-01

    The chronicles of nearshore morphology and surficial beach deposits provide valuable information about the nature of the beach condition and the depositional environment. It imparts an understanding about the spatial and temporal relationship of nearshore waves and its influence over the distribution of beach sediments. This article contains data about wave and sediment dynamics of the ten sandy beaches along the central Tamil Nadu coast, India. This present dataset comprises nearshore wave parameters, breaker wave type, beach morphodynamic state, grain size distribution and weight percentage of heavy and light mineral distribution. The dataset will figure out the beach morphology and hydrodynamic condition with respect to the different monsoonal season. This will act as a field reference to realize the coastal dynamics in an open sea condition. The nearshore entities were obtained from the intensive field survey between January 2011 and December 2011, while characteristics of beach sediments are examined by the chemical process in the laboratory environment.

  6. Data on nearshore wave process and surficial beach deposits, central Tamil Nadu coast, India

    Directory of Open Access Journals (Sweden)

    V. Joevivek

    2017-08-01

    Full Text Available The chronicles of nearshore morphology and surficial beach deposits provide valuable information about the nature of the beach condition and the depositional environment. It imparts an understanding about the spatial and temporal relationship of nearshore waves and its influence over the distribution of beach sediments. This article contains data about wave and sediment dynamics of the ten sandy beaches along the central Tamil Nadu coast, India. This present dataset comprises nearshore wave parameters, breaker wave type, beach morphodynamic state, grain size distribution and weight percentage of heavy and light mineral distribution. The dataset will figure out the beach morphology and hydrodynamic condition with respect to the different monsoonal season. This will act as a field reference to realize the coastal dynamics in an open sea condition. The nearshore entities were obtained from the intensive field survey between January 2011 and December 2011, while characteristics of beach sediments are examined by the chemical process in the laboratory environment.

  7. Lake Way uranium deposit, Wiluna, Western Australia

    International Nuclear Information System (INIS)

    French, R.R.; Allen, J.H.

    1984-01-01

    The Lake Way uranium deposit, 16 km southeast of Wiluna, is in an area of granites with around 12 ppm uranium, and greenstones, near the edge of the playa Lake Way which is the drainage base for a large ancient drainage system. The deposit is carnotite in calcrete and is below or near the water table in areas of high salinity. The deposit has over 5000 tonnes U 3 O 8 , averages 1,55 m thick and is at depth of 0-10 meters. The deposit was discovered by an airborne radiometric survey. (author)

  8. Precambrian uranium deposits as a possible source of uranium for the European Variscan deposits

    International Nuclear Information System (INIS)

    Mineeva, I.G.; Klochkov, A.S.

    2002-01-01

    The Precambrian uranium deposits have been studied on the territory of Baltic and Ukrainian shields. The primary Early Proterozoic complex Au-U deposits originated in granite-greenstone belts as a result of their evolution during continental earth crust formation by prolonged rift genesis. The greenstone belts are clues for revealing ancient protoriftogenic structures. The general regularities of uranium deposition on Precambrian shields are also traceable in Variscan uranium deposits from the Bohemian massif. The Variscan period of uranium ore formation is connected with a polychronous rejuvenation of ancient riftogenous systems and relatively younger processes of oil and gas formation leading to the repeated mobilization of U from destroyed Proterozoic and Riphean uranium deposits. (author)

  9. Uranium deposits of the world. Europe

    Energy Technology Data Exchange (ETDEWEB)

    Dahlkamp, Franz J.

    2016-07-01

    Uranium Deposits of the World, in three volumes, comprises an unprecedented compilation of data and descriptions of the uranium regions in Asia, USA, Latin America and Europe structured by countries. With this third, the Europe volume, Uranium Deposits of the World presents the most extensive data collection of the set. It covers about 140 uranium regions in more than 20 European countries with nearly 1000 mentioned uranium deposits. Each country and region receives an analytical overview followed by the geologically- and economically-relevant synopsis of the individual regions and fields. The presentations are structured in three major sections: (a) location and magnitude of uranium regions, districts, and deposits, (b) principal features of regions and districts, and (c) detailed characteristics of selected ore fields and deposits. This includes sections on geology, alteration, mineralization, shape and dimensions of deposits, isotopes data, ore control and recognition criteria, and metallogenesis. Beside the main European uranium regions, for example in the Czech Republic, Eastern Germany, France, the Iberian Peninsula or Ukraine, also small regions an districts to the point of singular occurrences of interest are considered. This by far the most comprehensive presentation of European uranium geology and mining would not be possible without the author's access to extensive information covering the countries of the former Eastern Bloc states, which was partly not previously available. Abundantly illustrated with information-laden maps and charts throughout, this reference work is an indispensable tool for geologists, mining companies, government agencies, and others with an interest in European key natural resources. A great help for the reader's orientation are the substantial bibliography of uranium-related publications and the indices, latter containing about 3900 entries in the geographical part alone. The three volumes of Uranium Deposits of the

  10. Migration and fixation of Uranium in the surficial environment. Case histories and applications to geochemical exploration

    International Nuclear Information System (INIS)

    Pradier, B.

    Uranium geochemistry is studied in three different test areas: surface waters, sediments, and isohumic soils. Using data from the WATEQ-type thermodynamic model the state of uranium in sampled waters is examined. Uranium is present in the oxidized state U 6 , as uranyl ion UO 2 ++ , complexed by the HPO 4 -- ion and CO 3 ion. Estimated residual uranium values, have shown the very probable existence of a non mineral support for uranium in solution, probably uranyl-fulvates. Uranium in stream-sediments is preferentially located in the fine-grained fractions. The bearing phases of the geochemical uranium, identified in the fine-grained fractions, are mainly composed by amorphous or cryptocrystallized iron oxi-hydroxide, and accessorily by fulvic (and humic) acids. Ferric phases support 60 to 75% of the total uranium. In the isohumic soils, the uranium mobility depends on the existence of highly reactive and poorly evoluted organic compounds, and amorphous or cryptocristallised ferric phases located in the first centimeters of the upper horizon. The recognition of the factors governing uranium behavior in the superficial media requires the preliminary definition of the uranium expression in waters, and that of its bearing phases in soils and stream-sediments. High uranium content in waters are not significant if related to high HCO 3 - and/or PO 4 3- content, and doubtlessly to high dissolved organic carbon content. The interest of residual uranium mapping in stream-sediment geochemistry is underlined. Data are computed by difference between natural value and the corresponding estimated value, calculated by regression taking in account the adsorbant phases content of each sample [fr

  11. The Nopal 1 Uranium Deposit: an Overview

    Science.gov (United States)

    Calas, G.; Allard, T.; Galoisy, L.

    2007-05-01

    The Nopal 1 natural analogue is located in the Pena Blanca uranium district, about 50 kms north of Chihuahua City, Mexico. The deposit is hosted in tertiary ignimbritic ash-flow tuffs, dated at 44 Ma (Nopal and Colorados formations), and overlying the Pozos conglomerate formation and a sequence of Cretaceous carbonate rocks. The deposit is exposed at the ground surface and consists of a near vertical zone extending over about 100 m with a diameter of 40 m. An interesting characteristic is that the primary mineralization has been exposed above the water table, as a result of the uplift of the Sierra Pena Blanca, and subsequently oxidized with a remobilization of hexavalent uranium. The primary mineralization has been explained by various genetic models. It is associated to an extensive hydrothermal alteration of the volcanic tuffs, locally associated to pyrite and preserved by an intense silicification. Several kaolinite parageneses occur in fissure fillings and feldspar pseudomorphs, within the mineralized breccia pipe and the barren surrounding rhyolitic tuffs. Smectites are mainly developed in the underlying weakly welded tuffs. Several radiation-induced defect centers have been found in these kaolinites providing a unique picture of the dynamics of uranium mobilization (see Allard et al., this session). Another evidence of this mobilization is given by the spectroscopy of uranium-bearing opals, which show characteristic fluorescence spectra of uranyl groups sorbed at the surface of silica. By comparison with the other uranium deposits of the Sierra Pena Blanca and the nearby Sierra de Gomez, the Nopal 1 deposit is original, as it is one of the few deposits hving retained a reduced uranium mineralization.

  12. Uranium deposit of Bauzot (Saone et Loire)

    International Nuclear Information System (INIS)

    Carrat, G.H.

    1956-01-01

    The best known of the uranium ore deposits of the Morvan (a province of France) is in the form of a bundle of quartz-fluor lodes with pitchblende and B.P.G.C. ore. The pitchblende seems to have been deposited at different time in respect to the formation of the gangue minerals, but generally it is ore of the first-formed. The main concentrations of ore are always in the vicinity of dykes of basic crystalline rocks. (author) [fr

  13. World Distribution of Uranium Deposits (UDEPO) with uranium deposit classification. 2009 ed

    International Nuclear Information System (INIS)

    2009-10-01

    The World Distribution of Uranium Deposits (UDEPO) database provides general, technical and geological information, including references, about the worldwide uranium deposits. UDEPO has been published on the internet which allows the users to register freely and to work with datasets (http://www-nfcis.iaea.org). The UDEPO web site is designed to allow users to retrieve data sets on a variety of deposit related topics ranging from specific information on individual uranium deposits to statistical information on uranium deposits worldwide. The basic building blocks for the UDEPO database are the more than 900 individual deposits for which information is available in the database. The database is arranged in a relational database format which has one main table and a number of associated tables. Structured nature of the database allows filtering and querying the database in more systematic way. The web site provides filtering and navigation to the data from the database. It has also a statistical tool which provides summary information on number of deposits and uranium resources by type and status, and by country and status. In this respect and with regard to the data presented, the UDEPO database is a unique database which provides freely accessible information on worldwide uranium deposits. Although a great effort is spent to have complete and accurate database, the users should take into consideration that there still might be missing or outdated data for individual deposits due to the rapid changes in the uranium industry due to the new exploration works which are ongoing everyday. This document and its supplementary CD-ROM represent a snapshot of the status of the database as of the end of 2008. However, the database is being continuously updated and the latest updates and additions can be accessed from the database web site (http://wwwnfcis.iaea.org)

  14. Uranium and thorium deposits of Northern Ontario

    International Nuclear Information System (INIS)

    Robertson, J.A.; Gould, K.L.

    1983-01-01

    This, the second edition of the uranium-thorium deposit inventory, describes briefly the deposits of uranium and/or thorium in northern Ontario, which for the purposes of this circular is defined as that part of Ontario lying north and west of the Grenville Front. The most significant of the deposits described are fossil placers lying at or near the base of the Middle Precambrian Huronian Supergroup. These include the producing and past-producing mines of the Elliot Lake - Agnew Lake area. Also included are the pitchblende veins spatially associated with Late Precambrian (Keweenawan) diabase dikes of the Theano Point - Montreal River area. Miscellaneous Early Precambrian pegmatite, pitchblende-coffinite-sulphide occurrences near the Middle-Early Precambrian unconformity fringing the Lake Superior basin, and disseminations in diabase, granitic rocks, alkalic complexes and breccias scattered throughout northern Ontario make up the rest of the occurrences

  15. Latest Pleistocene and Holocene surficial deposits and landforms of Yosemite Valley, California

    Science.gov (United States)

    Haddon, E. K.; Stock, G. M.; Booth, D. B.

    2016-12-01

    Field studies on the surficial geology and geomorphology of Yosemite Valley since the 1870's formed an early basis for our understanding of Quaternary landscape evolution in the central Sierra Nevada. These landmark studies described the erosional origin of Yosemite's iconic scenery, but left details of the latest Pleistocene and Holocene sedimentary record for later investigation. We combined mapping of deposits and landforms with geochronology to reconstruct the geomorphic evolution of Yosemite Valley since the 15 ka retreat of the Last Glacial Maximum (LGM) valley glacier. We document a sustained period of relative landscape stability, characterized by valley-bottom aggradation of glacial till, fluvial sediments, and lacustrine silts, as well as valley-margin accumulation of talus and fan alluvium. Recessional moraines, episodically emplaced rock avalanches, and alluvial fans impeded surface flow and controlled the local base level. This predominantly aggradational regime then shifted to incision in the earliest Holocene, likely due to a diminishing supply of glacial sediment, and created a flight of fluvial terraces inset by up to 9 m. The volume of fringing talus and fan alluvium in comparison with fluvial terrace sequences emphasizes the importance of valley-wall erosion as a sediment source. Cosmogenic 10Be exposure ages from rock avalanche boulders and 14C charcoal ages from deltaic sequences and inset fluvial gravels suggest variable rates of Holocene river incision. Although some incision events likely record local base level changes at the El Capitan LGM recessional moraine, the presence of perched, well-developed outwash terraces downstream indicates a more regional climatic forcing. These findings, including the depositional record of land-use disturbances over the past two centuries, help illuminate the geologic evolution of this celebrated landscape and inform ongoing river-restoration work.

  16. Uranium deposits in Grant County, New Mexico

    Science.gov (United States)

    Granger, Harry C.; Bauer, Herman L.; Lovering, Tom G.; Gillerman, Elliot

    1952-01-01

    The known uranium deposits of Grant county, N. Mex., are principally in the White Signal and Black Hawk districts. Both districts are within a northwesterly-trending belt of pre-Cambrian rocks, composed chiefly of granite with included gneisses, schists, and quartzites. Younger dikes and stocks intrude the pre-Cambrian complex. The White Signal district is on the southeast flanks of the Burro Mountains; the Black Hawk district is about 18 miles northwest of the town of White Signal. In the White Signal district the seconday uranium phosphates--autunite and torbernite--occur as fracture coatings and disseminations in oxidized parts of quartz-pyrite veins, and in the adjacent mafic dikes and granites; uraniferous limonite is common locally. Most of the known uraniferous deposits are less that 50 feet in their greatest dimension. The most promising deposits in the district are on the Merry Widow and Blue Jay claims. The richest sample taken from the Merry Widow mine contained more than 2 percent uranium and a sample from the Blue Jay property contained as much as 0.11 percent; samples from the other properties were of lower grade. In the Black Hawk district pitchblende is associated with nickel, silver, and cobalt minerals in fissure veins. The most promising properties in the Black Hawk district are the Black Hawk, Alhambra, and Rose mines. No uranium analyses from this district were available in 1951. There are no known minable reserves of uranium ore in either district, although there is some vein material at the Merry Widow mine of ore grade, if a market were available in the region.

  17. Discussion on the genesis of Zhongchuan uranium deposit

    International Nuclear Information System (INIS)

    Zhang Yulong; Zhang Chengzhong

    2008-01-01

    Through elaborating the geological setting, deposit and orebody geological charactors and hydrological features, the ore controlling factors are analysed and the genesis of Zhongchuan uranium deposit is discussed in the way of deposit occurrence, mineral asembleage and matalization ages. It is believed that uranium deposit was formed under the regional uplifting background with the exogenous mechanism and its genesis belongs to surface leaching. (authors)

  18. Geological-genetic classification for uranium deposits

    International Nuclear Information System (INIS)

    Terentiev, V.M.; Naumov, S.S.

    1997-01-01

    The paper describes a system for classification uranium deposits based on geological and genetic characteristics. The system is based on the interrelation and interdependence of uranium ore formation processes and other geological phenomena including sedimentation, magmatism and tectonics, as well as the evolution of geotectonic structures. Using these aspects, deposits are classified in three categories: endogenic - predominately hydrothermal and hydrothermal-metasomatic; exogenic - sedimentary diagenetic, biogenic sorption, and infiltrational; and polygenetic or composite types. The latter complex types includes: sedimentary/metamorphic and metamorphic and sedimentary/hydrothermal, where different ore generating processes have prevailed over a rock unit at different times. The 3 page classification is given in both the English and Russian languages. (author). 3 tabs

  19. The Palmottu Analogue Project, Progress Report 1993. The behaviour of natural radionuclides in and around uranium deposits, Nr. 7

    International Nuclear Information System (INIS)

    Ruskeeniemi, T.; Blomqvist, R.; Suksi, J.; Niini, H.

    1994-01-01

    The report gives a summary of the results of investigations carried out in 1993 at the Palmottu natural analogue study site, which comprises a small U-Th mineralization in Nummi-Pusula, southwestern Finland. Additionally, the report includes several separate articles dealing with various aspects of the Palmottu Analogue Project: (1) 3-dimensional model of fracture zones, (2) redox chemistry of uranium in groundwater, (3) humic substances in groundwater, (4) uranium mineralogy, (5) importance of selective extractions in uranium migration studies, (6) modelling of matrix diffusion, and (7) uranium in surficial deposits. The Palmottu Analogue Project aims at a more profound understanding of radionuclide transport processes in fractured crystalline bedrock. The essential factors controlling transport are groundwater flow and interaction between water and rock. Accordingly, the study includes (1) structural interpretations partly based on geophysical measurements, (2) hydrological studies including hydraulic drill-hole measurements, (3) flow modelling, (4) hydrogeochemical characterization of groundwater, uranium chemistry and colloid chemistry, (5) mineralogical studies, (6) geochemical interpretation and modelling, (7) studies on mobilization and retardation of uranium, and (8) modelling of uranium series data. Paleohydrogeological aspects are of special interest, due to the anticipated future glaciation of the Fennoscandian Shield. Surficial sediments and waters are studied to gain information on postglacial migration in the overburden. (orig.)

  20. A geostatical model for USA uranium deposits

    International Nuclear Information System (INIS)

    Drew, M.W.

    1979-01-01

    Evidence exists which suggests that the frequency distributions of both grade and size of metal deposits may be well approximated by lognormal distribution functions. Using data on presently viable deposits and a simplified function which links production cost to deposit grade and size, a bivariate lognormal deposit grade/size distribution may be calibrated for a given geological environment. Exploration is introduced by assuming that the proportion discovered of the potential uranium reserve available at or below a given production can be represented by a fraction of the average deposit size and the limit exploration expenditure. As output, the model derives estimates of total reserves linked to maximum production costs and to exploration expenditure where the latter may be expressed either as expenditure per lb of mineral discovered or as a given percentage of operating profit. Reserve/price functions have been derived for the USA based on USAEC data. Tentative conclusions which may be drawn from the results are: (1) Assuming that a similar proportion of profits continues to be allocated to exploration in the future, then the USA should be able to meet its own national demand for uranium up to the end of the century (say 2 M tons U) at prices up to US$35/lb U 3 O 8 (1.1.75$ values). (2) If instead of all exploration being funded from a fixed maximum proportion of mining company profits, consumers were to fund additional exploration separately, then it is possible that the total unit cost of uranium to the consumers would thereby be reduced. It should be stressed that these conclusions are tentative and are only as reliable as the input data and assumptions of the model. In particular no account is taken of commercial or political forces which could artificially restrict supplies or raise prices. The model should be regarded as a first attempt and is offered as a basis for discussion leading to further development. (author)

  1. Study on the classification of uranium deposits in China (Ⅱ)

    International Nuclear Information System (INIS)

    Tong Hangshou

    2014-01-01

    Study on the changes of the deposit classification remains one important part in uranium metallogenesis, and much attention has been paid by the uranium geologists. Study on the deposit classification in China from the introduction to the development has already experienced nearly 60 years and a large amount of information has been accumulated and need to summarize. Much attention has been paid on the study on the uranium deposit classification by the author since 1960's, more than 80 examples of uranium deposit classifications have been accumulated, in which about 50 examples are uranium deposit types schemes in China. much inspiration has been obtained. By summarizing and rethinking the study on the uranium deposit types in China, a brand-new classification scheme has been raised, which will be divided into two parts to discuss in brief, this paper is the first part. (author)

  2. Study on the classification of uranium deposits in China (Ⅰ)

    International Nuclear Information System (INIS)

    Tong Hangshou

    2014-01-01

    Study on the changes of the deposit classification remains one important part in uranium metallogenesis, and much attention has been paid by the uranium geologists. Study on the deposit classification in China from the introduction to the development has already experienced nearly 60 years and a large amount of information has been accumulated and need to summarize. Much attention has been paid on the study on the uranium deposit classification by the author since 1960's, more than 80 examples of uranium deposit classifications have been accumulated, in which about 50 examples are uranium deposit types schemes in China. much inspiration has been obtained. By summarizing and rethinking the study on the uranium deposit types in China, a brand-new classification scheme has been raised, which will be divided into two parts to discuss in brief, this paper is the first part. (author)

  3. Geology and Mineralogy of Uranium Deposits from Mount Isa, Australia: Implications for Albitite Uranium Deposit Models

    Directory of Open Access Journals (Sweden)

    Nick Wilson

    2013-06-01

    Full Text Available New geological, bulk chemical and mineralogical (QEMSCAN and FEG-EPMA data are presented for albitite-type uranium deposits of the Mount Isa region of Queensland, Australia. Early albitisation of interbedded metabasalt and metasiltstone predated intense deformation along D2 high strain (mylonite zones. The early sodic alteration paragenetic stage includes albite, riebeckite, aegirine, apatite, zircon and magnetite. This paragenetic stage was overprinted by potassic microveins, containing K-feldspar, biotite, coffinite, brannerite, rare uraninite, ilmenite and rutile. An unusual U-Zr phase has also been identified which exhibits continuous solid solution with a uranium silicate possibly coffinite or nenadkevite. Calcite, epidote and sulphide veinlets represent the latest stage of mineralisation. This transition from ductile deformation and sodic alteration to vein-controlled uranium is mirrored in other examples of the deposit type. The association of uranium with F-rich minerals and a suite of high field strength elements; phosphorous and zirconium is interpreted to be indicative of a magmatic rather than metamorphic or basinal fluid source. No large intrusions of appropriate age outcrop near the deposits; but we suggest a relationship with B- and Be-rich pegmatites and quartz-tourmaline veins.

  4. Investigation into the Origin and Character of Surficial Sedimentary Deposits at the Midshore Regional Solid Waste Facility near Easton, Maryland

    Science.gov (United States)

    Smoot, Joseph P.; Newell, Wayne L.; DeJong, Benjamin D.

    2009-01-01

    A temporary exposure at the Midshore Regional Solid Waste Facility near Easton, MD, provided an opportunity to document the characteristics of the complex assemblage of surficial facies in that area. This unusually large cross section allowed interpretation of the changing processes that shaped the landscape in response to climate change through the late Pleistocene. Eight stratigraphic units were recognized: (1) gray, fossiliferous, muddy silt of the marine Miocene Choptank Formation; (2) coarse, crossbedded conglomerate of the late Miocene to Pliocene fluvial Pensauken Formation; (3) bioturbated muddy conglomerate interpreted as deposits of small colluvial fans; (4) pebbly, quartzose sand overlying a planar erosional surface reflecting a marine transgression; (5) irregular pods and lenses of sand and gravel deformed into bowl-shaped folds and faulted, which are interpreted as wind deposits over a semipermanent snow cover (niveo-aeolian deposits); (6) crossbedded sand and conglomerate with abundant mud partings indicating tidal influences on sinuous stream channels; (7) heavily bioturbated silt and sand with abundant root casts and flattened vesicles interpreted as aeolian loess deposits in marshy fens; and (8) pebbly sand and mud with scattered boulders and cobbles that reflect modern infill of the excavation by the operators. Soils formed on units 3, 4, and 7. Superimposed on units 4, 5, and 7 is evidence of deep freezing and permafrost development and subsequent thermokarst development after thawing, which includes large, complexly filled wedge-shaped cracks, deformed bedding and faults, fluid-injection structures, and spherical blobs of sand and mud. Each of the stratigraphic units has irregular distributions and lateral changes. The results of this study provide a unique insight into the geometry of surficial deposits that will help facilitate mapping of units, interpretation of cored intervals, and understanding of ground-penetrating radar profiles. The

  5. Origin of ores of endogeneous uranium ore deposits

    International Nuclear Information System (INIS)

    Kasanskij, V.I.; Laverov, N.P.; Tugarinov, A.I.

    1976-01-01

    The consideration mainly includes those endogenous uranium ore deposits of which more exact data are available, such as precambrian ones in areas of proto-activated old platforms, deposits of palaeozoic fold areas, and mesozoic deposits in areas of tectonic-magnetic activation. Their genesis and typical characters are mentioned and conclusions on the general distribution of the deposits are drawn. (author)

  6. Nopal I uranium deposit: A study of radionuclide migration

    International Nuclear Information System (INIS)

    Wong, V.; Anthony, E.; Goodell, P.

    1996-01-01

    This summary reports on activities of naturally-occurring radionuclides for the Nopal I uranium deposit located in the Pena Blanca Uranium District, Chihuahua, Mexico. Activities were determined using gamma-ray spectroscopy. In addition, data reduction procedures and sample preparation (for Rn retention) will be discussed here. Nopal I uranium deposit has been identified as one of the most promising sites for analogue studies to the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. The objective of this research is to study the potential for radionuclide migration by testing whether any portion of the deposit is in secular equilibrium

  7. Induced polarization and electromagnetic field surveys of sedimentary uranium deposits

    International Nuclear Information System (INIS)

    Campbell, D.L.; Smith, B.D.

    1985-01-01

    Induced polarization (IP) and electromagnetic (EM) geophysical surveys were made over three areas of sedimentary uranium deposits in the western United States. The EM techniques were sometimes useful for investigating general structural settings, but not for finding uranium deposits per se. IP techniques were useful to help pinpoint zones of disseminated pyrite associated with the uranium deposits. In one case no clear differences were seen between the IP signatures of oxidized and reduced ground. Spectral (multi-frequency) IP showed no particular advantages over conventional IP for exploration applications. A sediment mineralization factor is introduced comparable to the ''metal factor'' used to detect porphyry copper mineralization. (author)

  8. Metallogenetic condition and mineralization characteristics of uranium deposit No.114

    International Nuclear Information System (INIS)

    Niu Lin; Ma Fei; Yang Wanjin

    1988-01-01

    Deposit No 114 is one of the typical carbonate-type uranium deposits, that are widely distributed in South China. In this paper formational environment of host rock, wall-rock alteration, sulfur, oxygen, carbon isotopes, mineralization temperatures, ore compsitions were studied. Based on the U-Pb isotopic research three mineralization stages in deposit No 114 were established, namely 104 Ma, 61 Ma and 11 Ma. It is suggested, that the deposit No 114 is a polygenetic deposit formed primarily by supergene leaching and hydrothermal reworked. The uranium deposit has multi-sources, the main uranium source of which is from the granite body situated nearby. According to metallogenetic characteristics the authors suggest the favourable geological exploration guides for this kind of ore deposits

  9. The uranium deposit at Kvanefjeld, the Ilimaussaq intrusion, South Greenland

    International Nuclear Information System (INIS)

    Soerensen, H.; Rose-Hansen, J.; Leth Nielsen, B.; Loevborg, L.; Soerensen, E.; Lundgaard, T.

    1974-01-01

    The uranium-thorium deposits is located in part of an alkaline intrusion consisting of peralkaline, agpaitic nepheline syenites. The radioactive minerals are steenstrupine, uranium-rich monazite, thorite and pigmentary material. The radio-element content varies from 100 to 3000 ppm U and 300 to 15000 ppm Th. Reasonably assured ore in the main area with a grade of 310 ppm is calculated to 5800 metric tons of uranium in 18.6 million metric tons of ore. Estimated additional reserves with a grade of 292 ppm U are 29.4 million tons of ore with 8700 tons of uranium and 3.5 million tons of ore with a grade of 350 ppm yielding 1200 tons of uranium. Estimates of amounts of thorium ore are 2.6 times those of uranium. A method of recovery of the uranium based on sulphating roasting and subsequent leaching with water is described. (author)

  10. Aeromagnetic gradient survey used in sandstone type uranium deposits prospecting

    International Nuclear Information System (INIS)

    Li Xiaolu; Chang Shushuai

    2014-01-01

    The principle, advantage and data processing of aeromagnetic gradient survey approach is introduced in this paper which was used in sandstone type uranium deposits prospecting to study the shallow surface faults, uranium ore-forming environment and depth of magnetic body, which proved to be a good results. (authors)

  11. Isotope geochemical characteristics in uranium deposits in China

    International Nuclear Information System (INIS)

    Li Yaosong

    1995-06-01

    Most of the uranium deposits in China occurs in geological setting of the geosynclinal folded zone and the mobile region, and hydrothermal uranium deposits are dominant position. The late Mesozoic and the early Cenozoic (Cretaceous-Tertiary) are the major metallogenetic epochs for uranium deposits, which are characterized by relative concentration in time and space. On the basis of principle of uranium-lead isotope system evolution, the viewpoint of uranium mobilized mineralization has been proved; the sources of uranium is distinguished and metallogenetic prospect is evaluated on the basis of uranium loss and anomalous initial lead from geological bodies. Scientific research on light stable isotope geochemistry indicates that the isotopic composition of sulphur and carbon in ore-forming solution relate to nature of ore-bearing rocks, and the character of 'draw on local resources' displays very clearly; hydrogen and oxygen isotope geochemistry indicates that the source of ore-forming solution for hydrothermal vein-type uranium deposits in China may be divided into three cases, namely mix of magmatic hydrothermal solution and atmospheric water, main origin from atmospheric water, and mix of metamorphic water and atmospheric water. (10 tabs., 4 figs.)

  12. The characteristics of uranium mineralization and genesis of Nuheting uranium deposit in Erlian basin Inner Mongolian

    International Nuclear Information System (INIS)

    Niu Lin; Huang Shutao; Yang Guisheng

    1995-10-01

    The Nuheting uranium deposit is located at the northern margin of Erlian basin in Inner Mongolian. Uranium mineralizations are localized in the Erlian formation of upper Cretaceous system. Main types of ore are argillite, argillaceous siltstone and argillaceous graywacke. There are 3 main mineral associations in places with uranium: uranium-gypsum-celestione; uranium-pyriteorganic matter; uranium-pyrite, marcasite and other metalliferous sulfides. Uranium is mainly adsorbed and pitchblende in minor amount can also be found. The formation of economic uranium orebody is related with migration of oil and gas, because there are organic matter of aromatic hydrocarbon and moving hydrocarbon in uranium ore. The U-Pb isotopic ages of ore and pitchblende are 85, 40 and 10 Ma, which indicate that Nuheting uranium deposit was formed in long-term geological process and principally underwent three main stages: Sedimentary diagenesis; migration of oil and gas; and stage of supergene reworking. Therefore, the deposit should be classified as polygenetic type. (9 tabs.; 3 figs)

  13. Digitization of uranium deposit information in basin. A new strategy of ISL sandstone-type uranium deposits exploration

    International Nuclear Information System (INIS)

    Tan Chenglong

    2006-01-01

    The discovered ISL sandstone-type uranium deposits in the entire world are mostly blind deposits, many of them occur in bleak desert, gobi desert, and semi-hilly land area. Exploration methods for these deposits mainly depend on great and systematic drilling. There are many large-medium size Meso-Cenozoic sedimentary basins in northern China, and over twenty of them are thick overburden basins which are mostly the virgin land for ISL sandstone-type uranium deposit. Due to the comprehensive national power, geological background, uranium exploration ability, great and systematic drilling is not favorable for prospecting ISL sandstone-type uranium deposit in China. According to the exploration and prospecting experiences for mineral ore bodies at home and abroad, uranium information mapping based on geochemical survey of the basins is a new strategy for ISL sandstone-type uranium deposits. It is an economic, practical, fast and effective method, and has been manifested by the performing information digitization for oil and gas resources, gold mineral resources in China and the mapping of uranium information for whole Europe continent. (authors)

  14. Principal types of precambrian uranium-gold deposits and their metallogenetic characteristics in China

    International Nuclear Information System (INIS)

    Liang Liang; Zhong Zhiyun.

    1988-01-01

    Principal types of Precambrian uranium-gold deposits are follows: paleo-conglomerate uranium-deposit, stratified or strata-bound uranium-gold deposit, unconformity-related uranium deposit (no or seldem gold) and greenstone gold deposit. The main types of gold deposits in China is greenstone one which is characterized by later age, high grade metamorphism and a large time difference between diagenesis of host rocks and gold metallogenesis. Gold deposits are spatially distributed in the uplift area, whereas uranium deposits are distributed in the downfaulted belt. Furthermore, both uranium and gold deposits are controlled by regional fractures

  15. Uranium

    International Nuclear Information System (INIS)

    Cuney, M.; Pagel, M.; Leroy, J.

    1992-01-01

    First, this book presents the physico-chemical properties of Uranium and the consequences which can be deduced from the study of numerous geological process. The authors describe natural distribution of Uranium at different scales and on different supports, and main Uranium minerals. A great place in the book is assigned to description and classification of uranium deposits. The book gives also notions on prospection and exploitation of uranium deposits. Historical aspects of Uranium economical development (Uranium resources, production, supply and demand, operating costs) are given in the last chapter. 7 refs., 17 figs

  16. The uranium ore deposits in Ciudad Rodrigo Phyllites. about the possibility of new deposits

    International Nuclear Information System (INIS)

    Mingarro Martin, E.; Marin Benavente, C.

    1969-01-01

    The main features of the genesis of uranium deposits of the Fe mine type, are discussed in this paper. Pitchblende ore is related with phyllites bearing organic material and with geomorphological level, fossilized by eocene sediments. As a result, new uranium ore deposits are possible under Ciudad Rodrigo tertiary basin, tertiary cover depth being little more than three hundred feet. (Author)

  17. PROCESS FOR THE RECOVERY AND PURIFICATION OF URANIUM DEPOSITS

    Science.gov (United States)

    Carter, J.M.; Kamen, M.D.

    1958-10-14

    A process is presented for recovering uranium values from UCl/sub 4/ deposits formed on calutrons. Such deposits are removed from the calutron parts by an aqueous wash solution which then contains the uranium values in addition to the following impurities: Ni, Cu, Fe, and Cr. This impurity bearing wash solution is treated with an oxidizing agent, and the oxidized solution is then treated with ammonia in order to precipitate the uranium as ammonium diuranate. The metal impurities of iron and chromium, which form insoluble hydroxides, are precipitated along with the uranium values. The precipitate is separated from the solution, dissolved in acid, and the solution again treated with ammonia and ammonium carbonate, which results in the precipitation of the metal impurities as hydroxides while the uranium values remain in solution.

  18. Metallogenesis of rich uranium deposits in Xiangshan hydrothermal ore field

    International Nuclear Information System (INIS)

    Wen Zhijian; Du Letian; Liu Zhengyi

    2001-01-01

    Xiangshan Uranium Ore field located in Jiangxi Province, south of China, is one of the largest volcanogenic hydrothermal uranium ore fields in China. There are apparent difference in uranium metallogenesis between low-grade deposits and rich uranium ones (U > 0.3%, especially U > 1%) in Xiangshan hydrothermal uranium ore field. The special hydrothermal solution with higher content of P, Ti, K elements is a geochemical controlling factor for rich uranium mineralization. Fluorine is an important transporter for uranium migration in hydrothermal system, however, it plays a limited function of uranium mineralization. In fact, uranium and thorium are migrated and precipitated through some complicated processes including alkali-metasomatism, co-migration, colloid co-precipitation with phosphate minerals and gas reduction etc., which has been proved by field investigation, experiments and a number of analysis. The deeper the orebodies are located, the higher the grade of ore is. The reasonable explanation is as following: (1) the contents of P, Ti, F, K. U and reducing gases in hydrothermal solution increase along with deepness; (2) The temperature and pressure in deep are higher than that on shallower parts. All the factors mentioned above together play active roles in uranium enrichment. Some suggestions for further exploitation and exploration in Xiangshan area have been put forward

  19. Uranium deposits: Main types and concepts for detection

    International Nuclear Information System (INIS)

    Mashkovtsev, G.A.; Kislyakov, Ya.M.; Miguta, A.K.; Modnikov, I.S.; Shchetochkin, V.N.

    1997-01-01

    This paper presents a classification of uranium deposits as a basis for developing an optimal exploration strategy for discovering deposits with favorable characteristics for low production cost. The classification is based on endogenic and exogenic sub-classes both of which are subdivided to synegenetic and epigenetic groups. The tectonic setting is also taken into consideration. Following description of the economic and geological types of deposits, the factors governing the formation of the deposits is given. (author). 2 figs, 2 tabs

  20. Uranium metallogenic model related to CO2 and hydrocarbon in granite type uranium deposits

    International Nuclear Information System (INIS)

    Ou Guangxi; Chen Anfu; Cui Jianyong; Xu Yinhuan; Wang Chunhua; Xu Yan

    2001-01-01

    The report is concerned with the inseparable connections between the uranium migration, enrichment rule and the geochemical characteristics of CO 2 and hydrocarbon gas, as well as the relations between the deposit locations and the gas abnormal distribution in rocky body, which are based on the analysis of some data and phenomena in 11 typical deposits in 2 granite type uranium ore fields, including the observations of 250 rocky fluid inclusion sections and the analyzed data of which 2470 are in gas composition, 200 in uranium content, 50 in thermometry. All the conclusions are drawn from different angles for the first time and this new exploration and advancement fills up the blank of gas geochemistry study in uranium deposits or other metal deposits

  1. Current status and prospects of uranium geology developments of foreign in-situ leachable sandstone type uranium deposits

    International Nuclear Information System (INIS)

    Wang Zhengbang

    2002-01-01

    Firstly, with emphasis on in-situ leachable sandstone-type uranium deposits, the prospecting history of uranium deposits worldwide and its scientific research development are generally reviewed in four steps, and their basic historical experience is also summarized. Secondly, based on the detailed description of current development status of uranium geology of foreign in-situ leachable sandstone-type uranium deposits the important strategic position of sandstone-type uranium deposits in overall uranium resources all-over-the-world and its classification, spatial-temporal distribution and regulation, and metallogenic condition of sandstone-type uranium deposits are analysed thoroughly in five aspects: techtonics, paleo-climate, hydrogeology, sedimentary facies and lithology, as well as uranium sources: Afterwards, evaluation principles of three type of hyper-genic, epigenetic infiltrated sandstone-type uranium deposits are summarized. Based on sandstone-type uranium deposits located two important countries: the United States and Russia, the current development status of prospecting technology for in-situ leachable sandstone-type uranium deposits in foreign countries is outlined. Finally, according to the prospects of supply-demand development of global uranium resources, the author points out seriously that Chinese uranium geology is faced with a severe challenge, and proposes directly four strategic measures that should be taken

  2. Low grade uranium deposits of India - a bane or boon

    International Nuclear Information System (INIS)

    Chaki, Anjan

    2010-01-01

    Uranium resources of the world is estimated to be 5.5 million tonnes and the proven resources in India forms 3% of the world resources. The biggest uranium deposit is the Olympic dam deposit in Australia, which contains nearly one million tonnes of 0.04% U 3 O 8 , while the highest grade of nearly 20% is established in the McArthur river deposit, Canada. Another very high grade deposit, the Cigar lake deposit, is established in Canada with an average grade of nearly 18%. Most of the uranium deposits established in India so far falls under the category of low grade. These low grade uranium deposits are distributed mainly in Singhbhum Shear Zone, eastern India; in parts of Chhattisgarh; Southern parts of Meghalaya; Cuddapah Basin, Andhra Pradesh; in parts of Karnataka and Aravalli- and Delhi Supergroups, Rajasthan and Haryana. These deposits are mainly hydrothermal vein type, stratabound type and unconformity related. The Singhbhum Shear Zone, Jharkhand hosts a seventeen low grade uranium deposits, aggregating about 30% of Indian uranium resources. The uranium mineralisation hosted by Vempalle dolostone extends over 160 km belt along southwestern margin of Cuddapah Basin in Andhra Pradesh and accounts 23% of the Indian resources. Though the dolostone hosted Tummalapalle uranium deposit was established in the early nineties, because of techno-economic constraints, the deposit remained dormant. As a consequence of the development of an innovative pressure alkali beneficiation process, the deposit became economically viable and a mine and mill are being constructed here. Recent exploration inputs are leading to prove a number of low grade uranium deposits in the extension areas of Tummalapalle. Nearly 10 blocks have been identified within a 30 km belt which are being actively explored and a large uranium deposit has already been proved in this province. The deposit at Tummalapalle and adjoining areas is likely to become the second biggest deposit in the world. The

  3. Nature and distribution of surficial deposits in Chryse Planitia and vicinity, Mars

    International Nuclear Information System (INIS)

    Arvidson, R.E.; Guinness, E.A.; Dale-Bannister, M.A.; Adams, J.; Smith, M.; Christensen, P.R.; Singer, R.B.

    1989-01-01

    Color images of bright red dust deposits at the Mutch Memorial Station were acquired at variable incidence angles during sol 611. In blue, green, and red coordinates the vector representing the space radiance factor of the landing site extracted from Viking orbiter images acquired on sol 609 is separated by a Euclidean distance of only 0.022 units and an angle of only 1.5 degree from the vector estimated from the station data for the orbiter lighting and viewing geometries. This result implies that light reflected from dust exposures dominates the orbiter signal; multiplicative and additive atmospheric terms cancel one another and surface roughness is a second-order effect in the orbiter data. Dust radiance factors computed from station data are most like laboratory spectra for fine-grained Hawaiian palagonite and are indistinguishable from Earth-based spectra of classical bright areas. Color composites of orbiter images show that the dust is found immediately south of Acidalia Planitia and in association with topographic barriers such as craters and cliffs. Examination of Viking infrared thermal mapper data shows that the dust deposits typically do not have distinctive thermal inertia signatures, implying that the deposits are optically thick but thinner than the diurnal thermal skin depth. Dark gray material with thermal inertia values indicative of sand grain sizes (0.5-1.5 mm) dominates the Acidalia Planitia lowlands and parts of Kasei Vallis. Space radiance factors of dark gray material are similar to spectra of mafic rock mixed with a minor amount of palagonitelike material

  4. Geological principles of exploration for sandstone-hosted uranium deposits

    International Nuclear Information System (INIS)

    Le Roux, J.P.

    1982-10-01

    Although the importance of sandstone-hosted uranium deposits has seemingly faded in recent years due to the discovery of large, high -grade deposits elsewhere, a forecasted energy shortage in the near future will probably necessitate a new look at sedimentary basins as a source of uranium. Back-arc basins adjacent to calcalkaline source areas are especially favourable if they are filled with fluvial, post-Devonian sediments. Syn- and post-depositional tectonics play an important role in the sedimentation-mineralisation process and should be investigated. The oxidation-reduction state of the sandstones is a valid prospecting tool. Sedimentological environments govern the permeability and vegetal matter content of sandstones and directly control uranium mineralisation

  5. Surficial deposits on salt diapirs (Zagros Mountains and Persian Gulf Platform, Iran): Characterization, evolution, erosion and the influence on landscape morphology

    Czech Academy of Sciences Publication Activity Database

    Bruthans, J.; Filippi, Michal; Asadi, N.; Zare, M.; Šlechta, Stanislav; Churáčková, Z.

    2009-01-01

    Roč. 107, 3-4 (2009), s. 195-209 ISSN 0169-555X R&D Projects: GA AV ČR KJB315040801; GA AV ČR(CZ) KJB301110501 Institutional research plan: CEZ:AV0Z30130516 Keywords : salt diapir * surficial deposit * surface morphology * vegetation cover * erosin rate * Zagros Mountains Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.119, year: 2009

  6. Chemical vapor deposition (CVD) of uranium for alpha spectrometry

    International Nuclear Information System (INIS)

    Ramirez V, M. L.; Rios M, C.; Ramirez O, J.; Davila R, J. I.; Mireles G, F.

    2015-09-01

    The uranium determination through radiometric techniques as alpha spectrometry requires for its proper analysis, preparation methods of the source to analyze and procedures for the deposit of this on a surface or substrate. Given the characteristics of alpha particles (small penetration distance and great loss of energy during their journey or its interaction with the matter), is important to ensure that the prepared sources are thin, to avoid problems of self-absorption. The routine methods used for this are the cathodic electro deposition and the direct evaporation, among others. In this paper the use of technique of chemical vapor deposition (CVD) for the preparation of uranium sources is investigated; because by this, is possible to obtain thin films (much thinner than those resulting from electro deposition or evaporation) on a substrate and comprises reacting a precursor with a gas, which in turn serves as a carrier of the reaction products to achieve deposition. Preliminary results of the chemical vapor deposition of uranium are presented, synthesizing and using as precursor molecule the uranyl acetylacetonate, using oxygen as carrier gas for the deposition reaction on a glass substrate. The uranium films obtained were found suitable for alpha spectrometry. The variables taken into account were the precursor sublimation temperatures and deposition temperature, the reaction time and the type and flow of carrier gas. Of the investigated conditions, two depositions with encouraging results that can serve as reference for further work to improve the technique presented here were selected. Alpha spectra obtained for these depositions and the characterization of the representative samples by scanning electron microscopy and X-ray diffraction are also presented. (Author)

  7. Why jurisdiction and uranium deposit type are essential considerations for exploration and mining of uranium

    International Nuclear Information System (INIS)

    Miller, D.

    2014-01-01

    Uranium is a relatively abundant element, being 25 times more common than silver, and having the same crustal abundance as tin. Economically minable uranium grades vary greatly, from a low of 0.01% U to over 20% U. What are the factors that allow mining of these very low grade ores that are only 50 times background concentrations? Why don’t the high grade deposits of the world exclusively supply all of the worlds newly mined uranium needs? There are two main reasons that the high grade deposits of the world do not exclusively supply all of the worlds newly mined uranium needs: 1) jurisdictional issues, the favorability or lack thereof of governmental policies where the deposit is located and the delays caused by an ineffective or corrupt policy and 2) the deposit type, which has a great influence on the recovery cost of the uranium. The quality of a deposit can override more difficult political jurisdictions if recovery of the investment occurs quickly and in an environmentally friendly way.

  8. Bernabe Montano uranium deposit, Sandoval County

    International Nuclear Information System (INIS)

    Kozusko, R.G.; Saucier, A.E.

    1980-01-01

    Uranium mineralization was discovered on the Bernabe Montano Grant early in 1971. This old land grant, which is part of the Laguna Indian Reservation, is approximately 25 mile northwest of Albuquerque, New Mexico. About 2,000 holes have been drilled on this property to date, and an ore reserve of 10 to 20 million lbs of uranium oxide has been delineated in the Westwater Canyon Member of the Morrison Formation. The mineralization consists of multiple, stacked blankets of mineralized humate which appear to be localized in an area of slightly thicker and more laterally continuous sandstones. The blankets occur along a relatively straight mineral trend about a half mile wide and several miles in length. Holes drilled on-trend usually encounter gamma anomalies, whereas holes drilled off-trend are barren. The uranium is believed to have been carried through the Westwater Canyon Member by ground water that followed the palochannel systems shortly after burial in Late Jurassic time. This discovery once again confirms the trend-ore concept, and it probably represents the present eastern economic limit of the Grants mineral belt. The orebody is unusual because it occurs in a structurally deformed area called the Rio Puerco fault zone. The mineralization, which does not conform to a roll-front model, represents an important addition to the ore reserves of the Grants uranium region

  9. Vein-type and similar uranium deposits of Argentina

    International Nuclear Information System (INIS)

    Stipanicic, P.

    1982-01-01

    Some vein-type and similar uranium deposits and occurrences are briefly described to show different models identified in Argentina. Practically all of them were formerly thought to be related to hydrothermal-magmatic processes, but at present few are considered to be so; some are classified as typically exogenous and opinions differ about the genesis of the remaining ones, especially because of a lack of sufficient research on the matter since this group of accumulations only contributes less than 10% to the entire uranium resources of Argentina. The typical vein-type ore bodies are small (including less than 200t U) with grades varying from 0.1 to near 1%U. Other deposits, resolved as stockworks, could be from small to medium size (more than 200t U to 2000t U) with a uranium content from 0.7 to 0.03%, respectively. The mineralogical associations are variable, from complex ones in veins considered as magmatic-endogenous (with U, Ni, Co, Pb, Cu, Zn, etc.) to very simple ones in the exogenetic accumulations, which only comprise uranium minerals. The paragenetic studies available are not complete enough to define the possible relation of uranium with the other metals in the complex ores. The age of the mineralization has been defined in some cases, but not in others. There are examples of mineralizing processes occurring from Palaeozoic to very recent times. Some of the uranium deposits mentioned here have been exploited in the past; one of them will be re-opened very shortly; and a new one will be put into operation in 1981. The geological composition of Argentina is not favourable for uranium deposits related to the Proterozoic unconformity, and the best possibilities for finding interesting accumulations of vein and similar type are in the large Hercynian granitic environments which have outcrops that cover more than 150,000km 2 (Pampean Hills and North Patagonian Massif). (author)

  10. Method for removing adhering or dust-like deposits in systems handling uranium hexafluoride

    International Nuclear Information System (INIS)

    Bacher, W.; Jacob, E.

    1984-01-01

    A process is claimed for removing adhering or dust-like deposits in an apparatus which handles uranium hexafluoride. The process includes the steps of: (a) reacting the deposits with a gaseous boron halogenide other than boron trifluoride, to form at least one uranium halogenide; and (b) reacting the at least one uranium halogenide with a fluorine containing substance to form uranium hexafluoride

  11. Application potential of sequence stratigraphy to prospecting for sandstone-type uranium deposit in continental depositional basins

    International Nuclear Information System (INIS)

    Li Shengxiang; Chen Zhaobo; Chen Zuyi; Xiang Weidong; Cai Yuqi

    2001-01-01

    Sequence stratigraphy has been widely used in hydrocarbon exploration and development, and great achievements have been achieved. However, its application to the prospecting for sandstone-type uranium deposits is just beginning. The metallogenic characteristics of sandstone-type uranium deposits and those of oil and gas are compared, and the relationship between sandstone-type uranium metallogenesis and the system tracts of sequence stratigraphy is studied. The authors propose that highest and system tracts are the main targets for prospecting interlayer oxidation zone type sandstone uranium deposits, and the incised valleys of low stand system tracts are favourable places for phreatic oxidation zone type sandstone uranium deposits, and transgressive system tracts are generally unfavorable to the formation of in-situ leachable sandstone-type uranium deposits. Finally, the authors look ahead the application potential of sequence stratigraphy to the prospecting for sandstone-type uranium deposits in continental depositional basins

  12. Uranium

    International Nuclear Information System (INIS)

    Mackay, G.A.

    1978-01-01

    The author discusses the contribution made by various energy sources in the production of electricity. Estimates are made of the future nuclear contribution, the future demand for uranium and future sales of Australian uranium. Nuclear power growth in the United States, Japan and Western Europe is discussed. The present status of the six major Australian uranium deposits (Ranger, Jabiluka, Nabarlek, Koongarra, Yeelerrie and Beverley) is given. Australian legislation relevant to the uranium mining industry is also outlined

  13. Uranium deposits in Proterozoic quartz-pebble conglomerates

    International Nuclear Information System (INIS)

    1987-09-01

    This report is the result of an effort to gather together the most important information on uranium deposits in Proterozoic quartz-pebble conglomerates in the United States of America, Canada, Finland, Ghana, South Africa and Australia. The paper discusses the uranium potential (and in some cases also the gold potential in South Africa, Western Australia and Ghana) in terms of ores, sedimentation, mineralization, metamorphism, placers, geologic formations, stratigraphy, petrology, exploration, tectonics and distribution. Geologic history and application of geologic models are also discussed. Glacial outwash and water influx is also mentioned. The uranium deposits in a number of States in the USA are covered. The Witwatersrand placers are discussed in several papers. Refs, figs, tabs

  14. Okelobondo Uranium deposit: Regional context, stratigraphy, sedimentology, tectonic and mineralization

    International Nuclear Information System (INIS)

    Ango, A.M.

    1993-01-01

    This paper describes briefly the geology of Okelobondo uranium deposit (Gabon) and gives the study prospects of natural reactor phenomenon which depends of the operating progress state. Oklo phenomenon is considered as the best natural analogue for the study of radionuclide migration. 3 figs

  15. Behavior of uranium migration in epigenetic uranium ore deposits with reference to radioactive waste isolation in geologic media

    International Nuclear Information System (INIS)

    Doi, K.; Hirono, S.

    1989-01-01

    Among the numerous uranium ore deposits and indications which have been discovered in Japan, the important uranium occurrences are found as strata-bound epigenetic ore deposits. This mineralization occurs in basal Neogene sedimentary rocks unconformably overlying granitic basements of the Mesozoic and/or early Cenozoic era. In many of these deposits, the epigenetic uranium mineralization occurs just above the unconformity, and groundwater migration is observed at the unconformity between the Neogene sediments and the granitic basement. This groundwater at the unconformity is thought to be a migrating agent for uranium from source rock to the ore deposit

  16. Physical properties and radiometric age estimates of surficial and fracture-fill deposits along a portion of the Carpetbag fault system, Nevada Test Site, Nye County, Nevada

    International Nuclear Information System (INIS)

    Shroba, R.R.; Muhs, D.R.; Rosholt, J.N.

    1988-07-01

    Surficial deposits and fracture-fill deposits (fracture fillings that consist chiefly of calcium carbonate-cemented, pebbly sand) were studied along a 2.5-km-long portion of the Carpetbag fault system in an area characterized by prominent, explosion-produced scarps and a shallow graben that formed during and subsequent to the 1970 Carpetbag nuclear event in the northwestern part of Yucca Flat, Nevada Test Site. The surficial deposits are fluvial and slopewash deposits and mixed eolian sediment that range in grain size from pebble gravel to silty sand. These deposits have been modified by the accumulation of varying amounts of pedogenic silt, clay, calcium carbonate, and probably opaline silica. Despite the occurrence of ancient fractures and linear features on aerial photographs, that are near and parallel to subsurface faults of the Carpetbag system, no other evidence for prehistoric surface faulting was observed in the study area. The lack of prehistoric fault scarps and the lack of offset of stratigraphic contacts exposed in trench excavations suggest that no significant vertical surface displacement has occurred on the Carpetbag system during the past 125,000 years and possible during the past 350,000 years. 39 refs., 12 figs., 8 tabs

  17. Discussion on the interlayer oxidation and uranium metallogenesis in Qianjiadian uranium deposit, Songliao Basin

    International Nuclear Information System (INIS)

    Pang Yaqing; Chen Xiaolin; Fang Xiheng; Sun Ye

    2010-01-01

    Through systematic drill core observation, section contrast and analysis,it is proved that the ore-controlling interlayer oxidation zone of Qianjiadian uranium deposit is mainly composed by the red oxidized sandstone and locally distributed yellow and off-white sandstones. The red sandstone contains charcoal fragments, pyrite, ilmenite, siderite, which have been oxidized intensively, and it can be deduced that their original color was gray and became red due to the oxidization. The distribution of the oxidation zone is mainly controlled by the sedimentary facies,which also controll uranium metallization. The uranium orebodies mainly developed in the thinning or pinch parts of the red oxidation zone in section. On the plans, the uranium mineralization distributes near the front of the red interlayer oxidation zone. (authors)

  18. Uraninite in the uranium deposits of Singhbhum Shear Zone, Bihar

    International Nuclear Information System (INIS)

    Krishna Rao, N.; Rao, G.V.U.

    1980-01-01

    Uraninite is the main uranium mineral in the uranium deposits of Singhbhum Shear Zone, Bihar. The uraninite from different deposits have compositions varying between UOsub(2.30) to UOsub(2.44) which is typical of vein uraninites. They contain 2 , but have appreciable rare earths (approximately equal to 5%). They also contain 12-15% PbO, which is all radiogenic. Among the rare earths the heavy lanthanides predominate. In addition uraninite from Narwapahar shows an enrichment in Eu. The unit cell edge of uraninite from different deposits varies between 5.420 A and 5.453 A. The uraninite from the copper deposits of Rakha and Surda, and Narwapahar have decidedly higher cell edge (5.45 A) than those from Bhatin and Jaduguda (5.42 A). On annealing at 1000deg C in an inert atmosphere the cell edge decreased to a near constant value of 5.428 A, the contraction varying between 0.01 A to 0.03 A. D.T.A. and T.G.A. curves of Narwapahar and Bhatin uraninite indicate that these differ considerably from those of pure UO 2 . There are also significant differences between the two. These differences are attributed to crystallinity and degree of disorder in the uraninite lattice. The variations in the composition, cell edge, annealing and oxidation characteristics of uraninite from different uranium deposits reflect different temperature conditions during their formation. (author)

  19. Pena Blanca uranium deposits and ash-flow tuffs relationship

    International Nuclear Information System (INIS)

    Magonthier, M.

    1987-01-01

    The Pena Blanca uranium deposits (Chihuahua, Mexico) are associated with a Tertiary sequence of ash-flow tuffs. Stratigraphic control is dominant and uranium mineralization occurs in stratiform and fracture-controlled deposits within 44 My-old units: Nopal Rhyolite and Escuadra Rhyolite. These units consist of highly vapor-phase crystallized ash-flow tuffs. They contain sanidine, quartz and granophyric phenocrysts, and minor ferromagnesian silicates. Nopal and Escuadra units are high-silica alkali-rich rhyolites that have a primary potassic character. The trace-element chemistry shows high concentrations in U-Th-Rb-Cs and low contents in Ba-Sr-Eu. These chemical properties imply a genetic relationship between deposits and host-units. The petrochemical study show that the Nopal Rhyolite and Escuadra Rhyolite are the source of U and of hydrothermal solutions [fr

  20. Optimization of Uranium Molecular Deposition for Alpha-Counting Sources

    Energy Technology Data Exchange (ETDEWEB)

    Monzo, Ellen [Univ. of Minnesota, Duluth, MN (United States); Parsons-Moss, Tashi [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Genetti, Victoria [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Knight, Kimberly [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-12-12

    Method development for molecular deposition of uranium onto aluminum 1100 plates was conducted with custom plating cells at Lawrence Livermore National Laboratory. The method development focused primarily on variation of electrode type, which was expected to directly influence plated sample homogeneity. Solid disc platinum and mesh platinum anodes were compared and data revealed that solid disc platinum anodes produced more homogenous uranium oxide films. However, the activity distribution also depended on the orientation of the platinum electrode relative to the aluminum cathode, starting current, and material composition of the plating cell. Experiments demonstrated these variables were difficult to control under the conditions available. Variation of plating parameters among a series of ten deposited plates yielded variations up to 30% in deposition efficiency. Teflon particles were observed on samples plated in Teflon cells, which poses a problem for alpha activity measurements of the plates. Preliminary electropolishing and chemical polishing studies were also conducted on the aluminum 1100 cathode plates.

  1. The Blind River uranium deposits: the ores and their setting

    International Nuclear Information System (INIS)

    Robertson, J.A.

    1976-01-01

    The Matinenda Formation (basal Huronian) comprises northward-derived arkose, quartzite, and pyritic, uraniferous oligomictic conglomerate that contains 75 percent of Canada's uranium reserves. The conglomerate beds occur in southeasterly striking zones controlled by basement topography down-sedimentation from radioactive Archean granite. The mineralization is syngenetic, probably placer. Drab-coloured rocks, uranium and sulphide mineralization, and a post-Archean regolith formed under reducing conditions, suggest a reducing environment. Sedimentary features indicate deposition in fast-flowing shallow water, and possibly a cold climate. (author)

  2. Hydrothermal convection and uranium deposits in abnormally radioactive plutons

    International Nuclear Information System (INIS)

    1978-09-01

    Hydrothermal uranium deposits are often closely associated with granites of abnormally high uranium content. We have studied the question whether the heat generated within such granites can cause fluid convection of sufficient magnitude to develop hydrothermal uranium deposits. Numerical models of flow through porous media were used to calculate temperatures and fluid flow in and around plutons similar to the Conway Granite, New Hampshire, i.e. with a halfwidth of 17 km, a thickness of 6.25 km, and with a uniform internal heat generation rate of 20 x 10 -13 cal/cm 3 -sec. Fluid convection was computed for plutons with permeabilities between 0.01 and 5 millidarcies (1 x10 -13 cm 2 to 5 x 10 -11 cm 2 . Flow rates and the size and location of convection cells in and around radioactive plutons like the Conway Granite were found to depend critically on the permeability distribution within the pluton and in adjacent country rocks. The depth of burial, the distribution of heat sources within the pluton, and small rates of heat generation in the country rock are only of minor importance. Topographic relief is unlikely to effect flow rates significantly, but can have a major influence on the distribution of recharge and discharge areas. Within a few million years, the mass of water transported by steady state convection through such radioactive plutons can equal the mass of water which can convect through them during initial cooling from magmatic temperatures. If the permeability in a Conway-type pluton is on the order of 0.5 millidarcies, the rate of fluid convection is probably sufficient to develop a hydrothermal ore deposit containing 10,000 tons of uranium in a period of two million years. Such a uranium deposit is most likely to develop in an area of strong upwelling or strong downwelling flow

  3. Exploration on relationship between uranium and organic materials in carbonate-siliceous pelite type uranium ore deposits

    International Nuclear Information System (INIS)

    Dong Yongjie

    1996-01-01

    The author determines the content of uranium and organic carbon of part specimen of surrounding rocks and ores, which sampled from carbonate and black shale type uranium deposits in Xiushui, Jiangxi Province, and Tongcheng, Hubei Province. According to the analytical operation regulations of organic materials, extraction and separation of chloroform pitch is carried out. Internal relationships between uranium and organic derivative is discussed. The conclusion shows that: (1) certain co-relationship between U and organic carbon and chloroform extract is detected; (2) evolutionary processes of organic materials in the exogenetic uranium deposits are not all the same; (3) non-hydrocarbon is closely related to uranium, so it can be regarded as indicator of uranium gathering in exogenetic uranium deposits

  4. Uranium-series dating of Quaternary deposits

    International Nuclear Information System (INIS)

    Schwarcz, H.; Gascoyne, M.

    1984-01-01

    In view of the interest in the problem of time scales in geomorphology it is fortunate that there exists a number of geochronometers applicable to the measurement of the age of such young deposits. This paper is specifically devoted to those which arise from the disequilibrium between the daughter isotopes of U-238 and U-235, and their respective parents. The authors describe applications to Quaternary continental deposits that can give information about climatic change (travertine, lacrustine limestones, pedogenic carbonates, detrinal sediments, volcanic rocks). (Auth.)

  5. Application of base-level cycles to sandstone-type uranium deposit: taking Dongsheng uranium deposits as an example

    International Nuclear Information System (INIS)

    Yang Renchao; Han Zuozhen; Fan Aiping; Chang Xiangchun

    2006-01-01

    High-resolution sequence stratigraphy taking base-level cycles as interface of reference was developed rapidly in recent years. Its greatest predominance lies in that it can be applied to multi-controled continental sedimentary basins and can effectively improve accuracy and distinguishability of sequence stratigraphy analysis. Principles of base-level cycles can also be applied to the research and practice of the exploration and exploitation of sandstone-type uranium deposits as they control the spatial distribution, porosity, the permeability and the sealing ability of sandstone and mudstone, and stacking patterns of strata configuration. Taking Dongsheng uranium deposits as an example, the application of base-level cycles to exploration and exploitation of sandstone uranium deposits was analyzed. It is suggested that favorable strata framework of sandstone and mudstone was developed very well in the fluctuation of base-level cycles. Sand bodies were provided with good connectedness, coarse granularity, high debris content, low matrix content and good porosity-permeability becoming the most important uranium hosted strata. (authors)

  6. Geological and geochemical aspects of uranium deposits. A selected, annotated bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Garland, P.A.; Thomas, J.M.; Brock, M.L.; Daniel, E.W. (comps.)

    1980-06-01

    A bibliography of 479 references encompassing the fields of uranium and thorium geochemistry and mineralogy, geology of uranium deposits, uranium mining, and uranium exploration techniques has been compiled by the Ecological Sciences Information Center of Oak Ridge National Laboratory. The bibliography was produced for the National Uranium Resource Evaluation Program, which is funded by the Grand Junction Office of the Department of Energy. The references contained in the bibliography have been divided into the following eight subject categories: (1) geology of deposits, (2) geochemistry, (3) genesis O deposits, (4) exploration, (5) mineralogy, (6) uranium industry, (7) reserves and resources, and (8) geology of potential uranium-bearing areas. All categories specifically refer to uranium and thorium; the last category contains basic geologic information concerning areas which the Grand Junction Office feels are particularly favorable for uranium deposition. The references are indexed by author, geographic location, quadrangle name, geoformational feature, taxonomic name, and keyword.

  7. Geological and geochemical aspects of uranium deposits. A selected, annotated bibliography

    International Nuclear Information System (INIS)

    Garland, P.A.; Thomas, J.M.; Brock, M.L.; Daniel, E.W.

    1980-06-01

    A bibliography of 479 references encompassing the fields of uranium and thorium geochemistry and mineralogy, geology of uranium deposits, uranium mining, and uranium exploration techniques has been compiled by the Ecological Sciences Information Center of Oak Ridge National Laboratory. The bibliography was produced for the National Uranium Resource Evaluation Program, which is funded by the Grand Junction Office of the Department of Energy. The references contained in the bibliography have been divided into the following eight subject categories: (1) geology of deposits, (2) geochemistry, (3) genesis O deposits, (4) exploration, (5) mineralogy, (6) uranium industry, (7) reserves and resources, and (8) geology of potential uranium-bearing areas. All categories specifically refer to uranium and thorium; the last category contains basic geologic information concerning areas which the Grand Junction Office feels are particularly favorable for uranium deposition. The references are indexed by author, geographic location, quadrangle name, geoformational feature, taxonomic name, and keyword

  8. Hydrothermal uranium vein deposits in Marysvale volcanic field, Utah

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, J.D.; Cunningham, C.G.; Steven, T.A.; Rye, R.O.; Romberger, S.B.

    1984-07-01

    Hydrothermal uranium veins are exposed over a 300 m (980 ft) vertical range in mines of the Central Mining area, near Marysvale, Utah. They cut 23 Ma quartz monzonite, 21 Ma granite, and 19 Ma rhyolite ash-flow tuff. The veins formed 18-19 Ma, in an area 1 km (0.6 mi) across, above the center of a composite magma chamber at least 12 x 6 km across that fed a sequence of 21-14 Ma hypabyssal granitic stocks, and rhyolitic lava flows, ash-flow tuffs, and volcanic domes. Intrusive pressure uplifted and fractured the roof; molybdenite-bearing, uranium-rich glassy dikes were intruded; and a breccia pipe and uranium-bearing veins were formed. The veins appear to have been deposited near the surface above a concealed rhyolite stock, where they filled high-angle fault zones and flat-lying to concave-downward pull-apart fractures. Low pH and fO/sub 2/ hydrothermal fluids at temperatures near 200/sup 0/ C (392/sup 0/ F) permeated the fractured rocks; these fluids were rich in fluorine and potassium, and contained uranium as uranous-fluoride complexes. Fluid-wall rock interaction increased fluid pH, causing precipitation of uranium minerals. At the deepest exposed levels, wall rocks were altered to kaolinite and sericite, and uraninite, coffinite, jordisite, fluorite, molybdenite, quartz, and pyrite (with delta/sup 34/S near zero per mil) were deposited. The fluids were progressively oxidized higher in the system; iron in the wall rocks was oxidized to hematite, and sooty uraninite and umohoite were deposited.

  9. Proterozoic strata-bound uranium deposits of Zambia and Zaire

    International Nuclear Information System (INIS)

    Meneghel, L.

    1984-01-01

    The Katanga System, host to uranium and copper mineralisation, is several thousands of metres thick and rests unconformably on an older complex of crystalline rocks and metasediments and is locally covered by Karoo sandstones or Kalahari sands. The deposition of the Katanga System took place during the Late Proterozoic in a wide complex basin extending from Shaba province in Zaire through a large part of Zambia and into eastern Angola. The sediments were affected by different grades of metamorphism, tectonic events, and by thermal events associated with post-tectonic metamorphism. At the base of Katanga system there are 84 known copper deposits and 42 uranium occurrences. It is suggested that all the known uranium and copper occurrences are of an essentially syngenetic sedimentary origin. The mineralisation is found in the Lower Roan Formation near the base of the Katanga System occurring in rocks produced in similar environmental conditions and thus being stratigraphic controlled, however, their areal distribution is localised producing a regional metal zonation. Many of the uranium occurrences have a typical vein aspect. These transgressive relationships are not inconsistent with a syngenetic origin as evidenced by the vein morphology. (author)

  10. Uranium deposits in the Nord-Limousin

    International Nuclear Information System (INIS)

    Sarcia, J.A.; Sarcia, J.A.

    1958-01-01

    The authors briefly consider the region in its geographical and geological setting. They describe the main petrographic, metallogenic and tectonic characteristics of the sector investigated by the Atomic Energy Commission since 1947, stressing the form of uraniferous mineral deposits. This short account is intended as a general presentation of the detailed studies which will follow, of which that dealing with the mine Henriette is the first to be published. (author) [fr

  11. Criticality safety aspects of K-25 Building uranium deposit removal

    International Nuclear Information System (INIS)

    Haire, M.J.; Jordan, W.C.; Ingram, J.C. III; Stinnet, E.C. Jr.

    1995-01-01

    The K-25 Building of the Oak Ridge Gaseous Diffusion Plant (now the K-25 Site) went into operation during World War II as the first large scale production plant to separate 235 U from uranium by the gaseous diffusion process. It operated successfully until 1964, when it was placed in a stand-by mode. The Department of Energy has initiated a decontamination and decommissioning program. The primary objective of the Deposit Removal (DR) Project is to improve the nuclear criticality safety of the K-25 Building by removing enriched uranium deposits from unfavorable-geometry process equipment to below minimum critical mass. The method utilized to accomplish this are detailed in this report

  12. Paragenesis and Geochronology of the Nopal I Uranium Deposit, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    M. Fayek; M. Ren

    2007-02-14

    Uranium deposits can, by analogy, provide important information on the long-term performance of radioactive waste forms and radioactive waste repositories. Their complex mineralogy and variable elemental and isotopic compositions can provide important information, provided that analyses are obtained on the scale of several micrometers. Here, we present a structural model of the Nopal I deposit as well as petrography at the nanoscale coupled with preliminary U-Th-Pb ages and O isotopic compositions of uranium-rich minerals obtained by Secondary Ion Mass Spectrometry (SIMS). This multi-technique approach promises to provide ''natural system'' data on the corrosion rate of uraninite, the natural analogue of spent nuclear fuel.

  13. Prerequisites for the formation of large hydrothermal and exogenic-epigenetic uranium deposits

    International Nuclear Information System (INIS)

    Mashkovets, G.A.; Kislyakov, Ya.M.; Miguta, A.K.; MOdnikov, I.S.; Shchetochkin, V.N.

    1995-01-01

    Data on ore reserves and quality of the most important uranium ore regions of the world are analyzed. Large-size hydrothermal and exogenic-epigenetic (hydrogenic) uranium deposits are considered to be the basic uranium producers. The most general prerequisits for large ore objects formation and determined by example of leading industrial-genetic types of ore deposits of both groups

  14. Olympic Dam copper-uranium-gold deposit, South Australia

    International Nuclear Information System (INIS)

    Lalor, J.H.

    1986-01-01

    The Olympic Dam copper-uranium-gold deposit was discovered in July 1975. It is located 650 km north-northwest of Adelaide on Roxby Downs Station in South Australia. The first diamond drill hole, RD1, intersected 38 m of 1.05% copper. A further eight holes were drilled with only marginal encouragement to November 1976, when RD10 cored 170 m of 2.12% copper and 0.06% of uranium oxide, thus confirming an economic discovery. The discovery of Olympic Dam is an excellent example applying broad-scale, scientifically based conceptual studies to area selection. Exploration management supported its exploration scientists in testing their ideas with stratigraphic drilling. Geologic modeling, supported by geophysical interpretations and tectonic studies, was used to site the first hole. The discovery also illustrates the persistence required in mineral exploration. The deposit appears to be a new type of stratabound sediment-hosted ore. It has an areal extent exceeding 20 km 2 with vertical thicknesses of mineralization up to 350 m. It is estimated to contain more than 2000 million MT of mineralized material with an average grade of 1.6% copper, 0.06% uranium oxide, and 0.6 g/MT gold. The deposit occurs in middle Proterozoic basement beneath 350 m of unmineralized, flat upper Proterozoic sediments. The sediments comprising the local basement sequence are predominantly sedimentary breccias controlled by a northwest-trending graben

  15. URANIUM-SERIES CONSTRAINTS ON RADIONUCLIDE TRANSPORT AND GROUNDWATER FLOW AT NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    S. J. Goldstein, S. Luo, T. L. Ku, and M. T. Murrell

    2006-04-01

    Uranium-series data for groundwater samples from the vicinity of the Nopal I uranium ore deposit are used to place constraints on radionuclide transport and hydrologic processes at this site, and also, by analogy, at Yucca Mountain. Decreasing uranium concentrations for wells drilled in 2003 suggest that groundwater flow rates are low (< 10 m/yr). Field tests, well productivity, and uranium isotopic constraints also suggest that groundwater flow and mixing is limited at this site. The uranium isotopic systematics for water collected in the mine adit are consistent with longer rock-water interaction times and higher uranium dissolution rates at the front of the adit where the deposit is located. Short-lived nuclide data for groundwater wells are used to calculate retardation factors that are on the order of 1,000 for radium and 10,000 to 10,000,000 for lead and polonium. Radium has enhanced mobility in adit water and fractures near the deposit.

  16. Use of Rutherford Backscattering to determine uranium deposit uniformity

    International Nuclear Information System (INIS)

    Wasson, O.A.; Schrack, R.A.

    1988-01-01

    A Rutherford Backscattering (RBS) facility has been established at the 3-MV positive-ion accelerator at the National Bureau of Standards. This facility has been used to study the areal density distribution of uranium deposits used in neutron cross section measurements. A versatile scattering chamber with numerous ports, five-axis goniometer, target ladder, and solid state detector is in operation. Beams of 1 MeV He + ions and 5 MeV He ++ ions are available. The variation in areal density of a 75 cm diameter UO 2 deposit was measured using a 1 MeV He + beam. The results are in excellent agreement with those obtained from alpha-particle activity measurements. However, the RBS measurements provide better definition of the uniformity near the edge of the deposits. Our experience in the use of these two methods to characterize the areal densities of deposits for cross section measurements will be presented. (author). Abstract only

  17. Formation conditions for regenerated uranium blacks in uranium-molybdenum deposits

    International Nuclear Information System (INIS)

    Skvortsova, K.V.; Sychev, I.V.; Modnikov, I.S.; Zhil'tsova, I.G.

    1980-01-01

    Formation conditions of regenerated uranium blacks in the zone of incomplete oxidation and cementation of uranium-molybdenum deposit have been studied. Mixed and regenerated blacks were differed from residual ones by the method of determining excess quantity of lead isotope (Pb 206 ) in ores. Determined were the most favourable conditions for formation of regenerated uranium blacks: sheets of brittle and permeable volcanic rocks characterized by heterogeneous structure of a section, by considerable development of gentle interlayer strippings and zones of hydrothermal alteration; predominance of reduction conditions in a media over oxidation ones under limited oxygen access and other oxidating agents; the composition of hypogenic ores characterized by optimum correlations of uranium minerals, sulfides and carbonates affecting violations of pH in oxidating solutions in the range of 5-6; the initial composition of ground water resulting from climatic conditions of the region and the composition of ore-bearing strata and others. Conditions unfavourable for the formation of regenerated uranium blacks are shown

  18. Study on geochronology and uranium source of sandstone-type uranium deposit in Dongsheng area

    International Nuclear Information System (INIS)

    Liu Haibin; Xia Yuliang; Tian Shifeng

    2007-01-01

    This paper studied the geochronology of sandstone-type uranium deposit in the Dongsheng area of Ordos Basin. In eastern segment, ages of mineralization at the wing of the ore-roll are found to be 120 ± 5 Ma and 80 ± 5 Ma, and at the front of the ore-roll are 20 ± 2 Ma and 8 ± 1 Ma; While in middle segment, ages of mineralization are 124 ± 6 Ma and 80 ± 5 Ma. This means that the main mineralization in Dongsheng area were formed at early Jurassic and late Cretaceous, and correspondent to the time of structure uplift. Mineralization of roll-front (rich ore) which formed in Miocene and Pliocene may related to tectonic-thermal event taken place at that time and reformed the early mineralization in this area. The isochron line age of sample with uranium grade 0 ) in the sandbody is 24.64 x 10 -6 also shows the uranium pre-concentration in the strata. The even value of ΔU of rocks in Zhiluo formation is -70.2%, this shows that non-mineralized rocks have migrated uranium and acted as important metallogenic uranium sources. (authors)

  19. Uranium deposits of Gabon and Oklo reactors. Metallogenic model for rich deposits of the lower proterozoic

    International Nuclear Information System (INIS)

    Gauthier-Lafaye, F.

    1986-05-01

    The geology of the Franceville basin (Gabon) is examined: stratigraphy, tectonics and geodynamics. The mobile zone of the Ogooue is specially studied: lithology, metamorphism and tectonics, isotopic geochronologic data are given. The different uranium deposits are described. A whole chapter is devoted to the study of Oklo natural nuclear reactor. A metallogenic model is proposed evidencing conditions required for deposit genesis. Tectonics, microstructures sedimentology, organic matter, diagenesis and uraniferous mineralizations are examined [fr

  20. Clay minerals in sandstone uranium deposits: radwaste applications

    International Nuclear Information System (INIS)

    Brookins, D.G.

    1990-01-01

    Clay minerals play an important role in the genesis of uranium deposits in sandstones. They incorporate the rate earths (REE), U, Sb, Th, Cs, Rb, Sr, Y, Ba, and even small amounts of chalcophiles. These minerals possess analog elements for many of the radwaste fission products as well as actinides and some actinide daughters. In sandstone uranium deposits, clay minerals are also associated with sulfide minerals, usually pyrite, and organic carbonaceous matter. The primary clay minerals are usually smectites, illites, chlorites and mixed layer varieties. The integrity of these clay minerals is demonstrated by their retention of formational-mineralization ages determined by Rb-Sr geochronologic investigation of the Grants Mineral Belt of the United States. The importance of the clay minerals as analog for parts of the multi-barrier concept in radwaste disposal is their ability to impede water penetration into - and movement of key elements out of uranium rich zones. The clay minerals further sorb and in other ways incorporate into their structures many fission products and actinide analogs from man-made nuclear wastes. 22 refs., 1 fig., 3 tabs

  1. Study of the Formation of Eutectic Melt of Uranium and Thermal Analysis for the Salt Distillation of Uranium Deposits

    International Nuclear Information System (INIS)

    Park, Sung Bin; Hwang, Sung Chan; Kang, Young Ho; Park, Ki Min; Jun, Wan Gi; Lee, Han Soo; Cho, Dong Wook

    2010-01-01

    Uranium deposits from an electrorefining process contain about 30% salt. In order to recover pure uranium and transform it into an ingot, the salts have to be removed from the uranium deposits. Major process variables for the salt distillation process of the uranium deposits are hold temperature and vacuum pressure. Effects of the variables on the salt removal efficiency were studied in the previous study 1. By applying the Hertz-Langmuir relation to the salt evaporation of the uranium deposits, the evaporation coefficients were obtained at the various conditions. The operational conditions for achieving above 99% salt removal were deduced. The salt distilled uranium deposits tend to form the eutectic melt with iron, nickel, chromium for structural material of salt evaporator. In this study, we investigated the hold temperature limitation in order to prevent the formation of the eutectic melt between uranium and other metals. The reactions between the uranium metal and stainless steel were tested at various conditions. And for enhancing the evaporation rate of the salt and the efficient recovery of the distilled salt, the thermal analysis of the salt distiller was conducted by using commercial CFX software. From the thermal analysis, the effect of Ar gas flow on the evaporation of the salt was studied.

  2. Wallrock hydronica metasomatites associated with uranium deposits in folded regions

    International Nuclear Information System (INIS)

    Velichkin, V.I.; Volovikova, I.M.

    1980-01-01

    Hydrothermal uranium deposits of one of the Paleozoic folded regions have been studied. A new type of hydromica metasomatites has been found, the mineral composition of which depends on enclosing rocks: in silicic formations the metasomatites of quartz hydromica facies are developed, in the rocks of the base composition those of carbonate-hydromica facies. Locally developed are chlorite-hydromica metasomatites. Hydromica metasomatites and related to them veined uranium mineralization are characterized by a stable positional connection with large intrusives of postfolded low-deep granites and are coincided to exocontact aureoles of granite cupolas. Hydromicatizer formation took place under low temperature and pressure conditions. The conclusion on a probable formation independence of hydromica metasomatites is made [ru

  3. Nondestructive uranium enrichment determination in process holdup deposits

    International Nuclear Information System (INIS)

    Hagenauer, R.C.

    1992-01-01

    A new technique has been developed for analyzing the gamma-ray spectra of uranium compounds to determine the relative abundance of all gamma-ray emitting isotopes present. The technique works well for samples whose gamma-ray absorption properties are not well defined and has become an invaluable tool for characterizing inventory samples and residual uranium held up in process equipment. The gamma rays in a spectrum obtained with a hyperpure germanium detector are corrected for container attenuation, sample self absorption, and branching ratios. The gamma rays within a spectrum can be used to compute the container attenuation and the sample self absorption. Gamma rays emitted from deposits of uranium within a container are subject to two different absorption correction factors, container attenuation and sample self-absorption. Because of the uranium K edge effects, an X ray at 89.96 keV and a gamma ray at 143.7 keV, emitted from 235 U decay, have similar mass-attenuation properties. After correcting for the gamma-ray branching ratios, the sample self absorption correction factors for these two radiations can be held constant while the container attenuation is computed. Container thicknesses are estimated in an iterative manner until the corrected peak areas of these two radiations are the same. Once the container thickness and its corresponding correction factors are computed, then the sample self absorption correction factors can be computed using all the gamma rays in a spectrum for each particular isotope. After correcting for branching ratios, sample thicknesses are estimated and correction factors computed in an iterative manner until all the gamma and X ray peaks areas are the same for each isotope. When all the corrections are properly computed then atomic abundances are proportional to the corrected peak areas for each isotope. The technique works well on a variety of deposits

  4. The copper and uranium deposits of the Coyote district, Mora County, New Mexico

    Science.gov (United States)

    Tschanz, C.M.; Laub, D.C.; Fuller, G.W.

    1954-01-01

    The copper and uranium-vanadium deposits of the Coyote district, Mora County, N. Mec, are confined to the lower 2,000 feet of the Sangre de Gristo formation of Pennsylvanian and Permian age. A narrow belt of deposits in steeply dipping or overturned rocks extends for 7 miles along Coyote Creek south of Guadalupita. Earlier studies showed that the copper deposits contained uranium, but both the reserves and the uranium content of the copper-bearing

  5. Further new activities at uranium deposit Rozna, Czech Republic

    International Nuclear Information System (INIS)

    Toman, F.; Pavel, V.

    2014-01-01

    Mining of uranium ore has been running at Rozna deposit for 56 years, since 1957. Extraction of uranium ore is currently performed in the mining field of blind shaft R7S. Top slicing and caving under the artificial roof method is used for the extraction. Uranium ore mined in the Rozna deposit is treated at a chemical treatment plant (a mill) situated in the close vicinity of the Rozna mine. In the mill, uranium is extracted from the crushed and ground ore by alkaline leaching. The uranium is then removed from the solution by sorption on resin; the next steps are precipitation and drying. Alkaline leaching is applied at the atmospheric pressure and the temperature of 80 °C. The final product of the milling is ammonium diuranate (NH 4 ) 2 U 2 O 7 , which is further treated into a fuel for nuclear power plants in conversion facilities abroad. The milling is carried on under the condition of the closed cycle of technology water. Due to the positive annual precipitation balance, the over balance of mill water in tailings pond has to be purified before discharging into a river. Forced evaporation and membrane processes (electrodialysis and reverse osmosis) are used to purify the water. New activities are searched and carried out with consequence of gradual decreasing of the uranium production. The main target and also benefit of this is the using of skilled human resources in the mine Rozna I and entry able underground spaces. Geological exploration works for a construction of the underground gas storage were started on 21st level of shaft R7S three years ago. New horizontal galleries with profile 9 m 2 were driven during geological exploration works. Exploratory holes with length 100m were drilled. Sampling of rocks for geochemical, geomechanical and petrographic tests were carried out. So far 1264.9 m of exploration galleries and 1130 m exploration drill holes have been made. Geological exploration works for construction of underground research workplace on 12th level

  6. Towards a genetic classification of uranium deposits; Vers une classification genetique des gisements d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Cuney, M. [G2R, Nancy Universite, CNRS, CREGU, 54 - Vandoeuvre les Nancy (France)

    2009-07-01

    As the IAEA's uranium deposit classification is based on the deposit nature and morphology, some deposits which have been formed by very different genetic processes and located in very different geological environments, are grouped according to this classification. In order to build up a reliable genetic classification based on the mechanism at the origin of the formation of the deposit, the author presents the five main categories according to which uranium deposits can be classified: magmatic, hydrothermal, evapotranspiration, syn-sedimentary, and infiltration of meteoric water

  7. Evolution of ore-bearing material sources of endogenous uranium deposits

    International Nuclear Information System (INIS)

    Kazansk, V.I.; Laverov, N.P.; Tugarinov, A.I.

    1976-01-01

    Considered are the regularities of changes in types and conditions of uranium deposit formation in connection with the general development of the earth crust tectonic structures. Out of pre-Kembrian uranium deposits considered are Vitwatersrand conglomerates, hydrothermal deposits in pre-Kembrian iron quartzites in the areas of regional fractures in exocontacts of big multiphase granitoid massifs of Proterozoic age and in the fundament folded structures. The hydrothermal-metamorphogen theory is supported of the origin of uranium-bearing sodium metasomatite of Proterozoic, including uranium deposits in the area of the Atabaska lake. Four genetic classes of Palaeozoic deposits are considered. Four periods are singled out in the development of Palaeozoic uranium provinces. Most of the Palaeozoic deposits are shown to be of polygenous origin. Mesozoic deposits are also polygenous, but the combination of ore substance sources in them is more complex

  8. Blind River uranium deposits: the ores and their setting

    International Nuclear Information System (INIS)

    Robertson, J.A.

    1981-01-01

    In the Blind River area, Proterozoic clastic sedimentary and minor volcanic rocks (Huronian Supergroup) unconformably overlie and transgress northward over dominantly granitic Archean terrane (2500 million years) and are intruded by Nipissing Diabase (2150 million years). Later deformations and metamorphic events are recognized. The Matinenda Formation (basal Huronian) comprises northward-derived arkose, quartzite, and pyritic, uraniferous oligomictic conglomerates, which contain 75 percent of Canada's uranium reserves. Historic grades approximate 2 pounds U 3 O 8 /ton (1 kilogram/metric ton), but lower grade material can be mined with increasing price. Some thorium and rare earths have been marketed. The conglomerate beds lie in southeasterly striking zones controlled by basement topography down-sedimentation from radioactive Archean granite. Distribution of monazite relative to uraninite and brannerite and the presence of uranium values in overlying polymictic conglomerates, which truncate the ore beds, indicate that the mineralization is syngenetic, probably placer. The role of penecontemporaneous mafic volcanics is problematical, but these could have been a source for sulphur in the pyrite. Drab-coloured rocks, uranium and sulphide mineralization, and a post-Archean regolith formed under reducing conditions all suggest a reducing environment. Sedimentary features indicate deposition in fast-flowing shallow water and possibly a cold climate. In the upper Huronian (Lorrain Formation), a monazite and iron oxide assemblage associated with red beds suggests a change to oxidizing conditions

  9. Contribution to the methods for estimating uranium deposits (1963)

    International Nuclear Information System (INIS)

    Carlier, A.

    1964-02-01

    Having defined a deposit of economic value according to the marginal theory, the author discriminates several categories of ore reserves according to the degree of knowledge of the deposit and according to the mining stage where the ore is considered. He dismisses the conventional French classification of 'on sight', 'probable' and 'possible' ore categories and suggests more suitable ones. The 'sensu stricto', ore reserves are those for which the random error can be calculated. The notion of the natural contrast of grades in an ore deposit (absolute dispersion coefficient α) is introduced in relation to this topic. The author considers three types of mining exploration. The first is the random exploration so often met; the second is the logical exploration based on a systematic location of underground works, bore-holes, etc. The third, and hardest to achieve, is the one which minimizes exploration costs for a given level of accuracy. Part of the publication deals with sampling errors such as those resulting from the quartering of a heap of ore (theory of Pierre GY) or those resulting from the use of radiometric measurement of grade. Another part deals with the extension error (entailed by the assimilation of samples to the deposit they are issued from) and gives the essential formulae in order to appraise the random error (Geo-statistics of Matheron). As to the estimator itself the work shows how the disharmony between the ore sample and the associated influence zone can be solved by the way of 'kriging'. The thesis gives numerous examples of the various numerical parameters, characteristics of an uranium deposit (absolute dispersion coefficient) or of an uranium ore (liberation parameter) as well as a few examples of linear correlations between gamma radioactivity and uranium grade. Three complete examples of reserve evaluation are given. The end of the thesis deals with the notion of ruin risk which has to be taken in some cases. A detailed alphabetical index is

  10. Hydrology of uranium deposits in calcretes of western Australia

    International Nuclear Information System (INIS)

    Gaskin, A.J.; Butt, C.R.M.; Deutscher, R.L.; Horwitz, R.C.; Mann, A.W.

    1981-01-01

    Carnotite is the principal uranium mineral occurring in the calcreted trunk valleys of the ancient drainage system which extends over 400,000 sq km of south-western Australia. The calcretes, accumulations of calcium and magnesium carbonates up to 100 km long, 5 km wide, and 20 m thick, are discontinuous in character but act as aquifers for groundwaters of relatively low salinity that flow sluggishly to playa lakes. Catchment basins draining large areas of Precambrian granitic rocks can yield up to 200 parts per billion of uranium in the oxidizing environment of the water at shallow depth near the base of the calcretes. Where the product of the concentrations of active ion species of uranium, vanadium, and potassium exceeds the solubility product of carnotite, this mineral precipitates in fissures or between the carbonate and clay particles. Vanadium appears to be generally deficient in the upper levels of the aquifers; however, where it has been supplied at the required concentration from deeper reduced waters, forced up, for example, by a bar of resistant bedrock, carnotite mineralization has occurred. The incongruent dissolution of carnotite liberates vanadium preferentially. Some carnotite deposits currently are being leached and redeposited downstream. Where calcrete channels reach salt lakes, great increases in the activity of calcium and potassium promote further carnotite deposition by the decomplexing of uranyl carbonate complexes carried down the aquifers. Many areas of carnotite mineralization are now known. The largest, at Yeelirre, contains 46,000 MT of U 3 O 8 at an average grade of 0.15%. Extraction from the ore is hampered by the carbonate content and the presence of illite-montmorillonite clay phases, but alkaline leach techniques are practicable. An appreciable proportion of the carnotite, in an extremely fine-grained form, can be associated with the clay fraction

  11. Methods of exploitation of different types of uranium deposits

    International Nuclear Information System (INIS)

    2000-09-01

    Deposits are mined using three broad types of mining methods: open pit, underground and in situ leaching. This publication addresses all aspects of mining and milling methods for several types of deposits and provides information to assist in the selection process of methods and also considers what actions must be taken into account for obtaining regulatory approvals for a project and for final decommissioning and reclamation of a project. The objective of this publication is to provide a process of selections of methods for mining engineers and managers involved in modernising ongoing operations or considering opening new operations. Several practical examples are given. These guidelines can be consulted and used in many countries involved in uranium mining and milling operations. The examples where costs are given can also be adjusted to specific economic conditions of various countries. The authors are from four uranium producing countries. They bring diversified experience for all types of mining and milling operations from tile opening of a mine to the decommissioning of the complete operation

  12. A method of quantitative prediction for sandstone type uranium deposit in Russia and its application

    International Nuclear Information System (INIS)

    Chang Shushuai; Jiang Minzhong; Li Xiaolu

    2008-01-01

    The paper presents the foundational principle of quantitative predication for sandstone type uranium deposits in Russia. Some key methods such as physical-mathematical model construction and deposits prediction are described. The method has been applied to deposits prediction in Dahongshan region of Chaoshui basin. It is concluded that the technique can fortify the method of quantitative predication for sandstone type uranium deposits, and it could be used as a new technique in China. (authors)

  13. Radon flux from rehabilitated and unrehabilitated uranium mill tailings deposits

    International Nuclear Information System (INIS)

    Sonter, M.; Akber, R.; Holdsworth, S.

    2002-01-01

    Radon release from uranium tailings deposits was identified in UNSCEAR 1993 as the main potential source of collective dose to the world population from the use of nuclear power (rather than, say, gamma doses to power plant workers, or doses to reprocessing plant workers or to waste-handling workers, or residents living adjacent to these facilities). This is due primarily to the ongoing nature of the radon releases over geological time and to the assumption of a 10,000 year integration time. UNSCEAR 1993 estimated 150 person-sieverts per GWe-yr of produced power, based on some very general assumptions about area of tailings per unit of uranium produced, uranium usage per unit of power produced, radon emanation per unit surface area of tails, population density within 100 km of the site, and from 100 km out to 2000 km from the site, and atmospheric dispersion. It should be noted at the outset that the idea of adding vanishingly small doses across the entire world population and integrating for 10,000 years into the future, to obtain a collective dose which is then used to infer induced cancer deaths, is warned against by ICRP, and more strongly disavowed in recent papers by Roger Clarke, as being unrepresentative of any real risk and a recipe for misallocation of resources. These UNSCEAR assumptions and the resulting estimations of collective dose were reviewed by SENES Consultants Ltd of Canada, in a report commissioned by the Uranium Institute, both in terms of the methodology and in terms of the factors used. In this report SENES substituted its best estimate assumptions, based on responses received from major commercial uranium mining operations for UNSCEAR's assumptions, which it identified as highly pessimistic, and arrived at a putative collective dose of about 1 person-sievert/ GWe-yr. The most recent UNSCEAR 2000 report acknowledges the uncertainty in the figures, and references the SENES report as providing more specific (but still limited) data. Taking on

  14. Uranium

    International Nuclear Information System (INIS)

    Villarreal, E.

    1986-01-01

    After the increase in oil prices in 1973, several European countries increased their power programs. As a result some uranium mining companies from the FRG, Spain and France invested in exploration of radioactive minerals in Colombia hoping to find uranium resources needed to fuel European reactors. In the article a historic review of foreign investment in uranium in Colombia is made; some recommendations about joint-venture contracts used to regulate the work of the foreign companies are included. The four companies involved in exploration left the country in the early eighties, due to the difficulties in finding a large deposit and the difficult world situation of nuclear power

  15. Mineralization enrichment of uranyl mineral in mid-low temperature hydrothermal of Shuanghuajiang uranium deposit

    International Nuclear Information System (INIS)

    Fang Shiyi; Liang Yongdong; Tao Zhijun; Chen Weifeng

    2009-01-01

    Based on field examination and mineral study by X-ray powder diffraction, electronic probe and back scatter electronic image, uranium mineral in Shuanghuajiang uranium deposit are analyzed and the mineral are divided into two classes: uranyl phosphate and uranyl silicate. After studying the forming condition of these uranylminerals, the deposit fall into low temperature hydrothermal genesis. The metallogenic model is hence established. (authors)

  16. Athabasca basin unconformity-type uranium deposits. A special class of sandstone-type deposits

    International Nuclear Information System (INIS)

    Hoeve, J.

    1980-01-01

    Two major episodes of uranium metallogenesis are recognized in Northern Saskatchewan. The first is of late-Hudsonian age and gave rise to metamorphic-hydrothermal pitchblende deposits of simple mineralogy at Beaverlodge (primary mineralization: 1780+-20 m.y.). The second and more important episode of approximately Grenvillian age rendered unconformity-type deposits in the Athabasca Basin (primary mineralization: 1000-1300 m.y.). The late-Hudsonian deposits at Beaverlodge were overprinted by this second event and new deposits of complex mineralogy were formed in that area. The metallogenetic importance of a third and much later episode which gave rise to mineralization within the Athabasca Formation is uncertain at the moment. With regards to metallogenesis of the unconformity-type deposits, presently available evidence favours a diagenetic-hydrothermal rather than a near-surface supergene or a magmatic/metamorphic hydrothermal model. The diagenetic-hydrothermal model relates uranium mineralization to 'red bed-type' diagenetic processes in the Athabasca Formation involving post-depositional oxidation and leaching, which continued for several hundred million years after deposition. Ore deposits were formed by interaction, under conditions of deep burial at elevated temperatures and pressures, of a uraniferous oxidizing Athabasca aquifer with reducing, graphite-bearing, metamorphic rocks of the basin floor. The large-scale convection required for such interaction may have been induced by mafic magmatic activity coeval with the episode of mineralization. The diagenetic-hydrothermal model displays close similarities with metallogenetic models developed for certain sandstone-type deposits. (author)

  17. Laboratory investigations of refractory uranium minerals from the Kvanefjeld uranium deposit, Greenland

    International Nuclear Information System (INIS)

    Rose-Hansen, J.; Soerensen, H.; Makovicky, M.; Konnerup-Madsen, J.; Holm, P.M.

    1982-01-01

    The project described in this report is a contribution to a large project on the beneficiation of the Kvanefjeld uranium deposit in the Ilimaussaq intrusion in South Greenland. The main object of our project has been to undertake laboratory experiments on steenstrupine in order to define the optimum extraction conditions. A pressurized carbonate leaching method was introduced. The Risoe experiments are carried out on bulk samples of the ore while we decided to study the minerals, first of all steenstrupine, and carbonate solutions as leaching media. Our experiments demonstrated that the leaching conditions arrived at by the Risoe group give the highest recovery and thus may be termed the optimum conditions using sodium carbonate leaching methods. Studies of the solid products left after the leaching experiments by means of the electron microprobe show that the grains of steenstrupine remain and that the leaching of uranium proceeds from the margins of the grains and towards their interior. We decided also to study the effect of applying ammonium sulphate solutions. These gave significantly higher recoveries. We consider the results of the experiments using ammonium sulphate solutions as an essential new information on the extractability of the Kvanefjeld ore and as a main result of our study. It is demonstrated that in the 13 types of rocks examined, including lujavrites, 25-75 % of the thorium and 2-58 % of the uranium contained in the rocks can be leached out and are thus not firmly bound in the minerals. (author)

  18. An exploration systems approach to the Copper Mountain uranium deposits, Wyoming, USA

    International Nuclear Information System (INIS)

    Babcock, L.L.; Sayala, D.

    1982-01-01

    This study of Copper Mountain uranium deposits entailed the examination, interpretation, and synthesis of geological, geochemical, geophysical, and emanometric results. Regional, structural, and metallogenic syntheses yielded criteria concerning the occurrence of anomalously radioactive granites and associated uranium deposits. Geochemical surveys indicated various pathfinder elements for uranium deposits and defined the extent of the anomalous granites. Subsurface spectral radiometrics outlined high K-Th zones which contain secondary uranium deposits. Aerial spectral radiometric and magnetic surveys delineated the Copper Mountain uranium district. Ground water helium and U-234/U-238 activity ratios are the most effective emanometric and isotopic techniques. Based on the systems approach employed and logistical considerations, a five-phase exploration strategy is suggested for Copper Mountain-type deposits

  19. An oxygen isotope study on hydrothermal sources of granite-type uranium deposits in South China

    International Nuclear Information System (INIS)

    Yongfei, Z.

    1987-01-01

    The usefulness of oxygen isotope measurements in solving problems of hydrothermal sources has been demonstrated in a number of detailed studies of the granite type uranium deposits in this paper. Remarkly the granite-type uranium deposits in Southr China have been shown to have formed from magmatic water, meteoric water, of mixtures of both the above, and origin of waters in the ore-forming fluid may be different for differing uranium deposits ore differing stages of the mineralization. Consequences obtained in this study for typical uranium deposits of different age and geologic sitting agree well with that obtained by other geologic-geochemical investigation. Furthermore, not only meteoric water is of importance to origin and evolution of the ore-forming fluid, but also mixing of waters from different sources is considered to be one of the most characteristic features of many hydrothermal uranium deposits related to granitoids or volcanics. (C.D.G.) [pt

  20. Pb-Sr-Nd isotopes in surficial materials at the Pebble Porphyry Cu-Au-Mo Deposit, Southwestern Alaska: can the mineralizing fingerprint be detected through cover?

    Science.gov (United States)

    Ayuso, Robert A.; Kelley, Karen D.; Eppinger, Robert G.; Forni, Francesca

    2013-01-01

    The Cretaceous Pebble porphyry Cu-Au-Mo deposit is covered by tundra and glacigenic sediments. Pb-Sr-Nd measurements were done on sediments and soils to establish baseline conditions prior to the onset of mining operations and contribute to the development of exploration methods for concealed base metal deposits of this type. Pebble rocks have a moderate range for 206Pb/204Pb = 18.574 to 18.874, 207Pb/204Pb = 15.484 to 15.526, and 208,Pb/204Pb = 38.053 to 38.266. Mineralized granodiorite shows a modest spread in 87Sr/86Sr (0.704354–0.707621) and 143Nd/144Nd (0.512639–0.512750). Age-corrected (89 Ma) values for the granodiorite yield relatively unradiogenic Pb (e.g., 207Pb/204Pb 87Sr/86Sr, and positive values of ɛNd (1.00–4.52) that attest to a major contribution of mantle-derived source rocks. Pond sediments and soils have similar Pb isotope signatures and 87Sr/86Sr and 143Nd/144Nd values that resemble the mineralized granodiorites. Glacial events have obscured the recognition of isotope signatures of mineralized rocks in the sediments and soils. Baseline radiogenic isotope compositions, prior to the onset of mining operations, reflect natural erosion, transport and deposition of heterogeneous till sheets that included debris from barren rocks, mineralized granodiorite and sulfides from the Pebble deposit, and other country rocks that pre- and postdate the mineralization events. Isotopic variations suggest that natural weathering of the deposit is generally reflected in these surficial materials. The isotope data provide geochemical constraints to glimpse through the extensive cover and together with other geochemical observations provide a vector to concealed mineralized rocks genetically linked with the Pebble deposit.

  1. Uniform deposition of uranium hexafluoride (UF6): Standardized mass deposits and controlled isotopic ratios using a thermal fluorination method

    Energy Technology Data Exchange (ETDEWEB)

    McNamara, Bruce K.; O’Hara, Matthew J.; Casella, Andrew M.; Carter, Jennifer C.; Addleman, R. Shane; MacFarlan, Paul J.

    2016-07-01

    Abstract: We report a convenient method for the generation of volatile uranium hexafluoride (UF6) from solid uranium oxides and other uranium compounds, followed by uniform deposition of low levels of UF6 onto sampling coupons. Under laminar flow conditions, UF6 is shown to interact with surfaces within the chamber to a highly predictable degree. We demonstrate the preparation of uranium deposits that range between ~0.01 and 470±34 ng∙cm-2. The data suggest the method can be extended to creating depositions at the sub-picogram∙cm-2 level. Additionally, the isotopic composition of the deposits can be customized by selection of the uranium source materials. We demonstrate a layering technique whereby two uranium solids, each with a different isotopic composition, are employed to form successive layers of UF6 on a surface. The result is an ultra-thin deposit of UF6 that bears an isotopic signature that is a composite of the two uranium sources. The reported deposition method has direct application to the development of unique analytical standards for nuclear safeguards and forensics.

  2. The geology and geochemistry of some epigenetic uranium deposits near the Swakop River, South West Africa

    International Nuclear Information System (INIS)

    Hambleton-Jones, B.B.

    1983-10-01

    This study comprises a geological and geochemical investigation of the uranium deposits in the region near the Swakop River which extends from the Langer Heinrich Mountain in the east to the end of the Tumas River in the west. The general geology of the basement rocks in the Langer Heinrich region only is discussed. The general geology of the younger duricrust formations is discussed. Analytical methods were developed for the separation of thorium, protactinium and uranium from geological materials using various chromatographic procedures. Alpha spectrometry, neutron activation analysis and delayed neutron counting were the main techniques used. The occurrence of uranium in the region of study follows a unique geochemical cycle, and the geochemistry at each stage in the cycle was examined. The first stage in the uranium-geochemical cycle was the basement rocks. The second stage in the geochemical cycle of uranium was the subsurface water. The third stage in the geochemical cycle of uranium concerns its occurrence in the duricrust deposits. Isotopic disequilibrium measurements showed that uranium is still migrating, and that the age of the carnotite precipitation is 30 000 years, based on the open-system model of uranium migration. In the final stage of the geochemical cycle, the geochemistry of uranium in seawater and the diatomaceous muds is discussed. A classification system for the uranium deposits near the Swakop River, based on genetic relationships, is proposed and described in terms of the geochemical cycle of uranium, the mode of transport and mode of deposition. The relationships between the duricrust uranium deposits and the other uranium deposits of South Africa are compared

  3. Uranium-series constraints on radionuclide transport and groundwater flow at the Nopal I uranium deposit, Sierra Pena Blanca, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, S.J.; Abdel-Fattah, A.I.; Murrell, M.T.; Dobson, P.F.; Norman, D.E.; Amato, R.S.; Nunn, A. J.

    2009-10-01

    Uranium-series data for groundwater samples from the Nopal I uranium ore deposit were obtained to place constraints on radionuclide transport and hydrologic processes for a nuclear waste repository located in fractured, unsaturated volcanic tuff. Decreasing uranium concentrations for wells drilled in 2003 are consistent with a simple physical mixing model that indicates that groundwater velocities are low ({approx}10 m/y). Uranium isotopic constraints, well productivities, and radon systematics also suggest limited groundwater mixing and slow flow in the saturated zone. Uranium isotopic systematics for seepage water collected in the mine adit show a spatial dependence which is consistent with longer water-rock interaction times and higher uranium dissolution inputs at the front adit where the deposit is located. Uranium-series disequilibria measurements for mostly unsaturated zone samples indicate that {sup 230}Th/{sup 238}U activity ratios range from 0.005-0.48 and {sup 226}Ra/{sup 238}U activity ratios range from 0.006-113. {sup 239}Pu/{sup 238}U mass ratios for the saturated zone are <2 x 10{sup -14}, and Pu mobility in the saturated zone is >1000 times lower than the U mobility. Saturated zone mobility decreases in the order {sup 238}U{approx}{sup 226}Ra > {sup 230}Th{approx}{sup 239}Pu. Radium and thorium appear to have higher mobility in the unsaturated zone based on U-series data from fractures and seepage water near the deposit.

  4. Uranium-series constraints on radionuclide transport and groundwater flow at the Nopal I uranium deposit, Sierra Pena Blanca, Mexico.

    Science.gov (United States)

    Goldstein, Steven J; Abdel-Fattah, Amr I; Murrell, Michael T; Dobson, Patrick F; Norman, Deborah E; Amato, Ronald S; Nunn, Andrew J

    2010-03-01

    Uranium-series data for groundwater samples from the Nopal I uranium ore deposit were obtained to place constraints on radionuclide transport and hydrologic processes for a nuclear waste repository located in fractured, unsaturated volcanic tuff. Decreasing uranium concentrations for wells drilled in 2003 are consistent with a simple physical mixing model that indicates that groundwater velocities are low ( approximately 10 m/y). Uranium isotopic constraints, well productivities, and radon systematics also suggest limited groundwater mixing and slow flow in the saturated zone. Uranium isotopic systematics for seepage water collected in the mine adit show a spatial dependence which is consistent with longer water-rock interaction times and higher uranium dissolution inputs at the front adit where the deposit is located. Uranium-series disequilibria measurements for mostly unsaturated zone samples indicate that (230)Th/(238)U activity ratios range from 0.005 to 0.48 and (226)Ra/(238)U activity ratios range from 0.006 to 113. (239)Pu/(238)U mass ratios for the saturated zone are 1000 times lower than the U mobility. Saturated zone mobility decreases in the order (238)U approximately (226)Ra > (230)Th approximately (239)Pu. Radium and thorium appear to have higher mobility in the unsaturated zone based on U-series data from fractures and seepage water near the deposit.

  5. Metallogenic geologic prerequisites of sandstone-type uranium deposits and target area selection. Taking Erlian and Ordos basins as examples

    International Nuclear Information System (INIS)

    Chen Fazheng

    2002-01-01

    Sandstone-type uranium deposit is the main target of recent uranium prospecting and exploration. According to the metallogenic characteristics, sandstone-type uranium deposits are divided into three groups: paleo-channel type, interlayer oxidation zone type and phreatic interlayer oxidation type. The author makes an analysis on the geologic prerequisites of the three types of uranium deposits, the similarities and difference, and preliminarily summarizes genetic models of different types of uranium deposits. Finally, taking Erlian and Ordos basins as examples, the author makes an evaluation and a strategic analysis on the uranium metallogenic prospect of the above two basins

  6. Interpretasi Deposit Uranium Berdasarkan Data Tahanan Jenis dan Polarisasi Terinduksi di Sektor Rabau Hulu

    Directory of Open Access Journals (Sweden)

    Dwi Haryanto

    2015-11-01

    Full Text Available Rabau Hulu area, Kalan, Kalimantan Barat is a potential area of uranium that has been explored in detail by various methods. Methods of resistivity and induced polarization can be applied in the exploration of uranium deposits in which its mineralization associated with sulphide minerals. Processing, analysis, and interpretation of resistivity and induced polarization data conducted in order to identify the distribution of uranium deposits and lithology of the rocks in the study area. Uranium deposits in the area Rabau Hulu is generally associated with sulphides, tourmaline and contained in favorable rocks. Symptoms of uranium mineralization encountered in other forms of irregular and uneven consists of uraninite, pyrite, chalcopyrite, pyrrhotite, molybdenite, and ilmenite minerals. Data acquisition using dipole-dipole configuration in an area of ​​approximately 36 hectares, 46 lines along + 425 m. Acquisition of induced polarization frequency domain data which the same points and lines with resistivity data. Data processing produces resistivity and metal factor values and subsequently made two-dimensional section. Determination of resistivity and induced polarization are done by correlated boreholes data with the results of data processing. Resistivity of uranium deposits zone worth less than 2,000 Ωm and the value of metal factor greater than 90 mho/m. Uranium deposit zone is expanding along with the depth. Uranium deposits distribution trending Southwestern-Northeast and shaped lens.

  7. Geological and geochemical aspects of uranium deposits: a selected, annotated bibliography

    International Nuclear Information System (INIS)

    Thomas, J.M.; Garland, P.A.; White, M.B.; Daniel, E.W.

    1980-09-01

    This bibliography, a compilation of 474 references, is the fourth in a series compiled from the National Uranium Resource Evaluation (NURE) Bibliographic Data Base. This data base was created for the Grand Junction Office of the Department of Energy's National Uranium Resource Evaluation Project by the Ecological Sciences Information Center, Oak Ridge National Laboratory. The references in the bibliography are arranged by subject category: (1) geochemistry, (2) exploration, (3) mineralogy, (4) genesis of deposits, (5) geology of deposits, (6) uranium industry, (7) geology of potential uranium-bearing areas, and (8) reserves and resources. The references are indexed by author, geographic location, quadrangle name, geoformational feature, and keyword

  8. Geological and geochemical aspects of uranium deposits: a selected, annotated bibliography. [474 references

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J.M.; Garland, P.A.; White, M.B.; Daniel, E.W.

    1980-09-01

    This bibliography, a compilation of 474 references, is the fourth in a series compiled from the National Uranium Resource Evaluation (NURE) Bibliographic Data Base. This data base was created for the Grand Junction Office of the Department of Energy's National Uranium Resource Evaluation Project by the Ecological Sciences Information Center, Oak Ridge National Laboratory. The references in the bibliography are arranged by subject category: (1) geochemistry, (2) exploration, (3) mineralogy, (4) genesis of deposits, (5) geology of deposits, (6) uranium industry, (7) geology of potential uranium-bearing areas, and (8) reserves and resources. The references are indexed by author, geographic location, quadrangle name, geoformational feature, and keyword.

  9. The Kayelekera uranium deposit, northern Malawi : past exploration activities, economic geology and decay series disequilibrium

    OpenAIRE

    Bowden, R.A.; Shaw, Richard

    2007-01-01

    The present paper describes the exploration and evaluation work carried out by the Central Electricity Generating Board on the Kayelekera uranium deposit in Northern Malawi between 1983 and 1991. This is one of the largest Karoo age sandstone hosted uranium deposits yet discovered. Approximately 200 boreholes, y60% of which were fully cored, were drilled into the deposit during this evaluation. An important part of the ore reserve estimation undertaken by the Central Electricit...

  10. Depending on scientific and technological progress to prospect for superlarge uranium deposits. Across-century target for uranium resources exploration work in China

    International Nuclear Information System (INIS)

    Shen Feng

    1995-01-01

    After over 30 years' development, uranium resources exploration work in China has resulted in the discovery of more than 10 economic types of uranium deposits in 23 provinces (regions) of the whole country and large quantities of uranium reserves have been submitted which guarantee the development of nuclear industry in China. However, characteristics such as smaller size of deposits and ore bodies, and lower ore grade of discovered China's uranium deposits have brought about a series of problems on how to economically exploit and utilize these uranium resources. To prospect for superlarge uranium deposits is a guarantee of making uranium resources essentially meet the demand for the long-term development of nuclear industry in China, and is an important way of improving economic benefits in mining China's uranium resources. It is an important mark for uranium geological exploration work to go up a new step as well. China exhibits the geological environment in which various types of superlarge uranium deposits can be formed. Having the financial support from the state to uranium resources exploration work, having professional uranium exploration teams well-experienced in ore prospecting, having modernized uranium exploration techniques and equipment and also having foreign experience in prospecting for superlarge uranium deposits as reference, it is entirely possible to find out superlarge uranium deposits in China at the end of this century and at the beginning of next century. In order to realize the objective, the most important prerequisite is that research work on metallogenetic geological theory and exploration techniques and prospecting methodology for superlarge uranium deposits must be strengthened, and technical quality of the geological teams must be improved. Within this century, prospect targets should be selected and located accurately to carry out the emphatic breakthrough in exploration strategy

  11. Regional metallogenic essential factor of granite-type uranium deposits in Guangdong province

    International Nuclear Information System (INIS)

    Pan Yongzheng

    1987-12-01

    The uranium origin, activation region, red basin, and fault depressed zone constitute the regional metallogenic essential factor of the four united like one granite-type uranium deposits in the post-Caledonian rise area in China. In the development of sub-geosyncline in the Caledonian, the clastic formation with widely deposited carbon, silicon, mud rich bearing organic matter, which drow a great amount of uranium formed the uranium-bearing system in the Sinian-Cambrian period. The magmagranite activation in a large scale in the Indosinian-Yenshanian period caused the continental crust to be suffered strong reformation and the uranium-bearing basement system to be eroded and remelted, and formed the rich uranium granite body. The multiple structure-magmatic movement further made the uranium in the rock body suffered the endogenic, structure, supergene active reformation, and produced mobile uranium concentrated area. Under the dry and hot paleoclimate condition in the Cretaceous-Tertiary period, strong weathering and hot water leaching forced uranium to be concentrated into the 'rock origin activation' type uranium deposits in the fault depressed zone

  12. Geology and recognition criteria for uraniferous humate deposits, Grants Uranium Region, New Mexico. Final report

    International Nuclear Information System (INIS)

    Adams, S.S.; Saucier, A.E.

    1981-01-01

    The geology of the uraniferous humate uranium deposits of the Grants Uranium Region, northwestern New Mexico, is summarized. The most important conclusions of this study are enumerated. Although the geologic characteristics of the uraniferous humate deposits of the Grants Uranium Region are obviously not common in the world, neither are they bizarre or coincidental. The source of the uranium in the deposits of the Grants Uranium Region is not known with certainty. The depositional environment of the host sediments was apparently the mid and distal portions of a wet alluvial fan system. The influence of structural control on the location and accumulation of the host sediments is now supported by considerable data. The host sediments possess numerous important characteristics which influenced the formation of uraniferous humate deposits. Ilmenite-magnetite distribution within potential host sandstones is believed to be the simplest and most useful regional alteration pattern related to this type of uranium deposit. A method is presented for organizing geologic observations into what is referred to as recognition criteria. The potential of the United States for new districts similar to the Grants Uranium Region is judged to be low based upon presently available geologic information. Continuing studies on uraniferous humate deposits are desirable in three particular areas

  13. National uranium resource evaluation. Geology and recognition criteria for sandstone uranium deposits of the salt wash type, Colorado Plateau Province. Final report

    International Nuclear Information System (INIS)

    Thamm, J.K.; Kovschak, A.A. Jr.; Adams, S.S.

    1981-01-01

    The uranium-vanadium deposits of the Salt Wash Member of the Morrison Formation in the Colorado Plateau are similar to sandstone uranium deposits elsewhere in the USA. The differences between Salt Wash deposits and other sandstone uranium deposits are also significant. The Salt Wash deposits are unique among sandstone deposits in that they are dominantly vanadium deposits with accessory uranium. The Salt Wash ores generally occur entirely within reduced sandstone, without adjacent tongues of oxidized sandstone. They are more like the deposits of Grants, which similarly occur in reduced sandstones. Recent studies of the Grants deposits have identified alteration assemblages which are asymmetrically distributed about the deposits and provide a basis for a genetic model for those deposits. The alteration types recognized by Shawe in the Slick Rock district may provide similar constraints on ore formation when expanded to broader areas and more complete chemical analyses

  14. Thermoluminescence applied to uranium exploration and genesis of the Westmoreland uranium deposits - implications for the Northern Territory

    International Nuclear Information System (INIS)

    Hochman, M.B.M.; Ypma, P.J.M.

    1984-01-01

    The Westmoreland uranium deposits occur on the northern flank of the Murphy Tectonic Ridge in the upper member of the Westmoreland Conglomerate. Uranium mineralisation is spatially associated with the contact of the overlying basaltic Siegal Volcanics and the margins of intrusive dolerite dykes which are geochemically similar to the Siegal Volcanics. Thermoluminescence measurements on 800 samples from within the orebodies and surrounding host rock have indicated that all of the Westmoreland Conglomerate has suffered major radiation damage attributable to at least 10 ppm uranium over 10 9 years. The underlying rhyolitic Mid Proterozoic Cliffdale Volcanics have distinctive TL glow curves indicative of radiation sensitisation caused by high uranium contents. These volcanics are part of the Mid Proterozoic volcanic event known to be enriched in uranium. The Westmoreland Conglomerate has been derived by erosion of the uranium-rich Cliffdale Volcanics and associated Nicholson Granite Complex which makes it likely that the Westmoreland Conglomerate had a high inherent uranium content. It is proposed that this precontained uranium within the Westmoreland Conglomerate was remobilized in a convective cell system possibly triggered by intrusion of dolerite dykes, or by a later rejuvenation of vertical structures which provided an ascending heat flow. Pitchblende was precipitated where suitable reducing conditions existed close to the basic volcanics and dykes

  15. Preliminary U-series disequilibrium and thermoluminescence ages of surficial deposits and paleosols associated with Quaternary fault, Eastern Yucca Mountain

    International Nuclear Information System (INIS)

    Paces, J.B.; Menges, C.M.; Bush, C.A.; Futa, K.; Millard, H.T.; Maat, P.B.; Whitney, J.W.; Widmann, B.; Wesling, J.R.

    1994-01-01

    Geochronological control is an essential component of paleoseismic evaluation of faults in the Yucca Mountain region. New U-series disequilibrium and thermoluminescence age estimates for pedogenic deposits that bracket surface-rupture events are presented from four sites exposing the Paintbrush Canyon, Bow Ridge and Stagecoach Road faults. Ages show an internal consistency with stratigraphic relationships as well as an overall concordancy between the two independent geochronometers. Age estimates are therefore interpreted to date depositional events or episodes of pedogenic carbonate mobility that can be used to establish a paleoseismic fault chronology. Ultimately, this type of chronological information will be used to evaluate seismic hazards at Yucca Mountain

  16. Preliminary U-series disequilibrium and thermoluminescence ages of surficial deposits and paleosols associated with Quaternary fault, Eastern Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Paces, J.B.; Menges, C.M.; Bush, C.A.; Futa, K.; Millard, H.T.; Maat, P.B.; Whitney, J.W. [Geological Survey, Denver, CO (United States); Widmann, B. [Science Applications International Corp., Golden, CO (United States); Wesling, J.R. [Geomatrix Consultants, Inc., San Francisco, CA (United States)

    1994-12-31

    Geochronological control is an essential component of paleoseismic evaluation of faults in the Yucca Mountain region. New U-series disequilibrium and thermoluminescence age estimates for pedogenic deposits that bracket surface-rupture events are presented from four sites exposing the Paintbrush Canyon, Bow Ridge and Stagecoach Road faults. Ages show an internal consistency with stratigraphic relationships as well as an overall concordancy between the two independent geochronometers. Age estimates are therefore interpreted to date depositional events or episodes of pedogenic carbonate mobility that can be used to establish a paleoseismic fault chronology. Ultimately, this type of chronological information will be used to evaluate seismic hazards at Yucca Mountain.

  17. Semantic discrimination of paleo-channel and paleo-valley sandstone-type uranium deposits

    International Nuclear Information System (INIS)

    Hou Mingcai

    2000-01-01

    By discriminating the characteristics of two different geo-morphological elements-stream channel and stream valley, the author tries to clear up the concept of paleo-channel sandstone-type uranium deposit and paleo-valley sandstone-type uranium deposit in the field of uranium geology. Moreover, the author also discusses the response of the stream channel and stream valley to the variation of erosion basis and characteristics of depositional sequence. The above-mentioned provides help for the determination of the distribution of paleo-channels on the plan

  18. Studies on geneses of Lianshanguan granites and Lianshanguan uranium ore deposit

    International Nuclear Information System (INIS)

    Zhang Jiafu; Xu Guoqing; Wang Wenguang

    1994-02-01

    Based on the field work, and through the studies of thin-sections, minerals fluid inclusions, isotope geology, rare-earth elements and U-content in rocks and minerals, it is suggested that Lianshanguan granites are of magmatization genesis with multistage. The genetic model of mineralization of Lianshanguan uranium ore deposit is the magmatization-hydrothermal-filled uranium type. The role of mineralization of uranium ore deposit in that area is discussed. Furthermore, the direction of prospecting and following prospecting criteria for similar deposits in this area are also given

  19. Depositional environments as a guide to uranium mineralization in the Chinle formation, San Rafael Swell, Utah

    International Nuclear Information System (INIS)

    Lupe, R.

    1977-01-01

    The sedimentary textures resulting from depositional processes operating in low-energy environments appear to have influenced uranium mineralization. The Chinle consists of three fining-upward, fluvial-lacustrine sequences. Uranium minerals are concentrated in the lower part of the lowest sequence in areas where sediments of low-energy environment are complexly interbedded with sediments of other environments. Areas favorable for uranium exploration exist in the subsurface to the north, west, and south of the Chinle outcrop in the Swell. This determination is based on the spatial distribution of depositional environments and the pattern of Chinle deposition through time. 8 refs

  20. Relationship between sandstone-type uranium deposits and hydrocarbon in the northern ordos basin

    Science.gov (United States)

    Wang, Feifei; Wang, Jianqiang; Guo, Pei; Cheng, Xianghu; Li, Bei; Song, Zisheng; Wei, Anjun

    2017-05-01

    The Ordos Basin is one of the largest proliferous basins and also one of the most important uranium-bearing basins in China. It is characterized by the coexistence of petroleum and uranium in the northern part of the basin. To understand the coexistence mechanism, more studies are called for on the genesis of sandstone-type uranium deposits in the northern part of the basin, especially on the role of hydrocarbon in uranium mineralization. In this study, we investigated the relationship between uranium and hydrocarbon in the northern Ordos Basin using the methods of petrology, mineralogy and geochemistry. Our results show that the hydrocarbon seepage plays an important role in the mineralization of sandstone-type uranium deposits. It greatly affects the reduction in mineralization and the environmental rehabilitation to protect the ore body from being destroyed by the groundwater after mineralization.

  1. Geological characteristics of the main deposits in the world. Geological characteristics of French uranium deposits; their consequences on the different stages of valorisation. The uranium market

    International Nuclear Information System (INIS)

    Gangloff, A.; Lenoble, A.; Mabile, J.

    1958-07-01

    This document gathers three contributions. In the first one, after having recalled data regarding uranium ore and metal reserves in Canada, USA, South Africa and France, the author describes and discusses the geological and mineral characteristics of the main deposits in Canada (Great Bear Lake, Ace-Verna and other deposits of the Beaverlodge district, Gunnar, Blind River and Bancroft), in the USA (New Mexico, Colorado and Arizona), and in South Africa (similar structure as observed in Blind River). The second contribution addresses the French uranium deposits by firstly presenting, describing and classifying vein deposits (five types are distinguished) and sedimentary deposits in different geological formations, and by secondly discussing the impacts of these characteristics on exploration, surface exploration works, and mining works. The third contribution proposes an overview of the uranium market: comments of world productions (conventional extraction processes and technical peculiarities, costs and prices, reserves and production in Canada, USA, South Africa, France, Australia and others), presentation of the French program (location and production capacity of uranium production plants, locations of ore extraction), overview of the current situation of the world market (price levels, possible prices after 1962), discussion of the comparison between demands and supplies, overview of the French uranium policy

  2. Discussion on geochemical characteristics, mechanism and prospecting model of gluey type sandstone uranium mineralization--taking Redwell uranium deposit as an example

    International Nuclear Information System (INIS)

    Wang Jinping

    1998-01-01

    Redwell uranium deposit hosted in the red clastic rock formation, is a typical example of gluey type uranium mineralization, which has not been reported so far in China. Based on the study of geochemical characteristics of Redwell deposit, the author discusses the genetic mechanism of this type deposits, and proposes the prospecting model of 4 in 1 of red bed-fault-oil gas-uranium source

  3. Irradiation defects in clayey minerals in association with discordance-type uranium deposit

    International Nuclear Information System (INIS)

    Morichon, E.; Beaufort, D.; Morichon, E.; Allard, Th.

    2009-01-01

    Radioactivity generates defects in minerals and these defects are the witnesses of the presence of radio-elements, and therefore represent an interesting potential for uranium prospecting. Investigations made in the Athabasca basin in Canada reveal irradiation defects in very old clays (kaolinite, illite and sudoite) in the alteration halo of discordance-type uranium deposits. The authors comment the defect concentration variation among the different drillings. These differences show that hexavalent uranium circulated in the whole geological system

  4. Using geological information to develop new exploration project for uranium deposits in Southern Africa

    International Nuclear Information System (INIS)

    Takahashi, Osamu

    1992-01-01

    Unconformity related uranium deposits which contain a large amount of resources with higher grades will be economically superior to other types of deposits. This paper presents the integrated use of geological information, which includes compilation data for the Precambrian geology in southern Africa and selected structural geologic data for some analogues of unconformity related uranium deposit in Canada (e.g. Key Lake deposit in Athabasca Basin) and the Precambrian rock hosted uranium deposit in Africa (e.g. Oklo-Munana, Rossing, Shinkolobwe and Dome deposits). Finally, some favourable geological terrains for unconformity related uranium deposit and the Precambrian rock hosted uranium deposit were selected on the basis of geological information. Further significant discoveries are likely in the following geological terrains. 1. Both the unconformity related and Oklo-Munana type deposits are favourable at (a) and (b). (a) the Lower Proterozoic Eburnian belts which are unconformably overlain by sequences of Kibaran and also the unmetamorphosed sequences in Pan-African. The age and paleoenvironment of the unmetamorphosed sequences in Pan-African is comparable to Kibaran. (b) the unmetamorphosed sequences in Eburnian. 2. The Rossing, Shinkolobwe and Dome type deposits are favourable at the Upper Proterozoic Pan-African Belts. (author)

  5. Age, sedimentary environments, and other aspects of sandstone and related host rocks for uranium deposits

    International Nuclear Information System (INIS)

    1983-01-01

    Project II of the Uranium Geology Working Group was assigned to the study of sedimentary basins and sandstone - type uranium deposits. About 40% of the worlds's uranium resources are contained in sandstone-type deposits, which has led to extensive research. The research was carried out mainly by correspondence, and the results reported by 21 geologists from 10 nations are summarized in this report. It investigated five topics dealing with important aspects of the geology of uranium ores in sandstone host formations: age of host rock; partitioning of uranium between continental and marine sediments; latitude limitation on formation of sandstone deposits; effect of rock formation dip on sandstone ores; usefulness of stable isotope and fluid inclusion studies. The results of studies on these subjects form part of a wider programme of the Working Group, whose final results will be presented at the 27th International Geological Congress in Moscow in 1984

  6. The Probability of Uranium Deposit Occurrences at Hatapang and Its Surrounding

    International Nuclear Information System (INIS)

    Soepradto-Tjokrokardono; Ngadenin

    2004-01-01

    This study was carried out based on a geological condition of Hatapang and is surroundings areas that are favourable for uranium accumulation, which are indicated by the existence of granite high uranium content, having mobilizations process and uranium trapping rocks. Referring to the plate tectonic and geochemical situation of Hatapang, those condition will give a significant indications for the possible occurrence of deposit of uranium in the area. The goal of this study is to know the probability occurrences of uranium deposit based on the regional tectonic, geology, mineralogy, geochemical, and radioactivity characters. It is concluded that Hatapang granite is potential for U source granite, and U deposit of black shale type is probably accurate in this area. (author)

  7. Electron energy deposition in a multilayered carbon--uranium--carbon configuration and in semi-infinite uranium

    International Nuclear Information System (INIS)

    Lockwood, G.J.; Miller, G.H.; Halbleib, J.A. Sr.

    1977-10-01

    Absolute measurements of electron energy deposition profiles are reported here for electrons incident on the multilayer configuration of carbon-uranium-carbon. These measurements were for normally incident source electrons at an energy of 1.0 MeV. To complement these measurements, electron energy deposition profiles were also obtained for electrons incident on semi-infinite uranium as a function of energy and angle of incidence. The results are compared with the predictions of a coupled electron/photon Monte Carlo transport model. In general, the agreement between theory and experiment is good. This work was in support of the Reactor Safety Research Equation-of-State Program

  8. Measures for waste water management from recovery processing of Zhushanxia uranium deposit

    International Nuclear Information System (INIS)

    Liu Yaochi; Xu Lechang

    2000-01-01

    Measures for waste water management from recovery processing of Zhushanxia uranium deposit of Wengyuan Mine is analyzed, which include improving process flow, recycling process water used in uranium mill as much as possible and choosing a suitable disposing system. All these can decrease the amount of waste water, and also reduce costs of disposing waste water and harm to environment

  9. Discussion on spatial emplacement of exogenic-epigenetic infiltration-type uranium deposit

    International Nuclear Information System (INIS)

    Zhao Fengmin

    2005-01-01

    Exogenic-epigenetic infiltration-type uranium deposit is a kind of deposit with large resources, low exploitation cost, and less environmental pollution being the recent important prospecting target in China. Prospecting practice for uranium during recent decade indicates that the metallogenic model and prospecting-evaluation criteria obtained from sandstone-hosted uranium deposits in Middle Asia are not applicable to the case in China. China is a country which has been subject to intense neotectonism, and Meso-Cenozoic basins in China have experienced various tectonic reworking. According to the spatial relation to orogenic belts sedimentary basins may be divided into: basins in orogenic belt; basins near orogenic belt and basins with weak tectonic activation far away from orogenic belt. Then, based on the structural features, basins may be further divided into corresponding subtypes. The author discusses the favourability of each type basin for the formation of exogenic-epigenetic uranium mineralization, as well as the paleo-climatic conditions for uranium ore-formation. Then, the author proposes that, for small intracontinental basins recharged by natural groundwater, the arid climatic period is not totally a favourable factor for uranium ore-formation, it even could be an unfavourable factor. In contrast, basins located in humid climatic region may be advantageous to uranium ore-formation. For improving the prospecting efficiency, a metallogenic model for exogenic-epigenetic infiltration uranium deposits and corresponding prospecting-evaluation criteria suitable for geologic situation of China have to be established as soon as possible. (authors)

  10. Aeromagnetic gradient survey and elementary application in sandstone type uranium deposits prospecting

    International Nuclear Information System (INIS)

    Li Xiaolu; Chang Shushuai

    2009-01-01

    The principle,advantage and data processing of aeromagnetic gradient survey approach is introduced in this paper, and used to identify the shallow surface faults, uranium ore-forming environment and depth of magnetic body for the prospecting of sandstone type uranium deposits. (authors)

  11. Physical, chemical, and mineralogical data from surficial deposits, groundwater levels, and water composition in the area of Franklin Lake playa and Ash Meadows, California and Nevada

    Science.gov (United States)

    Goldstein, Harland L.; Breit, George N.; Yount, James C.; Reynolds, Richard L.; Reheis, Marith C.; Skipp, Gary L.; Fisher, Eric M.; Lamothe, Paul J.

    2011-01-01

    This report presents data and describes the methods used to determine the physical attributes, as well as the chemical and mineralogical composition of surficial deposits; groundwater levels; and water composition in the area of Franklin Lake playa and Ash Meadows, California and Nevada. The results support studies that examine (1) the interaction between groundwater and the ground surface, and the transport of solutes through the unsaturated zone; (2) the potential for the accumulation of metals and metalloids in surface crusts; (3) emission of dust from metal-rich salt crust; and (4) the effects of metal-rich dusts on human and ecosystem health. The evaporation of shallow (surface. Ground-surface characteristics such as hardness, electrical conductivity, and mineralogy depend on the types and forms of these salt crusts. In the study area, salt crusts range from hard and bedded to soft and loose (Reynolds and others, 2009). Depending on various factors such as the depth and composition of groundwater and sediment characteristics of the unsaturated zone, salt crusts may accumulate relatively high contents of trace elements. Soft, loose salt crusts are highly vulnerable to wind erosion and transport. These vulnerable crusts, which may contain high contents of potentially toxic trace elements, can travel as atmospheric dust and affect human and ecosystem health at local to regional scales.

  12. Uranium distribution and sandstone depositional environments: oligocene and upper Cretaceous sediments, Cheyenne basin, Colorado

    International Nuclear Information System (INIS)

    Nibbelink, K.A.; Ethridge, F.G.

    1984-01-01

    Wyoming-type roll-front uranium deposits occur in the Upper Cretaceous Laramie and Fox Hills sandstones in the Cheyenne basin of northeastern Colorado. The location, geometry, and trend of specific depositional environments of the Oligocene White River and the Upper Cretaceous Laramie and Fox Hills formations are important factors that control the distribution of uranium in these sandstones. The Fox Hills Sandstone consists of up to 450 ft (140 m) of nearshore marine wave-dominated delta and barrier island-tidal channel sandstones which overlie offshore deposits of the Pierre Shale and which are overlain by delta-plain and fluvial deposits of the Laramie Formation. Uranium, which probably originated from volcanic ash in the White River Formation, was transported by groundwater through the fluvial-channel deposits of the White River into the sandstones of the Laramie and Fox Hills formations where it was precipitated. Two favorable depositional settings for uranium mineralization in the Fox Hills Sandstone are: (1) the landward side of barrier-island deposits where barrier sandstones thin and interfinger with back-barrier organic mudstones, and (2) the intersection of barrier-island and tidal channel sandstones. In both settings, sandstones were probably reduced during early burial by diagenesis of contained and adjacent organic matter. The change in permeability trends between the depositional strike-oriented barrier sandstones and the dip-oriented tidal-channel sandstones provided sites for dispersed groundwater flow and, as demonstrated in similar settings in other depositional systems, sites for uranium mineralization

  13. Attachment GEO 1 Permic basin geology in northeast of Uruguay: deposit exam about Uranium traces

    International Nuclear Information System (INIS)

    L'Homer, A.; Manigault, B; Doyhenart, A.; Rossi, P.

    1983-01-01

    The article is about different deposit of Uranium traces and their Sedimentology analysis. A revision of main works have been given and Durazno and Gondwana groups, Cerrezuelo, Cordobes, La Paloma, San Gregorio, Tres Islas formations

  14. The geological characteristics and forming conditions of granite type uranium-rich ore deposits

    International Nuclear Information System (INIS)

    Li Tiangang; Tong Hangshou; Feng Mingyue; Li Yuexiang; Xu Zhan

    1993-03-01

    The forming conditions and concentration mechanism of rich ore, criteria of ore prospecting and selection of uranium-rich ore target area are introduced in the article that is based on the studying of geological characteristics and conditions of granite type uranium-rich ore deposits of No 201 and 361 and on the comparisons of rich and poor ore deposits in geological conditions. Some new view points are also presented as the separate deposition of uranium minerals and gangue minerals is the main mechanism to form rich ore, for rich ore formation the ore enrichment by superimposition is not a universal regularity and most uranium-rich ore deposits are formed within one mineralization stage or mainly in one mineralization stage

  15. Study of finding out uranium deposit with geophysical methods at Zhongdong district Onyuan county Guangdong province

    International Nuclear Information System (INIS)

    Yang Yaxin; Wu Xinmin; Chen Yue; Zheng Yongming; Zhang Ye; Wang Tongjin

    2008-06-01

    The soil natural thermoluminescence measurement and radon survey were chosen, whose penetrability is stronger, and their applied effects were studied in prospecting uranium deposit at Xiazhuang granite area. The 236 stations were measured respectively with these two methods at Zhongdong district Ongyuan county Guangdong province. The research results show that: 1. There are good effects which fractured zones were found out with radon survey. 2. The soil natural thermoluminescence measurement is one of the cumulative measurement methods. It can obviously respond the projected position of uranium deposit of intersected point type. 3. The sensitivity, stability and reappearance of the soil natural thermoluminescence is good, and it was less affected by human activity on the surface. The measured anomalies can reflect the variety of the radioactive field, so amplitude and width of anomalies can basically respond the distribution of uranium ore body. The problems to be solved in the future are: If the rocks above the 'intersection point type' uranium deposits are relatively intact, how much depth can it be found out with soil natural thermoluminescence method? A set of nuclear geophysical prospecting pattern on the different types of uranium deposits in Xiazhuang uranium ore field should be summarized so that they can be used to find out uranium deposits in granite area in the future. (authors)

  16. Genetic-Structural relations in some types of spanish uranium deposits

    International Nuclear Information System (INIS)

    Alia Medina, M.

    1962-01-01

    On the spanish hercynian areas there are different types of uraniferous deposits, which may be classified in the following groups: Group I, high temperature magmatic deposits, Group II, low temperature veins and Group III supergenic deposits, generated by weathering of the former ones or by lixiviation of the intra granitic uranium. The deposits belonging to Group I are founding the hercynian ge anticlinal; those of Groups II and III, chiefly in the eugeosyncline. The explanation suggested for these genetic-structural relationships assumes that, in the ge anticlinal, uranium would migrate from the dioritic magmas to form and high temperature deposits. In the eugeosyncline, a large fraction of the uranium would migrate towards more differentiated granites, in which it might partially remain or from which it might have been finally concentrated in the epithermal veins or by later tectonic actions. The Group III deposits ar more frequent in the eugeosyncline, due to the greater abundance of more differentiated intrusive rocks. (Author) 16 refs

  17. Machine Learning Methods for Identifying Composition of Uranium Deposits in Kazakhstan

    Directory of Open Access Journals (Sweden)

    Kuchin Yan

    2017-12-01

    Full Text Available The paper explores geophysical methods of wells survey, as well as their role in the development of Kazakhstan’s uranium deposit mining efforts. An analysis of the existing methods for solving the problem of interpreting geophysical data using machine learning in petroleum geophysics is made. The requirements and possible applications of machine learning methods in regard to uranium deposits of Kazakhstan are formulated in the paper.

  18. Application of EH4 conductivity image system to sandstone type uranium deposits

    International Nuclear Information System (INIS)

    Wu Yue; Liu Hanbin; Dong Xiukong

    1998-01-01

    EH4 conductivity image system is a combined system of MT and CSAMT which can automatically acquire and process electromagnetic data. The author introduces its mechanism of measurement, data processing, and geological problems in prospecting sandstone type uranium deposits that the system can solve. The author also introduces some application achievements of the system in several known sandstone type uranium deposits in Yunnan province and Inner Mongolia Autonomous Region

  19. Discussion on several problems on the mineralization of paleo-channel sandstone type uranium deposits

    International Nuclear Information System (INIS)

    Huang Shijie

    1997-01-01

    On the basis of comprehensively analyzing paleo-channel sandstone type uranium deposits at home and abroad, the author discusses the division of mineralization types of paleo-channel sandstone type uranium deposits, and analyzes the metallogenic geologic conditions such as regional geologic background, climatic and geomorphological conditions, basement and sedimentary cover, characteristics of paleo-valley and paleo-channel, mineralization features as well as epigenetic metallogenic process. Future prospecting direction is also proposed

  20. Preliminary photointerpretation map of landslide and other surficial deposits of the Concord 15-minute quadrangle and the Oakland West, Richmond, and part of the San Quentin 7 1/2-minute quadrangles, Contra Costa and Alameda counties, California

    Science.gov (United States)

    Nilsen, T.H.

    1973-01-01

    This map presents preliminary information about one aspect of the physical environment necessary to sound land-use planning- the nature and distribution of surficial deposits.  Because surficial deposits are common and well developed in much of the bay region, it is useful to know how and why they have formed, as well as what properties they possess.  When maps like this are used in combinaion with other types of environmental information, such as data on soils, bedrock geology, slopes, vegetation, climatic variation, seismic response, and hydrology, it should be easier to arrive at sound decisions regarding the physical aspects of land use.  The U.S. Geological Survey is studying many of these factors in the bay region and hopes to provide the community with much of the required information as part of its San Francisco Bay Region Study in cooperation with the Department of Housing and Urban Development.

  1. Uranium

    International Nuclear Information System (INIS)

    Perkin, D.J.

    1982-01-01

    Developments in the Australian uranium industry during 1980 are reviewed. Mine production increased markedly to 1841 t U 3 O 8 because of output from the new concentrator at Nabarlek and 1131 t of U 3 O 8 were exported at a nominal value of $37.19/lb. Several new contracts were signed for the sale of yellowcake from Ranger and Nabarlek Mines. Other developments include the decision by the joint venturers in the Olympic Dam Project to sink an exploration shaft and the release of an environmental impact statement for the Honeymoon deposit. Uranium exploration expenditure increased in 1980 and additions were made to Australia's demonstrated economic uranium resources. A world review is included

  2. Solubility constraints on uranium concentrations in groundwaters of the tono uranium deposit, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Iwatsuki, T.; Ota, K. [Japan Nuclear Cycle Development Inst. (JNC), Gifu (Japan); Arthur, R. [Monitor Scientific, LLC, Denver, CO (United States); Metcalfe, R. [Quintessa, Japan, Kanagawa (Japan)

    2004-07-01

    A key concept underpinning most safety assessments of geological disposal systems for high-level nuclear wastes is that the maximum aqueous concentrations of actinide elements released from the waste will be limited by the solubility of the corresponding tetravalent oxide or hydrous oxide. The validity of this concept for U is evaluated in the present study using hydrochemical and mineralogical data from the tono uranium (U) deposit in gifu prefecture, Japan. In addition, the long-term stability of U mineralization in the tono deposit is assessed in terms of plausible range of U solubilities in paleogroundwaters migrating through the deposit. A thermodynamic evaluation of the aqueous-speciation and solubility behaviour of U indicates that U concentrations in the coexisting groundwaters greatly exceed the solubility of both uraninite [UO{sub 2}(c)] and coffinite [USiO{sub 4}(c)]. The dissolved U concentrations appear instead to be controlled by the solubility of amorphous hydrous U(IV) oxide [UO{sub 2}(am)], which is metastable with respect to uraninite. Mineralogical and microbiological investigations suggest that pH-E{sub h} conditions similar to those observed presently in groundwaters of the lower toki lignite-bearing formation (pH {approx} 8-10; E{sub h} {approx} -250--410 mV) have been buffered, possibly since the present geological structure formed about 5-0.7 Ma, by microbial sulphate reduction and precipitation/dissolution of calcite. If so, corresponding U concentrations controlled by UO{sub 2}(am) solubility are calculated to have been in the range of 10{sup -6.1} and 10{sup -8.7} mol kg{sup -1} depending on the possible environmental conditions, i.e., E{sub h}, pH and carbonate concentration. (orig.)

  3. Criteria for uranium occurrences in Saskatchewan and Australia as guides to favorability for similar deposits in the United States

    International Nuclear Information System (INIS)

    Kalliokoski, J.; Langford, F.F.; Ojakangas, R.W.

    1978-07-01

    The objective of this study was to explain the occurrence of the large uranium deposits that have been found in northern Saskatchewan and the Northern Territory of Australia, to provide criteria to evaluate the favorability of Proterozoic rocks in the United States for similar deposits. All of these deposits belong to the class known as the Proterozoic unconformity-type pitchblende deposits. Chapters are devoted to: uranium deposits in Saskatchewan; uranium deposits of the Darwin and Arnhem Land area, Northern Territory of Australia; model for the Proterozoic unconformity-type pitchblende deposits; and evaluation of the geology of selected states for its favorability for Proterozoic unconformity-type pitchblende deposits

  4. In situ carbonate leaching and recovery of uranium from ore deposits

    International Nuclear Information System (INIS)

    Hunkin, G.G.; Fife, T.P.; Stano, J.R.

    1979-01-01

    Uranium is leached from redox roll ore deposits by selective in-situ leaching with a solution of pH 7.4 to 9 (preferably 7.5 to 8.5) containing from about 0.5 to 5g/l of NH 4 HCO 3 and from about 0.1 to 3g/l of peroxide (preferably aqueous H 2 O 2 ), and sufficient NH 3 to maintain the desired pH. The leach solution is then withdrawn from the ore deposit and contacted with a strong base anion exchange material to strip the uranium from the leach solution. The uranium is eluted from the anion exchange material by an aqueous eluant, and the uranium is recovered from the eluate by first acidifying it and then treating it with ammonia to produce a precipitate of relatively pure ammonium diuranate. The content of the three components in the stripped leach solution is adjusted, and then the leach solution is recirculated through the ore deposit. After the uranium ore is removed to the extent economically practicable, the leach solution is replaced with an aqueous reducing solution which when passed into the ore deposit precipitates and renders insoluble any uranium and elements such as vanadium, molybdenum, and selenium. This process produces above ground a very low volume of impurities and waste solutions requiring disposal and does not cause material contamination of the underground deposit or any aquifer associated with the deposit

  5. Evaluation of Uranium depositional system in sedimentary rocks of Sibolga formation, Tapanuli Tengah

    International Nuclear Information System (INIS)

    I Gde Sukadana; Heri Syaeful

    2016-01-01

    Uranium in nature formed in various deposit type, depends on its sources, process, and depositional environments. Uranium occurrence in Sibolga, hosted in sedimentary rocks of Sibolga Formation, is properly potential to develop; nevertheless, the depositional pattern and uranium mineralization process so far had not been recognized. The research aim is to determine the rock distribution patterns and the existence of uranium grade anomalies based on surface geology and borehole log data. Mineralization occurrences from borehole log data distributed from basalt conglomerate unit (Kgl 1), sandstone 1 unit (Bp 1), conglomerate 2 unit (Kgl 2), and sandstone 2 unit (Bp 2) with their distribution and thickness are thinning to the top. Mineralization distribution in the eastern area, mainly on Kgl 1 unit, dominated by detritus materials from epi-genetic depositional in the form of monazite which is formed along with the formation of granite as its source rock. Meanwhile, mineralization on the upper rocks units formed a channel pattern trending northeast-southwest, which formed in syn-genetic process consist of uraninite, carnotite, and coffinite. Sibolga Formation deposition originated from east to west and uranium deposit formed because of the differences of depositional environment from oxidation in the east to the more reductive in the southwest. The increasing of organic materials in southwest basin caused the reduction condition of depositional environment. (author)

  6. Discussion on well field technology for acid in-situ leaching of uranium at a deposit of Yining uranium mine

    International Nuclear Information System (INIS)

    Ye Shandong; Wu Yunhui; Yin Guifang

    2005-01-01

    The characteristics of geology and hydrogeology of a uranium deposit, the make-up and use of lixiviant, equilibrium control of push-pull, improvement of air lift efficiency, layout of well net, and management of well construction are described. (authors)

  7. Use of paleogeochemical topographic maps for prediction of epigenetic uranium deposits

    International Nuclear Information System (INIS)

    Perel'man, A.I.

    1985-01-01

    The role of paleogeochemical maps for prospecting for and predicting uranium deposits is considered. The method of paleogeochemical landscape mapping is based on the landscape geochemistry, modern notions of geochemical condition evolution during geologic history, on the general principles of geochemical mapping. The use of the above-mentioned maps for predicting epigenetic uranium deposits is based on prospecting criteria and signs, which follow from epigenetic theory of the deposit genesis. According to the above theory a number of signs, favourable for the formation of deposits of this class (aride climate, granitoids and other rocks in the area of artesian water source, depression shapes of relief, etc.), is established

  8. Resource potential for commodities in addition to Uranium in sandstone-hosted deposits: Chapter 13

    Science.gov (United States)

    Breit, George N.

    2016-01-01

    Sandstone-hosted deposits mined primarily for their uranium content also have been a source of vanadium and modest amounts of copper. Processing of these ores has also recovered small amounts of molybdenum, rhenium, rare earth elements, scandium, and selenium. These deposits share a generally common origin, but variations in the source of metals, composition of ore-forming solutions, and geologic history result in complex variability in deposit composition. This heterogeneity is evident regionally within the same host rock, as well as within districts. Future recovery of elements associated with uranium in these deposits will be strongly dependent on mining and ore-processing methods.

  9. The discovery and character of Pleistocene calcrete uranium deposits in the Southern High Plains of west Texas, United States

    Science.gov (United States)

    Van Gosen, Bradley S.; Hall, Susan M.

    2017-12-18

    This report describes the discovery and geology of two near-surface uranium deposits within calcareous lacustrine strata of Pleistocene age in west Texas, United States. Calcrete uranium deposits have not been previously reported in the United States. The west Texas uranium deposits share characteristics with some calcrete uranium deposits in Western Australia—uranium-vanadium minerals hosted by nonpedogenic calcretes deposited in saline lacustrine environments.In the mid-1970s, Kerr-McGee Corporation conducted a regional uranium exploration program in the Southern High Plains province of the United States, which led to the discovery of two shallow uranium deposits (that were not publicly reported). With extensive drilling, Kerr-McGee delineated one deposit of about 2.1 million metric tons of ore with an average grade of 0.037 percent U3O8 and another deposit of about 0.93 million metric tons of ore averaging 0.047 percent U3O8.The west-Texas calcrete uranium-vanadium deposits occur in calcareous, fine-grained sediments interpreted to be deposited in saline lakes formed during dry interglacial periods of the Pleistocene. The lakes were associated with drainages upstream of a large Pleistocene lake. Age determinations of tephra in strata adjacent to one deposit indicate the host strata is middle Pleistocene in age.Examination of the uranium-vanadium mineralization by scanning-electron microscopy indicated at least two generations of uranium-vanadium deposition in the lacustrine strata identified as carnotite and a strontium-uranium-vanadium mineral. Preliminary uranium-series results indicate a two-component system in the host calcrete, with early lacustrine carbonate that was deposited (or recrystallized) about 190 kilo-annum, followed much later by carnotite-rich crusts and strontium-uranium-vanadium mineralization in the Holocene (about 5 kilo-annum). Differences in initial 234U/238U activity ratios indicate two separate, distinct fluid sources.

  10. Mid-crustal uranium and rare metal mineralisation in the Mount Isa Inlier: a genetic model for formation of orogenic uranium deposits

    OpenAIRE

    McGloin, Matthew

    2017-01-01

    Uranium mineralisation near Mount Isa in northwest Queensland, Australia, is widespread yet poorly understood. Within this region in the Western Fold Belt, one hundred and ninety uranium-rare metal occurrences are known. This uranium mineralisation is similar to worldwide examples of albitite-hosted or sodium-metasomatic uranium deposits, which host albite-carbonate ore zones enriched in incompatible elements. Various metal sources and ore-forming processes have been sugg...

  11. Uranium geology of Bulgaria

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Three major uranium districts containing several deposits, plus 32 additional deposits, have been identified in Bulgaria, all of which are detailed geologically in this article. Most of the deposits are located in the West Balkan mountains, the western Rhodope mountains, and the Thracian Basin. A few deposits occur in the East Balkan, eastern Rhodope and Sredna Gora mountains. The types of deposits are sandstone, vein, volcanic, and surficial. Sandstone deposits are hosted in Permian and Tertiary sediments. In early 1992, fifteen deposits were being exploited, of which roughly 70 percent of the uranium produced was being recovered using in-situ leaching (ISL) methods. The remainder was being recovered by conventional underground mining, except for one small deposit that utilized open-pit methods. Fifteen other Bulgarian deposits had been exhausted, while five deposits were still in the exploration stage. Uranium production began in Bulgaria in 1946, and cumulative production through 1991 exceeded 100 million pounds equivalent U3O8. Current annual production is on the order of one million pounds equivalent U3O8, about 750 thousand pounds of which are recovered by ISL operations

  12. Uranium Elemental and Isotopic Constraints on Groundwater Flow Beneath the Nopal I Uranium Deposit, Pena Blanca, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    S.J. Goldstein; M.T. Murrell; A.M. Simmons

    2005-07-11

    The Nopal I uranium deposit in Chihuahua, Mexico, is an excellent analogue for evaluating the fate of spent fuel, associated actinides, and fission products over long time scales for the proposed Yucca Mountain high-level nuclear waste repository. In 2003, three groundwater wells were drilled directly adjacent to (PB-1) and 50 m on either side of the uranium deposit (PB-2 and PB-3) in order to evaluate uranium-series transport in three dimensions. After drilling, uranium concentrations were elevated in all of the three wells (0.1-18 ppm) due to drilling activities and subsequently decreased to {approx}5-20% of initial values over the next several months. The {sup 234}U/{sup 238}U activity ratios were similar for PB-1 and PB-2 (1.005 to 1.079) but distinct for PB-3 (1.36 to 1.83) over this time period, suggesting limited mixing between groundwater from these wells over these short time and length scales. Regional groundwater wells located up to several km from the deposit also have distinct uranium isotopic characteristics and constrain mixing over larger length and time scales. We model the decreasing uranium concentrations in the newly drilled wells with a simple one-dimensional advection-dispersion model, assuming uranium is introduced as a slug to each of the wells and transported as a conservative tracer. Using this model for our data, the relative uranium concentrations are dependent on both the longitudinal dispersion as well as the mean groundwater flow velocity. These parameters have been found to be correlated in both laboratory and field studies of groundwater velocity and dispersion (Klotz et al., 1980). Using typical relationships between velocity and dispersion for field and laboratory studies along with the relationship observed from our uranium data, both velocity (1-10 n/yr) and dispersion coefficient (1E-5 to 1E-2 cm{sup 2}/s) can be derived from the modeling. As discussed above, these relatively small flow velocities and dispersivities agree with

  13. Aeromagnetic data analysis for the identification of concealed uranium deposits: A case history from Singhbhum uranium province, India

    Science.gov (United States)

    Anand, S. P.; Rajaram, M.

    2006-08-01

    Aeromagnetic data on a part of the Singhbhum uranium province, India, within the framework of `Operation Hard Rock' have been analyzed. The aeromagnetic anomaly map, its analytic signal amplitude, the Euler solutions and apparent susceptibility map helped in identifying the nature and depth of the magnetic sources in the study region. The Singhbhum Shear Zone is clearly delineated. The location of the mined uranium deposits coincide with the shallow magnetic sources. The present study also identified distinctive magnetic sources between the Dalma Volcanics and the Chotanagpur Granitic Gneissic Complex that suggest the presence of a sub-surface shear. The magnetic sources in this newly identified shear zone lie at a depth of 200 m and depict a similar magnetic signature and susceptibility as those of the Singhbhum Shear Zone where uranium is being mined. This shear could be the subsurface contact between high-grade metamorphic rocks (amphibolite facies) to the north and the greenschist facies low-grade metamorphics to the south. This shear zone, also characterized by radiometric anomalies, possibly indicates a zone of concealed uranium deposit that can be explored in the future. The present analysis shows the importance of aeromagnetic surveys and its utility in exploration for concealed mineral deposits.

  14. LA-ICPMS zircon U-Pb age of Maofeng pluton of uranium deposit No.337 and its significance

    International Nuclear Information System (INIS)

    Zhang Zhanshi; Hua Renmin; Yao Junmin; Gu Shengyan; Deng Ping; Wu Lieqin

    2007-01-01

    Maofeng pluton is the most important uranium-host granite in Xiazhuang uranium orefield. The accurate granite formation age and its evolution history is crucial for understanding the mineralization in this district. LA-ICPMS zircon dating was applied in this paper and found the formation age of Maofeng pluton is 238.2 ± 2.3 Ma which suggests that Maofeng pluton was produced in the Indosinian magmatic event. Uranium mineralization age of No.337 deposit is commonly recognized to be 138 Ma. Therefore No.337 uranium deposit was not the typical magma hydrothermal deposit due to the long time gap between the pluton formation and the uranium mineralization. (authors)

  15. Uranium from phosphates to rabbit bones: Predicting dietary contribution to uranium deposition in animal bones

    International Nuclear Information System (INIS)

    Canella Avelar, A.; Motta Ferreira, W.; Menezes, M.

    2014-01-01

    Uranium is a hazardous element, both for radioactivity and metallotoxicity. Health implications of human overexposure to uranium are well documented: from reproduction impairment, liver and kidney diseases to some types of cancer. There are limited data in the modern literature concerning the levels of uranium in animal tissues and foods, as well the dietary daily intake of uranium is not fully known both for man and livestock. On the other hand, practically every phosphate and its products contain uranium in its structure. The average U content in agricultural phosphate may vary from 10 up to 390 ppm. In this particular feature, uranium can reach animal and man food chain by ingestion of feed and food grade phosphate containing U.

  16. Epithermal uranium deposits in a volcanogenic context: the example of Nopal 1 deposit, Sierra de Pena Blanca, Mexico

    Science.gov (United States)

    Calas, G.; Angiboust, S.; Fayek, M.; Camacho, A.; Allard, T.; Agrinier, P.

    2009-12-01

    The Peña Blanca molybdenum-uranium field (Chihuahua, Mexico) exhibits over 100 airborne anomalies hosted in tertiary ignimbritic ash-flow tuffs (44 Ma) overlying the Pozos conglomerate and a sequence of Cretaceous carbonate rocks. Uranium occurrences are associated with breccia zones at the intersection of two or more fault systems. Periodic reactivation of these structures associated with Basin and Range and Rio Grande tectonic events resulted in the mobilization of U and other elements by meteoric fluids heated by geothermal activity. Trace element geochemistry (U, Th, REE) provides evidence for local mobilization of uranium under oxidizing conditions. In addition, O- and H-isotope geochemistry of kaolinite, smectite, opal and calcite suggests that argillic alteration proceeded at shallow depth with meteoric water at 25-75 °C. Focussed along breccia zones, fluids precipitated several generations of pyrite and uraninite together with kaolinite, as in the Nopal 1 mine, indicating that mineralization and hydrothermal alteration of volcanic tuffs are contemporaneous. Low δ34S values (~ -24.5 ‰) of pyrites intimately associated with uraninite suggest that the reducing conditions at the origin of the U-mineralization arise from biological activity. Later, the uplift of Sierra Pena Blanca resulted in oxidation and remobilization of uranium, as confirmed by the spatial distribution of radiation-induced defect centers in kaolinites. These data show that tectonism and biogenic reducing conditions can play a major role in the formation and remobilization of uranium in epithermal deposits. By comparison with the other uranium deposits at Sierra Pena Blanca and nearby Sierra de Gomez, Nopal 1 deposit is one of the few deposits having retained a reduced uranium mineralization.

  17. Uranium distribution in mined deposits and in the earth's crust. Final report

    International Nuclear Information System (INIS)

    Deffeyes, K.; MacGregor, I.

    1978-08-01

    Examination of both the global distribution of uranium in various geological units and the distribution of uranium ore grades mined in the U.S. shows that both distributions can be described by a single lognormal curve. The slope of that distribution indicates approximately a 300-fold increase in the amount of uranium contained for each 10-fold decrease in ore grade. Dividing up the U.S. production by depth zones, by geologic setting, by mineralogical types, by geographic regions, and by deposit thicknesses shows substantially the same 300-fold increase in contained uranium for each 10-fold decrease in ore grade. Lieberman's (1976) analysis of uranium discoveries as an exponentially declining function of the feet of borehole drilled was extended. The analysis, in current dollars and also in constant-value dollars, using exploration expenditures and acreage leases as well as drilling effort, shows that a wide range of estimates results. The conclusion suggests that the total uranium available in the 300 to 800 part-per-million range will expand through byproduct and coproduct mining of uranium, through increased exploitation of low-grade ores in known areas, and through the exploration of terrains which historically never produced high-grade ores. These sources of uranium (coupled with efficient reactors like the heavy-water reactors) could postpone the economic need for mining 100 part-per-million deposits, and the need for the breeder reactor and fuel reprocessing, well into the next century

  18. Catahoula formation of the Texas coastal plain: origin, geochemical evolution, and characteristics of uranium deposits

    International Nuclear Information System (INIS)

    Galloway, W.E.; Kaiser, W.R.

    1979-01-01

    Uranium was released from volcanic glass deposited within the Catahoula through early pedogenic and diagenetic processes. Pedogenesis was the most efficient process for mobilizing uranium. Original uranium content in fresh Catahoula glass is estimated to have averaged at least 10 ppM; about 5 ppM was mobilized after deposition and made available for migration. Uranium was transported predominantly as uranyl dicarbonate ion. Chlorinity mapping reveals modern ground-water flow patterns. Six utranium deposits representative of the ores were studied. Uranium-bearing meteoric waters were reduced by pre-ore stage pyrite formed by extrinsically introduced fault-leaked sulfide or intrinsically by organic matter. Uranium was concentrated in part by adsorption on Ca-montmorillonite cutans, amorphous TiO 2 , and/or organic matter followed by uranyl reduction to U 4+ in amorphous uranous silicates. Clinoptilolite is not correlative with mineralization. Calcite is pervasive throughout host sands but shows no relationship to uranium mineralization. Presence of marcasite and uranium together at the alteration front strongly supports an acid pH during Catahoula mineralization. Maximum adsorption and minimum solubility of uranium occur at pH 6 in carbonate-rich waters. Log activity ratios of individual waters supersaturated with respect to montmorillonite, taken from montmorillonite-clinoptilolite activity diagrams, show positive correlation with uranium mineralization. High Ca 2+ , Mg 2+ , Al(OH) 4 - , and H + activities promote the formation of montmorillonite relative to clinoptilolite. High saturation ratios for montmorillonite show fair correlation with mineralization. The mineral-solution equilibria approach is a potential method of geochemical exploration. 56 figures, 8 tables

  19. Some concepts of favorability for world-class-type uranium deposits in the northeastern United States

    Energy Technology Data Exchange (ETDEWEB)

    Adler, H.H.

    1981-03-01

    An account is given of concepts of favorability of geologic environments in the eastern United States for uranium deposits of several major types existing elsewhere in the world. The purpose is to convey some initial ideas about the interrelationships of the geology of the eastern United States and the geologic settings of certain of these world-class deposits. The study and report include consideration of uranium deposits other than those generally manifesting the geologic, geochemical and genetic characteristics associated with the conventional sandstone-type ores of the western United States.

  20. Some concepts of favorability for world-class-type uranium deposits in the northeastern United States

    International Nuclear Information System (INIS)

    Adler, H.H.

    1981-03-01

    An account is given of concepts of favorability of geologic environments in the eastern United States for uranium deposits of several major types existing elsewhere in the world. The purpose is to convey some initial ideas about the interrelationships of the geology of the eastern United States and the geologic settings of certain of these world-class deposits. The study and report include consideration of uranium deposits other than those generally manifesting the geologic, geochemical and genetic characteristics associated with the conventional sandstone-type ores of the western United States

  1. THE EXPLOITATION OF THE TULGHEŞ-GRINŢIEŞ URANIUM DEPOSIT. BETWEEN BENEFITS AND CONTROVERSY

    OpenAIRE

    G. B. TOFAN; A. NIŢĂ; C. NIMARĂ; B. N. PĂCURAR

    2016-01-01

    The Exploitation of the Tulgheș-Grințieș Uranium Deposit. Between Benefits and Controversy. Romania is one of the few European states (alongside the Czech Republic, France, Germany, Ukraine) and one of the few in the world with uranium deposits (Canada, Australia, Niger, Namibia are others), mainly used in the energy sector. According to recent studies, the only currently exploited deposit (Crucea-Botușana, Suceava County) is nearly depleted (by 2019) and will be eventually shut down. For thi...

  2. Two main types of uranium deposit within phanerozoic formations of Ukraine

    International Nuclear Information System (INIS)

    Shumlyanskiy, V.A.

    1997-01-01

    The two main types of uranium deposits occurring within Phanaerozoic formations of Ukraine are described. They consist of uraniferous bearing bitumen in the Upper Carboniferous to Lower Triassic red beds, and infiltration (roll front type) uranium ores, occurring in the sediments filling ancient Paleogene river valleys. The first deposit type include black to dark brown beds of disseminated to massive bitumen occurring respectively as ozyantraxolite and oxykerite. These beds include uranium, as well as other metals. This uranium mineralization is dated at 195 to 200 million years old. The second type includes infiltration deposits in Paleogene coal bearing sediments, with the uranium mineralization occurring in the upper part of the sequence. The sediments occur within paleovallyes eroded into the underlying crystalline basement of the Ukraine shield and its weathered crust. The paleovalleys extend to a depth of 70 to 90 metres. The coal bearing sediments are overlain by sediments of younger age. Several uranium deposits of the second type are known, including a few identified as being of industrial grade. (author). 7 figs

  3. Paleo-channel type uranium deposits in western Siberia and Transbaikal regions

    International Nuclear Information System (INIS)

    Shor, G.M.; Markov, S.N.; Rubinov, I.M.; Peshkov, P.A.

    2002-01-01

    The author systematically introduces the geologic background, characteristics of uranium mineralization and uranium metallogenic conditions of the three regions in Russia (Transural, western Siberia and Transbaikal regions) where important paleo-channel type uranium deposits have been discovered. Authors propose that those paleo-channel type uranium deposits that incise the basement may occur both in the periphery of trans-regional orogenic belt and activated young platform or ancient shield, may be formed both under arid and humid climate conditions. The ore-formation process of mineralization begins from the deposition of ore-hosting sediments and continues until the ore-hosting horizon is covered by impermeable clay or basalt layer. There are two types of paleo-channel epigenetic oxidation zonation: oxidation zone-uranium mineralized zone-primary grey sandstone; oxidation zone-zone of iron oxide reprecipitation-zone of bleached rocks-primary grey sandstone. Ores of paleo-channel type uranium deposits are enriched in a wide spectrum of associated elements which is related to the abundant content of organic matters in ore-hosting sandstone and the existence of various geochemical barriers at the pinch out sites of oxidation zone

  4. Gastric cancer in New Mexico counties with significant deposits of uranium

    International Nuclear Information System (INIS)

    Wilkinson, G.S.

    1985-01-01

    Several counties in northern New Mexico display high rates of mortality from gastric cancer. Significant differences in sex-specific, age-adjusted, average annual stomach cancer mortality rates among whites from 1970-1979 were found between counties with significant deposits of uranium compared to those without significant deposits. These results remained unchanged when either socioeconomic status or Hispanic ethnicity were considered. Additional research needs to consider individual characteristics and competing risk factors for individuals with gastric cancer in these counties. A working hypothesis is that residents of counties with significant deposits of uranium are exposed to higher-than-average environmental levels of radionuclides such as radon and radon daughters, or to trace elements such as arsenic, cadmium, selenium, and lead which are commonly found in areas with uranium deposits

  5. Geochemical feature of stable isotopes in sandstone-type uranium deposit 511 in Xinjiang, China

    International Nuclear Information System (INIS)

    Zeng Aihua; Pan Jiayong

    2013-01-01

    Uranium deposit 511 is a typical in-situ leachable sandstone-type uranium deposit, study on its geochemical characteristics of stable isotopes may give help to the exploration and mining design of other deposit of the same kind. Considering the geology feature of uranium deposit 511, we analyzed its geochemical features of stable isotopes S, C, H and O by using EA-MS, MAT-253, GAS-Bench and GASBENCH-MAT253 facilities. The experimental results indicated that S has close relationship with the process of sulfate changing into sulphide through reducing bacteria, C may come organic carbon, the relative low and negative value of C, H and O isotopes suggest that the metallogenic fluid were originated from atmospheric precipitation. (authors)

  6. Summary of investigations of uranium deposits in the Pumpkin Buttes area, Johnson and Campbell Counties, Wyoming

    Science.gov (United States)

    Troyer, Max L.; McKay, Edward J.; Soister, Paul E.; Wallace, Stewart R.

    1954-01-01

    Uranium minerals were discovered in the Pumpkin Buttes area, Campbell and Johnson Counties, Wyo., by the U. S. Geological Survey in October 1951. From June to November 1952, an area of about 750 square miles was examined for uranium deposits, and 211 localities having abnormally high radioactivity were found; uranium minerals are visible at 121 of these localities. All known uranium mineralization in the area is restricted to sandstones of the Wasatch formation, except sparsely disseminated uranium in the sandstone of the White River formation, which caps the Pumpkin Buttes, mid several localities on the Great Pine Ridge southwest of the Pumpkin Buttes where iron-saturated sandstone and clinker in the Fort Union formation have above-normal radioactivity. The uranium occurrences in the Wasatch formation are in a red sandstone zone 450 to 900 feet above the base of the formation and are of two types: small concretionary masses of uranium, iron, manganese and vanadium minerals in sandstone, and irregular zones in which uranium minerals are disseminated in sandstone. The second type is usually larger but of lower grade than the first. Most of the localities at which uranium occurs are in a north-trending belt about 60 miles long and 18 miles in maximum width.

  7. Mortimer Hills pegmatite uranium prospect: a Rossing-type uranium deposit in the Gascoyne Province

    International Nuclear Information System (INIS)

    Carter, J.D.

    1984-01-01

    A uraninite-bearing pegmatite of large dimensions in the Gascoyne Province is described. The pegmatite is compared with the Rossing uranium ore body of South West Africa and the two are shown to have common characteristics. Exploration recommendations for Rossing-type uranium mineralization in the Gascoyne Province are made

  8. Extraction of uranium from seawater with magnesium hydroxide precipitate depositing from seawater

    International Nuclear Information System (INIS)

    Fujinaga, Taitiro; Kuwamoto, Tooru; Nakayama, Eiichiro; Isshiki, Kenji

    1984-01-01

    Magnesium hydroxide precipitate depositing from alkalized seawater was used as an adsorbent for the extraction of uranium from seawater. Calcium hydroxide was a suitable alkali because the adsorption of uranium was enhanced in the presence of calcium ion. Uranium was adsorbed quantitatively with magnesium hydroxide precipitate when an adequate amount of calcium hydroxide was added to precipitate 80 to 90 % of magnesium ion in seawater. More than 80 % of adsorbed uranium was eluted from the precipitate with 1 to 3 M ammonium carbonate solution, in which the precipitate was hardly dissolved at all. With this method about 11 mg of uranium was collected as uranyl salt from 6,000 l of natural seawater. The recovery throughout all processes was about 70 % (author)

  9. Origin of uranium and rare earth minerals in bone detritus from rare metal deposits

    Science.gov (United States)

    Baturin, G. N.; Dubinchuk, V. T.

    2011-06-01

    In order to ascertain the forms in which uranium is present in ores of the Melovoe rare metal sedimentary deposit of uranium and rare earth minerals (South Mangyshlak), we investigated a series of typical ore samples that were collected earlier; both the uranium content and the total content of rare earth metals in them lay within 0.1-0.3%. The study was carried out by analytical electron microscopy using transmission electron microscopy and scanning electron microscopy, electron microdiffraction, and microprobing. It was ascertained that both uranium and rare earth elements are present in ore mostly associated with biogenic phosphate in the form of natural minerals, such as uraninite, ningyoite, coffinite, autenite, and churchite. Iron hydroxides and graphitized organic matter are present in some samples. It is assumed that the co-occurrence of uranium and rare earth elements, which is nontypical for the sedimentary process, resulted from secondary epigenetic processes and alternation of reducing and oxidizing environmental conditions.

  10. Insight of the distribution and general characters of uranium deposits in the world (except France)

    International Nuclear Information System (INIS)

    Gangloff, A.

    1956-01-01

    It gives a large insight of uranium deposits and general characters of uranium deposits on the planet (except France). It gives a review of the mineralized area of the main uranium producers country with a geographic and geologic recall. Moreover, it brings together all the important prospecting results from countries which have presented a report at the international conference on the pacific uses of atomic energy in geneva (8-20 august 1955). All these countries are cited except France. It described not only the payable deposits as each deposit brings interesting indications for future prospecting and might also become payable in the future. It started with the geological survey of USA and Canada and the geographic description of their different uranium deposit sites as both country present the largest uranium resources. In the same way, geographic and geological surveys of South Africa, Democratic Republic of Congo, Australia, India, Brazil, Argentina, Rhodesia, Mozambia, Sweden, Norway, United kingdom, Portugal, Yugoslavia, Italy, Austria and Switzerland are described. (M.P.)

  11. THE EXPLOITATION OF THE TULGHEŞ-GRINŢIEŞ URANIUM DEPOSIT. BETWEEN BENEFITS AND CONTROVERSY

    Directory of Open Access Journals (Sweden)

    G. B. TOFAN

    2016-06-01

    Full Text Available The Exploitation of the Tulgheș-Grințieș Uranium Deposit. Between Benefits and Controversy. Romania is one of the few European states (alongside the Czech Republic, France, Germany, Ukraine and one of the few in the world with uranium deposits (Canada, Australia, Niger, Namibia are others, mainly used in the energy sector. According to recent studies, the only currently exploited deposit (Crucea-Botușana, Suceava County is nearly depleted (by 2019 and will be eventually shut down. For this reason, there are plans to open a new uranium mining facility in the Tulgheș-Grințieș area, where geological surveys have proven that the area holds the largest uranium deposit in the country. It will provide the necessary fuel for Cernavodă Nuclear Power Plant, for the two functional reactors, which have a total capacity of 706 MW each (producing roughly 18% of the country's electricity needs, as well as for units 3 and 4, not operational yet. The study at hand intends to emphasize several aspects regarding the exploitation possibilities for the uranium deposit from the two mineralized structures located in the fracture areas of the central Carpathian line, through which the crystalline overflows the Cretaceous Flysch. Furthermore, the environmental impact analysis as well as the long term safety and security of the population inhabiting the area will be of utmost importance.

  12. Sandstone uranium deposits of Eurasia – from genetic concepts to forecasting and new discoveries

    International Nuclear Information System (INIS)

    Pechenkin, I.

    2014-01-01

    Along the Eurasian continent’s southern borders lie uranium ore provinces and regions controlling medium-sized and, on rare occasions, large sandstone deposits. Central French, Eastern Rhodope and other regions are known in the west. Large uranium ore provinces were discovered in the south of the Turan Plate and in the depressions of South Kazakhstan, viz. Central Kyzyl Kum, Syr Darya, Chu Sarysu. A common criterion has been established for all objects of the sandstone type, located in oil and gas, coal etc. sedimentary basins – the zone of interlayer or ground-interlayer oxidation, controlling uranium mineralization. In 2003 we were able to justify the concept that the formation of giant deposits in Chu Sarysu province was caused by the collision between the Indian Plate and the southern part of the Eurasian continent. Within the limits of Pacific ore belt there is a zonal distribution of ore deposits. Ordinary mineralization is drawn towards its eastern fringe: gold, tin, copper, tungsten etc. Volcanic and tectonic structures of central type of Mesozoic age are located further west, from the north to the south, that is large calderas – Streltsovskaya (Russia), Dornot (Mongolia), Sian Shan (China), which control large and unique endogene uranium deposits. In the far west, in the region of subsiding tectonic tensions, there are sandstone deposits of uranium in Transbaikalia, Mongolia and Yunnan, which are specially connected to young basalts. Infiltration deposits of Vitim region are adjacent to endogene deposits of Streltsovsky region in the southern-easterly direction, and to the east of the deposits of Yunnan at the same latitude lay the Sian Shan caldera with geothermal deposits of uranium and other metals. We combined them into the unified submeridional Baikal-Southern China uranium ore belt. After examining the southern extremities of the Eurasian continent, the region of the collision of the Indian Plate, a distinct similarity can be perceived between

  13. Uranium-series dating of some lake and dune deposits in south-east Australia

    International Nuclear Information System (INIS)

    Herczeg, A.L.

    1987-01-01

    A correction scheme developed over many years was used to obtain reliable dates for impure carbonates and gypsum from uranium disequilibrium analyses. The materials analyzed thus far and their sources are described. The results indicated that reliable dating can be obtained provided that there is no post-depositional alteration in the sample and that sufficient uranium is present. The object is to investigate further sites in order to reconstruct palaeohydrology and environments in Australia over the last 400000 years. 4 refs

  14. Uranium deposits in connection with the tertiary vulcanities of the Latin American Cordilleras

    International Nuclear Information System (INIS)

    Michel, H.; Schneider, H.J.

    1978-01-01

    During the last ten years, uranium deposits of a rather unknown and unnoticed type till now have been discovered in the Latin American Cordilleras. The uranium is concentrated in tertiary, acid vulcanites (mostly ignimbrites) and the adjacent clastic sedimentary series. Occurences of this type have become known from Mexico via Bolivia to Argentinia and owing to the enormous spreading of the vulcanities certainly represent reserves of economical interest. (orig.) 891 HP/orig. 892 MKO [de

  15. Staging of surveys of small uranium deposits in Bohemian Massif crystalline formation

    International Nuclear Information System (INIS)

    Vesely, T.

    1981-01-01

    The projecting and implementation of uranium prospecting is divided into seven stages. Research work consists of subject research and of prognostic estimation. Surveying work is implemented in the stage of preparatory prospecting, the stage of evaluation prospecting and the stage of detailed prospecting. The survey work proper consists of preliminary and detailed survey stages. The scope of the individual stages is described and the application is outlined of the respective stages in surveying small uranium deposits. (J.B.)

  16. Natural analogue study on Tono sandstone-type uranium deposit in Japan

    International Nuclear Information System (INIS)

    Seo, T.; Ochiai, Y.; Takeda, S.; Nakatsuka, N.

    1989-01-01

    The Tertiary Tono sandstone-type uranium deposit is recognized as a potentially useful analogue for the geological isolation of radioactive wastes in Japan. The study of this natural analogue is being carried out to acquire information about the geochemical processes that relate to the containment and migration of uranium series nuclides over geologic time. There is no significant migration for uranium for the samples investigated as the result of radioactive disequilibrium study. The hydrogeochemical study suggests that the groundwater in the ore horizons is very stagnant and reducing

  17. Sandstone uranium deposits in the United States: a review of the history, distribution, genesis, mining areas, and outlook

    International Nuclear Information System (INIS)

    Crawley, R.A.

    1983-03-01

    Sandstone uranium deposits account for about 94 percent of uranium reserves in the United States. Most sandstone uranium districts had been found by the mid-1950s in response to incentives promulgated by the US Atomic Energy Commission. Principal uranium resource regions in the United States are the Colorado Plateau, Wyoming Basins, and Texas Coastal Plain. Statistical data published annually by the US Department of Energy show trends of uranium exploration and production, estimates of resources, and distributions and characteristics of reserves. At present, US exploration and production are curtailed because of uranium oversupply, a trend that will continue for the next few years. Although the outlook is more optimistic over the longer term, it is clouded by possible competition from foreign low-cost, nonsandstone uranium. Roll-type and peneconcordant are the two principal types of sandstone uranium deposits. Roll deposits are formed at geochemical fronts where oxidizing uranium-bearing groundwater penetrates reduced sandstone. Uranium is precipitated by reduction at the front. Under mildly reducing conditions, uranium may remain in solution until it is locally precipitated by reduction, chelation, or complexing to form peneconcordant deposits. Proposed precipitating agents include carbonaceous matter, humate, pyrite, and hydrogen sulfide. The uranium is thought to have been derived from leaching of tuffaceous or arkosic sediments, or of granitic rocks

  18. U-Pb dating of uranium deposits in collapse breccia pipes of the Grand Canyon region

    Science.gov (United States)

    Ludwig, K. R.; Simmons, K.R.

    1992-01-01

    Two major periods of uranium mineralization are indicated by U-Pb isotope dating of uranium ores from collapse breccia pipes in the Grand Canyon region, northern Arizona. The Hack 2 and 3, Kanab North, and EZ 1 and 2 orebodies apparently formed in the interval of 200 ?? 20 Ma, similar to ages inferred for strata-bound, Late Triassic-hosted uranium deposits in southern Utah and northern Arizona. Samples from the Grand Canyon and Pine Nut pipes, however, indicate a distinctly older age of about 260 Ma. The clustering in ages for a variety of uranium deposits at about the age of the lower part of the Chinle Formation (Late Triassic) suggests that uranium in these deposits may have been derived by leaching from volcanic ash in the Chinle and mobilized by ground-water movement. Pb isotope ratios of galenas in mineralized pipes are more radiogenic than those of sulfides from either uranium-poor pipes or occurrences away from pipes. Fluids which passed through the pipes had interacted with the Proterozoic basement, possibly through the vertical fractures which influenced the location and evolution of the pipes themselves. -from Authors

  19. New exploration results of the Elkon uranium district deposits and prospects for their development

    International Nuclear Information System (INIS)

    Danilov, A.; Krasnykh, S.; Zhuravlev, V.; Kuzmin, E.; Tarkhanov, A.

    2014-01-01

    The Elkon Uranium District (EUD) is located in the Republic of Sakha (Yakutia) and is of strategic importance for the Russian uranium industry. It comprises more than 40% of the entire Russian uranium mineral resource and 4% of the world's uranium resources. Drilling and underground mining completed in 1961-1986 amounted to over 600,000 m and 52,500 m, respectively. The performed activities resulted in the discovery of the Yuzhnaya Zone and the Severnoe deposits. The Yuzhnaya Zone uranium resources (Measured + Indicated + Inferred) amounted to 257.8 kt (grade 0.146%). Uranium mineralisation contains 141 t of gold, 1784 t of silver and 41,5 kt of molybdenum. The Severnoe Inferred resources have been estimated at 58.6 kt (grade 0.149%). During the period of 2007-2011 over 100,000 m of drilling and associated activities was completed within the Yuzhnaya Zone and Severnoe deposits along with optimisation of ore mining and processing methods, and geological and economic revaluation of the deposits.

  20. Geology of uranium vein deposits (including Schwartzwalder Mine) in Proterozoic metamorphic rocks, Front Range, Colorado

    International Nuclear Information System (INIS)

    Voto, R.H. de; Paschis, J.A.

    1980-01-01

    The Schwartzwalder uranium deposit is one of many uranium vein occurrences in the Lower Proterozoic metamorphic rocks of the Front Range, Colorado. The principal veins of significant uranium content occur marginal to the Colorado Mineral Belt; are localized by structural dilation zones, vein junctions, fault deflections or branching; and occur dominantly within or at the contact of certain preferred metamorphic-stratigraphic units, particularly the siliceous, garnetiferous gneisses, where these rock units are broken by faults and fractures associated with the north-northwest-trending throughgoing faults. Uranium at the Schwartzwalder mine occurs primarily as open-space brecciated vein filling along the steeply west-dipping Illinois vein and numerous east-dipping subsidiary veins where they cut preferred metamorphic host rocks that are tightly folded. Uraninite occurs with molybdenite, adularia, jordisite, ankerite, pyrite, base-metal sulphides, and calcite in vein-filling paragenetic sequence. Minor wall-rock alteration is mainly hematite alteration and bleaching. Vertical relief on the developed ore deposit is 900 metres and still open-ended at depth. No vertical zonation of alteration, vein mineralogy, density of the subsidiary veins, or ore grade has been detected. The Schwartzwalder uranium deposit is of substantial tonnage (greater than 10,000 metric tons of U 3 O 8 ) and grade (averaging 0.57% U 3 O 8 ). Structural mapping shows that the Illinois vein-fault is a Proterozoic structure. Discordant Proterozoic (suggested) and Laramide dates have been obtained from Schwartzwalder ore. The data suggest, therefore, a Proterozoic ancestry of this heretofore presumed Laramide (Late Cretaceous-Early Tertiary) hydrothermal uranium deposit. The authors suggest a polygenetic model for the origin of the Schwartzwalder uranium deposit

  1. Uranium minerals and radioactive equilibrium in the Jordan phosphate deposit of Ruseifa

    International Nuclear Information System (INIS)

    Zereini, F.; Urban, H.

    1989-01-01

    In the open pit of Ruseifa (Jordan) a marine sedimentary succession is mined, which belongs to the Maastrichian stage (Upper Cretacious). This up to 28 m thick succession is composed of an alternated stratification of phosphorites, limestones, clay marls and cherts with gradations between these main rock types. As all these rocks contain apatite in varying amounts the whole succession is designed by the term 'phoshate layer'. In the 'phosphate layer' 4 workable phosphorite bearing beds with thicknesses between 1.15 and 3.45 m are present, giving an eminent economical importance to the deposit. Especially the stratigraphically youngest, the fourth phosphorite bed, shows remarkably increased gamma-activities. In the phoshorite the average uranium content amounts up to 110 ppm U. The mineral apatite has been identified to be the main carrier of the uranium. In veins and fissures yellow secondary uranium minerals occur, which have been determined as carnotite and metatuyamunite. The discovery, that uranium is in a state of preponderant radioactive equilibrium with its daughter products, is important for the genesis of the uranium enrichments as well as for practical means of mining. The detected radioactive disequilibria are restricted to the formation of secondary uranium minerals on fissures and joints demonstrating distinct migration of uranium and its daughter product in the last 800 000 years (quaternary until recent weathering). These young geochemical weathering processes did not essentially change the syngenetic distribution of uranium in the phosphorite. With the determined mean uranium content of 110 ppm the whole uranium reserves of Ruseifa evaluates approximately 8580 t of uranium metal out of total phosphate reserves of 78 mio. t. (orig.) [de

  2. The metallogenic model of sandstone-type uranium deposits in interlayer oxidation zone in Yili basin

    International Nuclear Information System (INIS)

    Chen Daisheng; Wang Ruiying; Li Shengxiang; Zhang Kefang

    1997-08-01

    On the basis of comprehensive analysis on various sedimentary environmental criteria, the authors establish a depositional facies model of wet fan formed by alluvial fan's fast pouring into lake for the ore-bearing rocks, and point out favourable horizons and facies for the formation of uranium mineralizations. Deep researches are also done to uranium mineralization characteristics in interlayer oxidation zone, zonation features of ore bodies and spatial distribution regularities of uranium mineralizations. Three sets of data on ore-formation ages (19 Ma, 12 Ma, 1.0 Ma) are obtained with U-Pb isotope method. Various ore-controlling factors of the sandstone-type uranium mineralizations are expounded in detail. Ore-formation mechanism and metallogenic model of sandstone-type uranium deposit in the basin are summarized. Finally, the authors propose some detailed suggestions for the delimitation of prospective areas and future work in the basin, and emphasize that the southwest margin of the basin, especially the area between deposit No.511 and deposit No.512 should be a key prospecting area in the future. (4 refs., 6 figs., 3 tabs.)

  3. Uranium deposits obtention for fission chambers; Obtencion de depositos de uranio para fabricacion de camaras de fision

    Energy Technology Data Exchange (ETDEWEB)

    Artacho Saviron, E.

    1972-07-01

    The obtention of uranium deposits of the required quality for small cylindrical fission chambers presents some difficulties. With the method of electroplating here described the uniformity, reproducibility and adherence of the obtained deposits were satisfactory. (Author) 6 refs.

  4. Geological and geochemical aspects of uranium deposits: a selected, annotated bibliography. Vol. 2, Rev. 1

    International Nuclear Information System (INIS)

    Thomas, J.M.; Brock, M.L.; Garland, P.A.; White, M.B.; Daniel, E.W.

    1979-07-01

    This bibliography, a compilation of 490 references, is the second in a series compiled from the National Uranium Resource Evaluation (NURE) Bibliographic Data Base. This data base is one of six data bases created by the Ecological Sciences Information Center, Oak Ridge National Laboratory, for the Grand Junction Office of the Department of Energy. Major emphasis for this volume has been placed on uranium geology, encompassing deposition, genesis of ore deposits, and ore controls; and prospecting techniques, including geochemistry and aerial reconnaissance. The following indexes are provided to aid the user in locating references of interest: author, geographic location, quadrangle name, geoformational feature, taxonomic name, and keyword

  5. Geological and geochemical aspects of uranium deposits: a selected, annotated bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J.M.; Brock, M.L.; Garland, P.A.; White, M.B.; Daniel, E.W. (comps.)

    1978-06-01

    A compilation of 490 references is presented which is the second in a series compiled from the National Uranium Resource Evaluation (NURE) Bibliographic Data Base. This data base is one of six created by the Ecological Sciences Information Center, Oak Ridge National Laboratory, for the Grand Junction Office of the Department of Energy. Major emphasis for this volume has been placed on uranium geology, encompassing deposition, genesis of ore deposits, and ore controls; and prospecting techniques, including geochemistry and aerial reconnaissance. The following indexes are provided to aid the user in locating references of interest: author, geographic location, quadrangel name, geoformational feature, taxonomic name, and keyword.

  6. Geological and geochemical aspects of uranium deposits: a selected, annotated bibliography

    International Nuclear Information System (INIS)

    Thomas, J.M.; Brock, M.L.; Garland, P.A.; White, M.B.; Daniel, E.W.

    1978-06-01

    A compilation of 490 references is presented which is the second in a series compiled from the National Uranium Resource Evaluation (NURE) Bibliographic Data Base. This data base is one of six created by the Ecological Sciences Information Center, Oak Ridge National Laboratory, for the Grand Junction Office of the Department of Energy. Major emphasis for this volume has been placed on uranium geology, encompassing deposition, genesis of ore deposits, and ore controls; and prospecting techniques, including geochemistry and aerial reconnaissance. The following indexes are provided to aid the user in locating references of interest: author, geographic location, quadrangel name, geoformational feature, taxonomic name, and keyword

  7. Geology and uranium deposits of the Cochetopa and Marshall Pass districts, Saguache and Gunnison counties, Colorado

    Science.gov (United States)

    Olson, Jerry C.

    1988-01-01

    The Cochetopa and Marshall Pass uranium districts are in Saguache and Gunnison Counties, south-central Colorado. Geologic mapping of both districts has shown that their structural history and geologic relationships have a bearing on the distribution and origin of their uranium deposits. In both districts, the principal uranium deposits are situated at the intersection of major faults with Tertiary erosion surfaces. These surfaces were buried by early Tertiary siliceous tuffs-- a likely source of the uranium. That uranium deposits are related to such unconformities in various parts of the world has been suggested by many other authors. The purpose of this study is to understand the geology of the two districts and to define a genetic model for uranium deposits that may be useful in the discovery and evaluation of uranium deposits in these and other similar geologic settings. The Cochetopa and Marshall Pass uranium districts produced nearly 1,200 metric tons of uranium oxide from 1956 to 1963. Several workings at the Los Ochos mine in the Cochetopa district, and the Pitch mine in the Marshall Pass district, accounted for about 97 percent of this production, but numerous other occurrences of uranium are known in the two districts. As a result of exploration of the Pitch deposit in the 1970's, a large open-pit mining operation began in 1978. Proterozoic rocks in both districts comprise metavolcanic, metasedimentary, and igneous units. Granitic rocks, predominantly quartz monzonitic in composition, occupy large areas. In the northwestern part of the Cochetopa district, metavolcanic and related metasedimentary rocks are of low grade (lower amphibolite facies). In the Marshall Pass district, layered metamorphic rocks are predominantly metasedimentary and are of higher (sillimanite subfacies) grade than the Cochetopa rocks. Paleozoic sedimentary rocks in the Marshall Pass district range from Late Cambrian to Pennsylvanian in age and are 700 m thick. The Paleozoic rocks

  8. Geology of uranium deposits in the southern part of the Rocky Mountain province of Colorado

    International Nuclear Information System (INIS)

    Malan, R.C.

    1983-07-01

    This report summarizes the geology of uranium deposits in the southern part of the Rocky Mountains of Colorado, an area of about 20,000 square miles. In January 1966, combined ore reserves and ore production at 28 uranium deposits were about 685,000 tons of ore averaging 0.24 percent U 3 O 8 (3.32 million pounds U 3 O 8 ). About half of these deposits each contain <1,000 tons of ore. The two largest deposits, the Pitch in the Marshall Pass locality southwest of Salida and the T-1 in the Cochetopa locality southeast of Gunnison, account for about 90 percent of all production and available reserves. The probability in excellent for major expansion of reserves in Marshall Pass and is favorable at a few other vein localities. There are six types of uranium deposits, and there were at least four ages of emplacement of these deposits in the southern part of the Colorado Rockies. There are eight types of host rocks of eight different ages. Veins and stratiform deposits each account for about 40 percent of the total number of deposits, but the veins of early and middle Tertiary age account for nearly all of the total reserves plus production. The remaining 20 percent of the deposits include uraniferous pegmatites, irregular disseminations in porphyry, and other less important types. The wall rocks at the large Tertiary vein deposits in the southern part of the Rocky Mountains of Colorado are Paleozoic and Mesozoic sedimentary rocks, whereas Precambrian metamorphic wall rocks predominate at the large veins in the Front Range of the northern Colorado Rockies. Metallogenetic considerations and tectonic influences affecting the distribution of uranium in Colorado and in adjacent portions of the western United States are analyzed

  9. Contribution to the geochemical knowledge of the uranium-radium and thorium families in the southern Vosges. Applications of some results in the prospecting of uranium deposits

    International Nuclear Information System (INIS)

    Jurain, G.

    1962-01-01

    This work's aim is to lead to a more accurate knowledge of the geochemistry of the Uranium-Radium and Thorium families in the Southern Vosges and to apply some of the results to the prospecting of uraniferous deposits: It has been showed: a bond between Calcium-Magnesium and Uranium-Thorium in the calco-alkaline granites. The host minerals of Uranium and Thorium are hornblende, biotite, titanite and epidote. a concentration of Uranium, at present time with secular disequilibrium in a thermal zone where the satellite mineralizations form an epithermal paragenesis. a disequilibrium of the Uranium-Radium family in the supergene minerals of the lead (phosphate and vanadate) showing the present circulations of Uranium. a bond between the radon grade of the spring waters and Uranium-Radium of the rocks. Such a relation allow to realize a prospecting method based on the determination of radioactive gases from the cold spring-waters of a common country. (author) [fr

  10. Carbonaceous matters in epigenetic uranium deposits associated with zones of layer oxidation

    International Nuclear Information System (INIS)

    Shchetochkin, V.N.; Uspensij, V.A.; Solntseva, L.C.

    1975-01-01

    The paper presents investigations on the carbonaceous substances encountered in uranium deposits of a certain type. A set of methods (IR spectroscopy, ultimate analysis and others) was used to examine the various types of carbonaceous compounds, their composition, structure and geochemistry, and their role in the formation of uranium concentrations. All the carbonaceous substances are divided into two main groups according to their spacial distribution: those syngenetic to the ore-containing sediments; and epigenetic materials introduced into them as a result of the development of an ascending carbon-bitumen process. A considerable similarity was found between the compositions and properties of forms that are known to have no genetic relation to each other, while carbonaceous formations related by a common origin and belonging to the same group are represented by several modifications with different internal structures and compositons. All the carbonaceous compounds of the syngenetic group occur in a random relationships to the uranium mineralization. Nevertheless, the presence of syngenetic carbonaceous substances assists the formation of rich concentrations of uranium. The appearance of epigenetic carbonaceous substances (bitumens) is generally more closely spacially related to zones of development of uranium mineralization. The maximum concentrations of uranium are typical for hard insoluble bitumens. Among the soluble bitumens, the carbonaceous substances - bitumen S - bound in epigenetic materials, are most enriched in uranium (up to px10 -3 %). The role of the bitumens differs in the formation of displaced and primary uranium ores. In the first case, the significance of the bitumens, seems to lie in the reduction of the redox potential of the infiltrated uranium-bearing waters. In the second case, it is possible that a co-migration of uranium and certain types of carbonaceous substance (bitumen S, hard bitumen) took place in reducing (by iron) solutions

  11. The Crownpoint and Churchrock uranium deposits, San Juan Basin, New Mexico: An ISL mining perspective

    International Nuclear Information System (INIS)

    McCarn, D.W.

    2001-01-01

    The Crownpoint and Churchrock uranium deposits, San Juan Basin, New Mexico are currently being developed by Uranium Resources, Inc. (URI) and its subsidiary Hydro Resources, Inc. (HRI) with an anticipated start-up in 1998. Both deposits will be developed using advanced in situ leach (ISL) mining techniques. URI/HRI currently has about 14,583 t U (37.834 million pounds U 3 O 8 ) of estimated recoverable reserves at Crownpoint and Churchrock. at a cost less than $39/kg U ($15/lb U 3 O 8 ). The uranium endowment of the San Juan Basin is the largest of any province in the USA. In March, 1997, a Final Environmental Impact Statement (FEIS) for the Crownpoint and Churchrock sites was completed by the Nuclear Regulatory Commission which recommends the issuance of an operating license. The FEIS is the culmination of a 9 year effort to license and develop the deposits. The Westwater Canyon Member of the Jurassic Morrison Formation is an arkosic, fine to coarse grained sandstone bounded by near basinwide confining clays deposited in a wet alluvial fan environment within the San Juan Basin. The primary, trend-ore deposits are hosted by the Westwater Canyon Member as humate-rich, syngenetic tabular deposits which were subsequently remobilized into roll fronts. Since deposition in the Jurassic, two phases of remobilization have occurred in the basin causing the formation of in situ leach amenable monometallic uranium rolls free of organic debris. Following in situ mining, ground water restoration of the Crownpoint and Churchrock mines is required to provide a water quality consistent with pre-mining baseline conditions. The development of in situ mining offers an environmentally sound and cost-effective method for uranium extraction. URI/HRI anticipates a production of 385-1,156 Tonnes U/year (1-3 million pounds U 3 O 8 ) from the New Mexico properties. (author)

  12. Tianmujian caldera. A potential area for locating rich and large uranium deposit

    International Nuclear Information System (INIS)

    Lin Ziyu; Xu Jinshan; Chen Mingzhuo; Jiang Jinyuan; Fan Honghai; Cheng Qi

    2001-01-01

    Based on the comprehensive analysis on geologic, remote sensing, gravimetric, magnetic and geochemical data, and the field geologic investigation, the author has preliminarily ascertained the formation and the distribution characteristics of the Tianmujian caldera, and recognized the porphyroclastic lava system which is extensively distributed in the area. The authors suggest that the Tianmujian volcanic basin experienced two evolution stages--the thermal uplifting and the formation of caldera, that large concealed uranium-rich granitic massif occurs in the area, and during the vertical evolution process the uranium showed its concentration in the lower part and depletion in the upper part, and large amount of ore-forming material moved upward along with the magmatic hydrothermals entering the caldera to form uranium deposit. In addition, it is clarified that the NE-NW rhombic-formed basement structural pattern is predominated by the NE-trending fault. At the same time, the important role of the basement faults in controlling the magmatic activities, in the formation of volcanic basins, as well as the formation of uranium mineralization is emphasized. On the basis of the above comprehensive analysis the authors suggest that the Tianmujian caldera is a quite favourable potential area for possessing the basic conditions necessary for the formation of rich and large uranium deposit including uranium 'source, migration, concentration, preservation' and favourable multiple metallogenic information is displayed in the Tianmujian area

  13. Rock magnetic investigation and its geological significance for vein-type uranium deposits in southern China

    Science.gov (United States)

    Ge, Kunpeng; Liu, Qingsong; Deng, Juzhi; Nobes, David; Wang, Yang; Wang, Yanguo; Chen, Xiao

    2017-04-01

    To characterize the metallogenic environment of a typical vein-type uranium deposit, samples from diabase dykes, alteration zones including metamorphic diabase and uranium ore, and granites were systematically investigated for six boreholes from southeastern China. Rock magnetic results indicate that coarse-grained magnetites (pseudosingle domain, PSD, and multidomain, MD) are dominant magnetic carriers in diabase. In contrast, the uranium ore is dominated by fine-grained magnetites (superparamagnetic, SP, and single-domain, SD). The concentration of magnetic particles in fresh granites is low. Magnetic properties of metamorphic diabases exhibit much greater variability of magnetic properties and higher degrees of sulfuration than unaltered diabase and granite, due to contact metasomatism and reduction effects close to the vein. Compared with diabase, magnetic remanence of the uranium ore is much lower, but displays much higher stability. The Koenigsberger ratio Q peaks in the uranium ore with a value of ˜1.00. Using the systematic rock magnetic results to constrain the interpretation, the contribution of the intersection zone of diabase dyke and silicified fault to magnetic anomalies was further modeled, and the effects of the ore body are significant for magnetic exploration. Overall, rock magnetic investigations of vein-type uranium deposit provide a better understanding of the interactions between different rock types, and further facilitate regional magnetic surveys on the ground.

  14. Study of rare earth elements, uranium and thorium migration in rocks from Espinharas uranium deposit, Paraiba - Brazil

    International Nuclear Information System (INIS)

    Conceicao, Cirilo C.S.

    2009-01-01

    The determination of rare earth elements as natural analogue in patterns geologic has grown as a tool for predicting the long-term safety of nuclear disposal in geological formation. Migration of natural radionuclides is one of the most serious problems in the waste deposit from nuclear fuel cycle. Rare earth elements show the same kinetic behavior in rocks as natural radionuclides. This similar property of the analogues allows perform studies and models on the subject of radionuclides migration. The aim of this study was to determine the distribution of rare earth elements in rocks located at Espinharas - Paraiba - Brazil, uranium deposit. In this work are presented the results from the study above the distribution of rare earth elements in function of the degree of mineralized rocks, composition and the conditions of radioactive equilibrium of the uranium and thorium in some fractures on the rocks from radioactive occurrence of Espinharas-Brazil. The results show that there is a correlation of heavy rare earth elements, uranium and Thorium concentrations to oxidation factor of the rocks. However this correlation was not observed for light rare earth elements. It means that heavy rare earth elements follow the natural radionuclides in oxidation process of rocks. The samples were analyzed by ICP-MS, alpha and gamma spectrometry, X-ray diffraction and fluorimetry. (author)

  15. Uranium

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Developments in the the uranium industry in Australia that took place during the quarter ended 30 June 1980 are reviewed. These include uranium mine production and uranium exploration. Prices for uranium oxide and uranium hexafluoride as at the end of June 1980 and figures for U 3 O 8 production and export from 1978 to March 1980 are listed

  16. A study of U-Pb isotopic evolutionary system in Chanziping uranium deposit

    International Nuclear Information System (INIS)

    Xu Weichang; Huang Shijie; Xia Yuliang.

    1988-01-01

    Chanziping uranium deposit occurred in the black siliceous slate of Lower cambrian. The uranium mineralization was controlled by both interstratified fault belt and the ore-bearing beds. Based on the study of the U-Pb isotopic system of the various rocks, ores and minerals in the ore-bearing beds, the authors find out the obvious disequilibrium of U-Pb isotopic composition in most rock samples which indicates the loss of uranium form the ore-bearing beds and surrounding granite. Its counting loss ranges from 30 to 80%. The age of rich ores of the U-Pb concordance diagram and the U-Pb three stage model are t 1 = 523 ± 19M. Y. , t 2 = 22 ± 2 M.Y.. The isochronal ages for pitchblend are 75 ± 4 M.Y., 43 ± 7 M.Y., and for rock is 416 M.y.. These data shows that the uranium in ore-bearing beds was mainly derived from the ore-bearing beds itself and partly from the surrounding granite. The ore deposit can be considered to be of stratabound uranium deposit of sedimentation and late transformation type

  17. Catahoula formation as a source of sedimentary uranium deposits in east Texas

    International Nuclear Information System (INIS)

    Ledger, E.B.; Tieh, T.T.

    1983-01-01

    Volcanic glass-rich mudstone and siltstone samples from the Oligocene/Miocene Catahoula formation of Jasper County, Texas, and coeval volcaniclastic rock samples from Trans-Pecos, Texas, have been compared as to U, Th, Zr, Ti, K, Rb, and Sr contents. Uranium is slightly greater in the distal ash (5.85 ppM U) compared to the Trans-Pecos samples (average 5.41 ppM U). Diagenetic and pedogenetic alteration of Catahoula volcanic glass releases uranium to solution and, under favorable conditions, this uranium may accumulate to form ore bodies. Uranium has been produced from such ore bodies in south Texas, but economic deposits are not known in east Texas. Significant differences between south and east Texas include: (1) a greater amount of volcanic debris delivered to south Texas, both as air-fall ash and stream-transported material, (2) delivery of only air-fill ash to east Texas, (3) the possibility of more petroleum-related reductants such as H 2 S in south Texas, and (4) pervasive glass alteration with subsequent uranium release in south Texas due to late calichification. These differences argue against economic deposits of the south Texas type being found in east Texas. If economic deposits occur they are likely to be far downdip making exploration difficult and expensive

  18. Determination of 36Cl in the groundwaters and ores around a uranium deposit

    Science.gov (United States)

    Jiang, Songsheng; Jiang, Shan; Guo, Hong; Du, Shubin; Chen, Zhanru; Guo, Qifeng; Zhao, Yunlong

    1994-06-01

    We intend to use fission-induced 36Cl as a tracer to study the transport of mobile radionuclides and the invasion of a uranium ore body by groundwater in Lianshanguan uranium deposit, which has been considered as a natural geochemical analogue for a nuclear waste repository. The ore and groundwater samples were selected around the uranium deposit. The measurement of 36Cl was carried out using accelerator mass spectrometry at the China Institute of Atomic Energy. After correction for native Cl in the samples, the deduced 36Cl/Cl ratios range from 7000 × 10 -15 to 15000 × 10 -15 for ore samples and from 1200 × 10 -15 to 150 × 10 -15 for groundwater samples. The calculated 36Cl contents range from 3.7 × 10 7 to 7.5 × 10 6 atoms/g in the ore samples and from 1.4 × 10 8 to 8.2 × 10 6 atoms/1 in the groundwater samples. The calculated concentration of cosmogenic 36Cl in the groundwater is 5 × 10 6 atoms. The result shows that the concentration of 36Cl in groundwater is mainly due to in-situ production of 36Cl leached from the ore body by the groundwater and the 36Cl tracer can be used to investigate the invasion of the uranium ore body by groundwater and the geochemical isolation of groundwater in the uranium deposit area.

  19. Preparation of uranium coatings by electro deposition in molten chloride media

    International Nuclear Information System (INIS)

    Taxil, P.; Serrano, K.; Dugne, O.

    2001-01-01

    The electrodeposition of uranium is now a relevant topic for two kinds of applications: the preparation of this metal with compounds extracted from the mineral ores; the separation from lanthanides in the nuclear waste. This paper concerns the process of preparation of uranium metal on various substrates, using the electro deposition process in molten salts. The electrolyte consists of an eutectic mixture NaCl-KCl as solvent (fusion point 650 deg C) and a tetravalent uranium compound, UCl 4 as solute. We present the results, theoretical and practical, necessary to manage the process. So, the following points will be considered stepwise in this paper: the electrochemical behaviour of uranium III ions in the electrolyte, since it is now clearly established that uranium metal can be prepared by electrochemical reduction of UCl 3 in a NaCl-KCl mixture in a single step process: U III + 3 e → U 0 ; the crystallisation mode of uranium on the cathodic material; the preparation of uranium coatings with variables conditions: temperature, electrolyte concentration, current density and cathodic substrate; the observation of the crystal growth on the substrates, by using SEM micrographies. (authors)

  20. A discussion of remote sensing geologic image model of a uranium deposit

    International Nuclear Information System (INIS)

    Qiao Rui

    1998-12-01

    Based on the geologic study on the uranium deposit, the items about remote sensing images of the mineral deposit were discussed, such as the best choice of temporal, the best compose of band, the image characteristics and image model. It is considered that the mineral deposit was controlled by the line, ring and arc through the interpretation of color-composite images. The geologic image model of the mineral deposit is annular fault block controlled by northeast and northwest structures. It is recommended that much attentions should be paid to mineralized regions being similar with this image model in long-range forecast

  1. On the classification of uranium deposits associated with volcano-techtonic depressions

    International Nuclear Information System (INIS)

    Konstantinov, V.M.

    1981-01-01

    Advisability of separating uranium deposits associated with volcano-techtonic depressions as a class is grounded. Three groups of deposits are stated: foundation or low depression zone, medium depression zone, upper depression zone. Deposits are unified in five subgroups: in terrigenic molass, effusion- sedimentary formations, paleovulcanic setups and subvulcanic intrusions, granitoides, sedimentary and metamorphical rocks of geocinclinic complex. 18 structural-morphological types of deposits are determined by accounting of the basic structural-lithologic factors of ore control. An idealized diagram of ore-bearing vulcano-techtonic depression and its alternations at different erosion shears are presented. A conclusion is made on practical application of the classification [ru

  2. The Kvanefjeld rare earth and uranium deposits in the llimaussaq alkaline complex (Greenland)

    International Nuclear Information System (INIS)

    Lagny, Ph.

    2012-01-01

    Presentation of the Kvanefjeld deposit in Greenland, a new rare earth deposit that will be in production in a near future, and which is included in the llimaussaq alkaline complex located at the southern end of Greenland. Apart from the fact that it contains considerable amounts of rare earths and uranium, the main interest of this deposit is that its ore includes a relatively high part of heavy rare earths which are particularly searched for by a large number of industrial applications. The geology of the deposit is detailed and commented

  3. Application of gas geochemistry experiment in the search for different types of uranium deposits

    International Nuclear Information System (INIS)

    Chen Guoliang; Liu Hanbin; Dong Xiukang; Xiong Xianxiang; Li Zhenfu; Wu Duanyang

    1998-03-01

    The study of primary and secondary gas halo and their application in the search for different types of uranium deposits in China is presented. Through measuring Rn, CO 2 , O 2 and Hg in various deposits of geological and climatic conditions for the gas geochemical survey, three comprehensive measuring methods of CO 2 , Rn and O 2 were thought to be optimum for gas geochemical exploration because of its portability, rapidity, low cost, simple operation and limited interference. The experimental data can be briefly summarized that higher concentration of CO 2 , Rn and lower concentration of secondary halo in soil show blinded deposits. The study of thermal emanating gas in soil and rock have been finished. The methods were confirmed by known deposits and can be used in uranium exploration

  4. A economic evaluation system software on in-situ leaching mining sandstone uranium deposits

    International Nuclear Information System (INIS)

    Yao Yixuan; Su Xuebin; Xie Weixing; Que Weimin

    2001-01-01

    The author presents the study results of applying computer technology to evaluate quantitatively the technical-economic feasibility of in-situ leaching mining sandstone uranium deposits. A computer system software have been developed. Under specifying deposit conditions and given production size per year, the application of the software will generate total capital and mine life operating costs as well as solve for the movable and static financial assessment targets through discounted cash flow analysis. According to the characters of two kinds of sandstone uranium deposits, a data bases of economic and technique parameters of in-situ leaching have been designed. Also the system software can be used to study the economic value of deposits and to optimize the key project parameters. Its features, data input method and demand, main functions, structure and operating environments are described

  5. Cogema's world-wide experience in prospecting and surveying uranium deposits

    International Nuclear Information System (INIS)

    Berville, M.; Faure, D.

    1985-01-01

    Having briefly outlined the history of uranium prospection in France, the authors describe COGEMA's prospection operations at home and abroad and analyse the methods applied according to different contexts (granitic and metamorphic rocks, ''sub-discordant'' deposits, sedimentary deposits, prospection in detail of a qualified zone); at the same time they show how technology has developed, particularly in the fields of geophysics and radiometry [fr

  6. Uniform deposition of uranium hexafluoride (UF6): Standardized mass deposits and controlled isotopic ratios using a thermal fluorination method.

    Science.gov (United States)

    McNamara, Bruce K; O'Hara, Matthew J; Casella, Andrew M; Carter, Jennifer C; Addleman, R Shane; MacFarlan, Paul J

    2016-07-01

    We report a convenient method for the generation of volatile uranium hexafluoride (UF6) from solid uranium oxides and other U compounds, followed by uniform deposition of low levels of UF6 onto sampling coupons. Under laminar flow conditions, UF6 is shown to interact with surfaces within a fixed reactor geometry to a highly predictable degree. We demonstrate the preparation of U deposits that range between approximately 0.01 and 500ngcm(-2). The data suggest the method can be extended to creating depositions at the sub-picogramcm(-2) level. The isotopic composition of the deposits can be customized by selection of the U source materials and we demonstrate a layering technique whereby two U solids, each with a different isotopic composition, are employed to form successive layers of UF6 on a surface. The result is an ultra-thin deposit that bears an isotopic signature that is a composite of the two U sources. The reported deposition method has direct application to the development of unique analytical standards for nuclear safeguards and forensics. Further, the method allows access to very low atomic or molecular coverages of surfaces. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Hydrochemical uranium mining at the Straz ore deposit and its hydrogeological consequences

    International Nuclear Information System (INIS)

    Hanzlik, J.; Moravec, J.; Macak, P.

    1992-01-01

    The uranium ore deposit at Straz is situated in the North Bohemian Cretaceous Massif. Uranium is extracted from the deposit by underground chemical leaching by means of drills from the ground. Relevant to this kind of extraction, from the hydrogeological and environmental aspects, are the hydrogeological location of the deposit, the kind and amounts of the leaching solution and ways of its injection. The following amounts, in thousand tons, have been injected underground throughout the entire period of practicing chemical extraction of uranium (till 1990): sulfuric acid 3700, nitric acid 270, ammonia 100, hydrofluoric acid 25. The overall area of the leaching fields is 630 hectares, which accommodate 9300 technological boreholes. The environmental burden of the Cenomanian rocks and Turonian water reservoir was analyzed, and significantly elevated heavy metal contents from the recirculation of the technological solutions were found. The solutions expand beyond the leaching fields, causing a contamination of underground water within wider surroundings. The volume of contaminated water in the Turonian reservoir is currently estimated at 2 - 20 million m 3 . Uranium extraction by leaching is harmful at this deposit, having far-reaching impacts on the hydrosphere and ecosystem (increased dust, deforestation of slopes of the Ralsko hill, contamination of water and soil, etc.). Abandoning the ore extraction appears to be the sole feasible approach to this problem. (Z.S.). 2 tabs., 3 figs

  8. Uranium solution mining cost estimating technique: means for rapid comparative analysis of deposits

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    Twelve graphs provide a technique for determining relative cost ranges for uranium solution mining projects. The use of the technique can provide a consistent framework for rapid comparative analysis of various properties of mining situations. The technique is also useful to determine the sensitivities of cost figures to incremental changes in mining factors or deposit characteristics

  9. Geostatistical ore reserve estimation for a roll-front type uranium deposit (practitioner's guide)

    International Nuclear Information System (INIS)

    Kim, Y.C.; Knudsen, H.P.

    1977-01-01

    This report comprises two parts. Part I contains illustrative examples of each phase of a geostatistical study using a roll-front type uranium deposit. Part II contains five computer programs and comprehensive users' manuals for these programs which are necessary to make a practical geostatistical study

  10. Exploration of Bernabe Montano complex of uranium deposits, New Mexico, USA

    International Nuclear Information System (INIS)

    Porter, D.A.

    1981-01-01

    The Bernabe Montano discovery is a significant eastern extension of the Grants Mineral Belt, consisting of two nearly parallel mineralized trends with a combined strike length of about 14.5 km. One deposit with approximately 10 6 lb of uranium oxide has been blocked out and several km of mineralized trend require additional delineation drilling. The mineralization exhibits many similarities to Westwater Canyon Member ore deposits in other parts of the Grants Mineral Belt; one of the most significant is the continuation of the south-easterly trend that has persisted, with some breaks, for a length of over 175 km. As with other Grants Mineral Belt deposits, the mineralization is associated with multilevel humate masses that are roughly parallel to the bedding of the Westwater Canyon Member host sandstone beds. These humate masses and the associated uranium deposits show a marked preference for the margins of the thicker, more laterally continuous, channelways. The discovery of the Bernabe Montano complex of deposits is significant for several reasons. First, it opened up exploration in the distal fan facies where many geologists thought the uranium potential was relatively low. The discovery is potentially more significant in that it demonstrates the ability of detailed subsurface geologic mapping to suggest the location of high potential geologic trends in partially explored but favourable regions where the more traditional surface geologic and radiometric techniques are no longer effective in finding new deposits. (author)

  11. The computerized semi-quantitative comprehensive identification-evaluation model for the large-sized in-situ leachable sandstone type uranium deposits in Northern Xinjiang, China

    International Nuclear Information System (INIS)

    Wang Zhengbang; Qin Mingkuan; Zhao Ruiquan; Tang Shenghuang; Wang Baoqun; Lin Shuangxing

    2001-01-01

    The process of establishment of the model includes following steps: (1) Systematically studying a known typical in-situ leachable sandstone type uranium deposit--Deposit No. 512 in Yili basin, analyzing its controlling factors and establishing its metallogenetic model; (2) Establishing the metallogenetic models of this type of uranium deposit and uranium-bearing area on the basis of comparison study on the deposit No. 512 with the same type uranium deposits in the world; (3) Creating the computerized semi-quantitative comprehensive identification-evaluation model for the large-sized in-situ leachable sandstone type uranium deposits in northern Xinjiang; (4) Determining the standards of giving a evaluation-mark for each controlling factor of in-situ leachable sandstone type uranium deposit and uranium-bearing area; (5) Evaluating uranium potential and prospect of the unknown objective target

  12. Characteristics and significance of uranium bearing pan african younger granite in the eastern desert, Egypt

    International Nuclear Information System (INIS)

    Hassan, M.A.; Dabbour, G.A.; Mohammden, T.F.

    1998-01-01

    Surficial uranium mineralization was discovered in four pan african younger granite plutons in the eastern desert of egypt. The present study revealed great similarity between these plutons both in petrography and geochemistry. They are two-feldspar, two-mica peraluminous granites which have been formed by melting of crustal materials and emplaced during the late stage stage of a late proterozoic orogenic cycle. Radiometric and geochemical investigations indicate that these granites are fertile with respect to U and form a potential target for primary uranium deposits. Four models are suggested to explain the source and mechanism of the surficial uranium mineralization in these granites. The most applicable model is the oxidation of U +4 found in minute disseminated uraninite grains and its subsequent mobilization. This is supported by petrographic and autoradiographic studies. The bearings of the present study on further exploration for uranium deposits in granites of the arabian- Nubian shield in general are discussed

  13. Uranium deposits in the Eureka Gulch area, Central City district, Gilpin County, Colorado

    Science.gov (United States)

    Sims, P.K.; Osterwald, F.W.; Tooker, E.W.

    1954-01-01

    The Eureka Gulch area of the Central City district, Gilpin County, Colo., was mined for ores of gold, silver, copper, lead, and zinc; but there has been little mining activity in the area since World War I. Between 1951 and 1953 nine radioactive mine dumps were discovered in the area by the U.S. Geological Survey and by prospectors. the importance of the discoveries has not been determined as all but one of the mines are inaccessible, but the distribution, quantity, and grade of the radioactive materials found on the mine dumps indicate that the area is worth of additional exploration as a possible source of uranium ore. The uranium ans other metals are in and near steeply dipping mesothermal veins of Laramide age intrusive rocks. Pitchblende is present in at least four veins, and metatorbernite, associated at places with kosolite, is found along two veins for a linear distance of about 700 feet. The pitchblends and metatorbernite appear to be mutually exclusive and seem to occur in different veins. Colloform grains of pitchblende were deposited in the vein essentially contemporaneously with pyrite. The pitchblende is earlier in the sequence of deposition than galena and sphalerite. The metatorbernite replaces altered biotite-quartz-plagioclase gneiss and altered amphibolite, and to a lesser extent forms coatings on fractures in these rocks adjacent to the veins; the kasolite fills vugs in highly altered material and in altered wall rocks. Much of the pitchblende found on the dumps has been partly leached subsequent to mining and is out of equilibrium. Selected samples of metatorbernite-bearing rock from one mine dump contain as much as 6.11 percent uranium. The pitchblende is a primary vein mineral deposited from uranium-bearing hydrothermal solutions. The metatorbernite probably formed by oxidation, solution, and transportation of uranium from primary pitchblende, but it may be a primary mineral deposited directly from fluids of different composition from these

  14. Ore controlling oxidized zonation epigenetic uranium-coal deposits and regularities in lignite transformations

    International Nuclear Information System (INIS)

    Uspenskij, V.A.; Kulakova, Ya.M.

    1982-01-01

    Complex of analytical methods was used to study epigenetic transformations in uranium-coal ore manifestation. To clarify the principle scheme of oxidized zonation in coals the materials, related to three similar objects were used. When comparing obtained epigenetic column with columns of similar ore objects the principle scheme of oxidized epigenetic zonation for ancient infiltration uranium-coal deposits was specified; general regularities of eignite transformations and characteristics of profile distribution of uranium and accessory metal zonations were revealed. Infiltration processes, proceeded in coal measureses, formed the steady epigenetic oxidized zonation: O - zone of barren unoxidized coals, 1 - zone of ore-bearing unoxidized coals, 2 - zone of weakly ore-bearing oxidized coals, 3 - zone of oxidized terrigenous rocks with zonules of development of yellow and red iron hydroxides. Capacities of some zones and zonules reflect the intensity and duration of ore-forming processes. Distribution of U and accessory elements obeys completely epigenetic zonation. It is assumed, that ancient infiltration uranium-coal deposits formed due to weakly uranium-bearing oxygen-containing waters

  15. Radioactivity of phosphates and the exploration of uranium at phosphate deposits of Iran

    International Nuclear Information System (INIS)

    Espihbod, M.R.

    1981-01-01

    The low grade uranium content usually not exceeding 150 p.p.m considered as an average, permitted the scientists to extract the uranium from sulfuric acid as by product. Therefore, in countries rich in phosphate deposits besides their consuming in petrochemical industries they could elaborate to extract the uranium far and wide when the refinery installations are designed for super phosphate and sulfuric acid fabrications. The objective of this article is strictly devoted to the sedimentary phosphatic deposits in the world. For this reason Iran entitled relatively as a rich country, possessing the large sedimentary phosphatic horizons in Eocene and uppermost cretaceous periods and also in a well distributed vicinities of Zagros range as well as central Alborz ''Jeirood formation'' of Devonian age together with western Alborz of Infracambrian age (this latter has been recently discovered by geological survey of Iran) has totally persuaded Atomic Energy Organization of Iran (A.E.O.I.) to pay attention on Uranium Prospection in large scale by studying continuously the phosphatic horizons and hopefully to exploit the uranium thereof. (author)

  16. The sedimentology and mineralogy of the river uranium deposit near Phuthaditjhaba, Qwa-Qwa

    International Nuclear Information System (INIS)

    Brynard, H.J.; Le Roux, J.P.

    1982-08-01

    A sedimentological and mineralogical investigation was carried out on the River deposit discovered by Mining Corporation (Pty) Ltd in Qwa-Qwa, 15 km south-west of Phuthaditjhaba. The orebody is located in fluvial sandstones of the upper Elliot Formation. Palaeocurrent directions reflect a low- to very low-sinuosity river system with a vector mean azimuth towards 062 degrees. A study of sedimentary structures and grain sizes in cliff sections was supplemented by an analysis of borehole logs, which disclosed the sedimentary environment as a braided river of the Donjek type. Uranium mineralisation at the River prospect is unusually thick, averaging almost 2 m, but lower overall grade than the southern Karoo deposits. Almost 30% of the uranium is present in mudstone and siltstone, and the fact that mineralisation in the sandstone is of similar grade and thickness to that of the former two lithological types suggests that grain sizes played a minor role in the dispersion of the ore fluids. The rocks are mainly of three types, viz. lithic graaywackes, feldspathic graywackes and siltstones, of which calcareous and carbonaceous varieties of the former two occur. Uranium mineralisation is associated mainly with organic carbon which occurs in various modes. A small amount of uranium is present as secondary beta-uranophane which occurs interstitially to detrital grains and in the pores of the clayey matrix and lithic fragments. Uranium is the only trace element of economic significance

  17. New production technology implementation to more efficiently and economically development of new uranium deposits

    International Nuclear Information System (INIS)

    Perkov, P.

    2005-01-01

    Full text: Uranium industry of Ukraine is based on the large reserves of uranium ores. Only reasonably assured resources are capable to meet more than centenarian needs of Ukrainian NPPs for natural uranium. Ukraine has all the capabilities to supply the whole domestic needs for natural uranium as well as produce it for export. To achieve this aim, in addition to two mines being under operation, it is necessary to put into operation the mine at the largest uranium deposit and a mine at one of the explored deposits. The following conclusions flow from evaluating the source of uranium raw materials in Ukraine as a whole: 1. The base of the source of uranium raw materials in Ukraine is formed by large deposits of relatively low-grade uranium ores of metasomatic type in the alkaline rock in the central part of the Ukrainian Crystalline Shield. The deposits of the second geological industrial type are ones of sandstone type. 2. When uranium content in the ores is lower than the one in the main producing countries' uranium deposits, those ores are remarkable for several properties which allow maintaining competitiveness of the uranium concentrate produced. Those properties concerning deposits of metasomatic type include such as: large extension of uranium beds; high strength properties of the ore and host rock; low water inflow; favourable radiological properties determining the capability of deep radiometric concentration; monometallic pattern of the ore stipulating the use of ore processing flow-sheet being simple enough and output of uranium concentrate of very high quality; the deposits are located at the well-handled areas with developed traffic network, arranged power supply systems, favourable climate, high supply of human resources; uranium deposits being located in the centre of Europe, near the main consumers. 3. The deposits of sandstone type are featured by small extension of the ore beds, small depth of occurrence, isolation of productive aquifer, favourable

  18. Redox buffer capacity of sedimentary rocks around uranium deposit. Study of water-mineral-microbe system at the Tono uranium deposit, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Iwatsuki, Teruki; Murakami, Yuki; Hama, Katsuhiro [Japan Nuclear Cycle Development Inst., Toki, Gifu (Japan). Tono Geoscience Center; Naganuma, Takeshi [Hiroshima Univ., Higashi-Hiroshima, Hiroshima (Japan). School of Biosphere Sciences

    2003-06-01

    The redox buffer capacity of the water-mineral-microbe system in and around the Tono uranium deposit, Japan, was studied to evaluate the long-term stability of the redox system. The uranium deposit occurs in the lower part of a Miocene sedimentary rock sequence that unconformably overlies granite. In the groundwater, profiles of redox sensitive solutes such as sulphate and sulphide ions, abundance and viability of microbes, and sulphur isotope ratios of sulphate ions suggest that microbial sulphate reduction involving organic matter and subsequent pyrite precipitation are dominant redox reactions at the depths of the uranium ore bodies. Concentrations of both the sulphate and chloride increase with increasing depth. The dissolved sulphate is surmised to have originated from dissolution of sulphate and sulphide minerals in a geologic marine formation precipitated in marine environments, in the upper part of the sedimentary rocks. Such a redox process in the water-mineral-microbe system is inferred to have continued from the time when the marine formation underwent uplift above sea-level, because sulphate-reducing bacteria can use sulphate ions dissolved in fresh water that infiltrates from the marine formation and organic matter located in the deeper sedimentary rocks. The chloride ion also has a linear relationship with groundwater residence time. from the relationship between sulphate and chloride ion concentrations, the sulphate ion dissolution rates from the marine formation are estimated at about 5.9 x 10{sup -5} mM/yr. Calculations by using the sulphate-S contents of the rocks and the sulphate dissolution rate suggest that microbial sulphate reduction alone could maintain sufficiently reducing conditions to preserve the uranium ore for several hundred thousand years, in the case where a hydrogeological system continues to exist without much change. (author)

  19. Redox buffer capacity of sedimentary rocks around uranium deposit. Study of water-mineral-microbe system at the Tono uranium deposit, Japan

    International Nuclear Information System (INIS)

    Iwatsuki, Teruki; Murakami, Yuki; Hama, Katsuhiro; Naganuma, Takeshi

    2003-01-01

    The redox buffer capacity of the water-mineral-microbe system in and around the Tono uranium deposit, Japan, was studied to evaluate the long-term stability of the redox system. The uranium deposit occurs in the lower part of a Miocene sedimentary rock sequence that unconformably overlies granite. In the groundwater, profiles of redox sensitive solutes such as sulphate and sulphide ions, abundance and viability of microbes, and sulphur isotope ratios of sulphate ions suggest that microbial sulphate reduction involving organic matter and subsequent pyrite precipitation are dominant redox reactions at the depths of the uranium ore bodies. Concentrations of both the sulphate and chloride increase with increasing depth. The dissolved sulphate is surmised to have originated from dissolution of sulphate and sulphide minerals in a geologic marine formation precipitated in marine environments, in the upper part of the sedimentary rocks. Such a redox process in the water-mineral-microbe system is inferred to have continued from the time when the marine formation underwent uplift above sea-level, because sulphate-reducing bacteria can use sulphate ions dissolved in fresh water that infiltrates from the marine formation and organic matter located in the deeper sedimentary rocks. The chloride ion also has a linear relationship with groundwater residence time. from the relationship between sulphate and chloride ion concentrations, the sulphate ion dissolution rates from the marine formation are estimated at about 5.9 x 10 -5 mM/yr. Calculations by using the sulphate-S contents of the rocks and the sulphate dissolution rate suggest that microbial sulphate reduction alone could maintain sufficiently reducing conditions to preserve the uranium ore for several hundred thousand years, in the case where a hydrogeological system continues to exist without much change. (author)

  20. Depositional environments of the uranium bearing Cutler Formations, Lisbon Valley, Utah

    International Nuclear Information System (INIS)

    Campbell, J.A.; Steele-Mallory, B.A.

    1979-01-01

    The Cutler Formation in Lisbon Valley, San Juan County, Utah, is composed predominantly of fluvial arkosic sandstones, siltstones, shales, and mudstones that were deposited by meandering streams that flowed across a flood plain and tidal flat close to sea level. Two types of channel deposits are recognized from their sedimentary structures: meandering and distributary. The flood plain was occasionally transgressed by a shallow sea from the west, resulting in the deposition of several thin limestones and marine sandstones. The marine sandstones were deposited as longshore bars. Wind transported sand along the shoreline of the shallow sea, forming a coastal dune field. Marine sandstones and eolian sandstones are more common in the upper Cutler in the southern part of the area, whereas in the central and northern part of the area the formation is predominantly fluvial. Crossbed orientation indicates that Cutler streams flowed S. 67 0 W. on the average, whereas marine currents moved sediment S. 36 0 E. and N. 24 0 W., and wind transported sand S. 80 0 E. The uranium in the Cutler is found in the central and northern part of the area, in the upper part of the formation, in small fluvial sandstone bodies that were deposited predominantly in a distributary environment. No uranium is known in the marine or eolian sandstones. Petrographically, the uranium-bearing sandstones are identical to other Cutler fluvial sandstones except that they contain less calcite and more clay and are slightly coarser grained. Ore formation has modified the host sandstones very little

  1. Remote sensing technology prospecting methods of interlayer oxidation zone type sandstone uranium deposit in Yili basin

    International Nuclear Information System (INIS)

    Huang Xianfang; Huang Shutao; Pan Wei; Feng Jie; Liu Dechang; Zhang Jingbo; Xuan Yanxiu; Rui Benshan

    1998-12-01

    Taking Yili Basin as an example, remote sensing technology and method of interlayer oxidation zone type sandstone uranium deposit have systematically been summarized. Firstly, principle, methods and procedures of the second development of scientific experimental satellite photograph have been elaborated in detail. Three dimensional stereo simulation, display, and multi-parameters extraction have been recommended. Secondarily, the research is focused on prospective section image features in different type images and their geological implications and on establishing recognition keys of promising areas. Finally, based on above research results, three graded predictions, i.e. regional prospect, promising sections and favourable location in the deposit have been made step by step and reconnaissance and prospecting range are gradually reduced. The practice has indicated that breakthrough progress has been made in application to prospect prognosis of interlayer oxidation zone type sandstone uranium deposit and good verified results have been obtained

  2. Study on metallogenetic prospect of interlayer oxidation zone sandstone type uranium deposit in Shanganning basin

    International Nuclear Information System (INIS)

    Wang Jinping

    1998-01-01

    As Compared with orogenic zone basin, which the interlayer oxidation zone sandstone type uranium deposits are found, the Shanganning basin a continental platform type basin is distinct either in the geodynamic background and the post-basin hydrogeological evolution or in the appearance of the metallogenetic dynamics-orogenesis. The prediction criteria summarized for interlayer oxidation zone type U-deposits in Middle Asia therefore can not be completely applied in such a basin. Based on analysis of the typical regional geological setting, the hydrogeology of the Meso-Cenozoic cover is studied in detail. Three hydrogeological cycles have been divided, and prospects of uranium deposits have been clarified and the most promising target have been proposed

  3. Biogenic non-crystalline U(IV) revealed as major component in uranium ore deposits

    Science.gov (United States)

    Bhattacharyya, Amrita; Campbell, Kate M.; Kelly, Shelly D.; Roebbert, Yvonne; Weyer, Stefan; Bernier-Latmani, Rizlan; Borch, Thomas

    2017-06-01

    Historically, it is believed that crystalline uraninite, produced via the abiotic reduction of hexavalent uranium (U(VI)) is the dominant reduced U species formed in low-temperature uranium roll-front ore deposits. Here we show that non-crystalline U(IV) generated through biologically mediated U(VI) reduction is the predominant U(IV) species in an undisturbed U roll-front ore deposit in Wyoming, USA. Characterization of U species revealed that the majority (~58-89%) of U is bound as U(IV) to C-containing organic functional groups or inorganic carbonate, while uraninite and U(VI) represent only minor components. The uranium deposit exhibited mostly 238U-enriched isotope signatures, consistent with largely biotic reduction of U(VI) to U(IV). This finding implies that biogenic processes are more important to uranium ore genesis than previously understood. The predominance of a relatively labile form of U(IV) also provides an opportunity for a more economical and environmentally benign mining process, as well as the design of more effective post-mining restoration strategies and human health-risk assessment.

  4. Dissolution of synthetic uranium dibutyl phosphate deposits in oxidizing and reducing chemical formulations

    Energy Technology Data Exchange (ETDEWEB)

    Rufus, A.L.; Sathyaseelan, V.S.; Narasimhan, S.V.; Velmurugan, S., E-mail: svelu@igcar.gov.in

    2013-06-15

    Graphical abstract: SEM of the U-DBP coated stainless steel coupon before and after exposure to chemical formulation containing acid permanganate at 80 °C. -- Highlights: •Combination of oxidation and reduction processes efficiently dissolves U-DBP deposits. •NP and NAC formulations are compatible with SS-304. •Dissolved uranium and added chemicals are effectively removed via ion exchangers. -- Abstract: Permanganate and nitrilotriacetic acid (NTA) based dilute chemical formulations were evaluated for the dissolution of uranium dibutyl phosphate (U-DBP), a compound that deposits over the surfaces of nuclear reprocessing plants and waste storage tanks. A combination of an acidic, oxidizing treatment (nitric acid with permanganate) followed by reducing treatment (NTA based formulation) efficiently dissolved the U-DBP deposits. The dissolution isotherm of U-DBP in its as precipitated form followed a logarithmic fit. The same chemical treatment was also effective in dissolving U-DBP coated on the surface of 304-stainless steel, while resulting in minimal corrosion of the stainless steel substrate material. Investigation of uranium recovery from the resulting decontamination solutions by ion exchange with a bed of mixed anion and cation resins showed quantitative removal of uranium.

  5. Exploration and discovery of the Pine Ridge uranium deposits, Powder River Basin, Wyoming, USA

    International Nuclear Information System (INIS)

    Doelger, M.

    2014-01-01

    The Pine Ridge uranium deposits are named for a newly identified area between the Pumpkin Buttes and Southern Powder River Basin (PRB) mining districts. This regional prospect, covering nine contiguous townships, is northwest of the Cameco Smith Ranch mine and west of the Uranium One Allemand-Ross project in Converse County, Wyoming. Surface mapping and 350+ measured sections of well exposed outcrops have identified 250 target sandstones and contributed to a model of the complex braided stream channel architecture within the Eocene Watsatch and Paleocene Fort Union Formations. The uranium-bearing sandstones occur in 3- D bundles of vertically aggrading river systems flowing into the PRB from distant uranium source areas of the Granite Mountains to the west and the northern Laramie Range to the south. Large volumes of mudstone overbank and swamp facies separate the individual river systems laterally, resulting in greater vertical reservoir continuity from sandstones stacking. At least five major paleo river systems have been identified and named. High organic content, within the host formations, and rising veils of hydrocarbon gases from underlying oil and gas deposits have resulted in classic roll front uranium deposits in individual sandstones and intervals. Mineralization in stacked sandstone bundles several hundred feet thick show a crescent-shaped distribution within the shallow mineralized interval “attic”, the “cellar” at the base of the alteration cell, and the furthest basin-ward “front door”. World-class uranium resource potential has been identified along 208 miles of redox boundary string length mapped from the 1522 control points consisting of outcrop data, pre-existing uranium drilling, oil and gas wells, and proprietary drilling in 2012 and 2013 by Stakeholder. All data is managed in ARC VIEW GIS with 3-D capability, which will be demonstrated. Very few restrictions apply to the project area. Uranium holes are permitted solely by the

  6. Proposition of a new genetic model for the Itataia uranium deposit, state of Ceara, Brazil

    International Nuclear Information System (INIS)

    Saad, S.; Munne, A.I.; Tanaka, A.Y.

    1984-01-01

    The Itataia uranium deposit is located within the central portion of the state of Ceara, being characterized mainly by collophanitic and feldspathic lithologies with some graphite concentrations. The mineralization occurs mainly in collophanitic rocks displaying compact texture and disseminates into marbles and feldspathic rocks. The characterization, within the structural- stratigraphic framework of Itataia, of a supergenic enrichment process through the remobilization and reconcentration of syngenetic uranium in marine carbonate rocks is proposed and discussed through the interpretation of Drill-hoel, geochemical seismic and structural data. (D.M.) [pt

  7. Mine waters of the flooded Příbram uranium deposit

    OpenAIRE

    Lusk, Karel

    2010-01-01

    From the Příbram deposit, which was the largest exploited uranium deposit in the Czech Republic, mine water has been drained under controlled conditions, treated and discharged into the Kocába River since the flooding of the deposit in October 2005. The amount of water drained in this way is determined at any particular moment by the volume of seepage from precipitation and surface water into the underground mine cavities. The draining of overbalance mine waters is carried out at two points t...

  8. Discussion on the genesis and mineralization of sandstone type uranium deposit in the southern-central Longchuanjiang basin, western Yunnan province

    International Nuclear Information System (INIS)

    Cai Yuqi; Li Mangen

    2002-01-01

    The author mainly discusses the character of the depositional systems, geological structures and ore-bearing series in the south-central Longchuanjiang basin, and points out that the uranium mineralization is closely related to the two depositional discontinuities caused by the tectonic evolution. Based on the characteristics of uranium mineralization in the area, pitchblende, uranium blacks and phosphuranylite are discovered in No. 382 uranium deposit and radiometric super-micro-minerals in No. 381 deposit. The research on the uranium mineralization age in No. 382 deposit shows that the mineralization in the south-central part of the basin has genetically multi-staged

  9. Method for detecting clusters of possible uranium deposits

    International Nuclear Information System (INIS)

    Conover, W.J.; Bement, T.R.; Iman, R.L.

    1978-01-01

    When a two-dimensional map contains points that appear to be scattered somewhat at random, a question that often arises is whether groups of points that appear to cluster are merely exhibiting ordinary behavior, which one can expect with any random distribution of points, or whether the clusters are too pronounced to be attributable to chance alone. A method for detecting clusters along a straight line is applied to the two-dimensional map of 214 Bi anomalies observed as part of the National Uranium Resource Evaluation Program in the Lubbock, Texas, region. Some exact probabilities associated with this method are computed and compared with two approximate methods. The two methods for approximating probabilities work well in the cases examined and can be used when it is not feasible to obtain the exact probabilities

  10. Hyperspectral Alteration Information from Drill Cores and Deep Uranium Exploration in the Baiyanghe Uranium Deposit in the Xuemisitan Area, Xinjiang, China

    Directory of Open Access Journals (Sweden)

    Qing-Jun Xu

    2017-05-01

    Full Text Available The Baiyanghe uranium deposit is a currently important medium-sized deposit in the Xuemisitan area, Xinjiang. The hydrothermal alteration in this deposit is closely related to the uranium mineralization of the deposit. In this study, hyperspectral data are collected from drill cores in the Baiyanghe uranium deposit using a FieldSpec4 visible-shortwave infrared spectrometer to study the hydrothermal alteration. The results reveal that the altered mineral assemblages have obvious zonation characteristics: (1 the upper section comprises long-wavelength illite and minor hematite and montmorillonite; (2 the middle section contains three types of illite (long-, medium- and short-wavelength illite and hematite; and (3 the lower section includes short-wavelength illite, chlorite and carbonate. Additionally, the variety in the characteristic absorption-peak wavelength of illite at 2200 nm gradually shifts to shorter wavelength and ranges between 2195 nm and 2220 nm with increasing depth, while the SWIR-IC (short-wavelength infrared illite crystallinity, a dimensionless quantity of the drill holes gradually increases from 0.2 to 2.1. These patterns reflect the hydrothermal fluid activity in the deposit, which features relatively high-temperature, high-pressure hydrothermal fluid in the deeper section and low-temperature, low-pressure hydrothermal fluid in the shallower section. Additionally, the uranium mineralization is located near the fracture zone, which represents the center of hydrothermal fluid activity or mineralization. This area has abundant alteration minerals, and the minerals illite (short- and medium-wavelength, hematite and fluorite can be used as uranium-prospecting indicators for uranium exploration in the deeper sections of the Baiyanghe uranium deposit.

  11. Hydrothermal uranium deposits containing molybdenum and fluorite in the Marysvale volcanic field, west-central Utah

    Science.gov (United States)

    Cunningham, C.G.; Rasmussen, J.D.; Steven, T.A.; Rye, R.O.; Rowley, P.D.; Romberger, S.B.; Selverstone, J.

    1998-01-01

    Uranium deposits containing molybdenum and fluorite occur in the Central Mining Area, near Marysvale, Utah, and formed in an epithermal vein system that is part of a volcanic/hypabyssal complex. They represent a known, but uncommon, type of deposit; relative to other commonly described volcanic-related uranium deposits, they are young, well-exposed and well-documented. Hydrothermal uranium-bearing quartz and fluorite veins are exposed over a 300 m vertical range in the mines. Molybdenum, as jordisite (amorphous MoS2, together with fluorite and pyrite, increase with depth, and uranium decreases with depth. The veins cut 23-Ma quartz monzonite, 20-Ma granite, and 19-Ma rhyolite ash-flow tuff. The veins formed at 19-18 Ma in a 1 km2 area, above a cupola of a composite, recurrent, magma chamber at least 24 ?? 5 km across that fed a sequence of 21- to 14-Ma hypabyssal granitic stocks, rhyolite lava flows, ash-flow tuffs, and volcanic domes. Formation of the Central Mining Area began when the intrusion of a rhyolite stock, and related molybdenite-bearing, uranium-rich, glassy rhyolite dikes, lifted the fractured roof above the stock. A breccia pipe formed and relieved magmatic pressures, and as blocks of the fractured roof began to settle back in place, flat-lying, concave-downward, 'pull-apart' fractures were formed. Uranium-bearing, quartz and fluorite veins were deposited by a shallow hydrothermal system in the disarticulated carapace. The veins, which filled open spaces along the high-angle fault zones and flat-lying fractures, were deposited within 115 m of the ground surface above the concealed rhyolite stock. Hydrothermal fluids with temperatures near 200??C, ??18OH2O ~ -1.5, ?? -1.5, ??DH2O ~ -130, log fO2 about -47 to -50, and pH about 6 to 7, permeated the fractured rocks; these fluids were rich in fluorine, molybdenum, potassium, and hydrogen sulfide, and contained uranium as fluoride complexes. The hydrothermal fluids reacted with the wallrock resulting in

  12. Ore reserve calculations of a sedimentary uranium deposit in Figueira, PR-Brazil

    International Nuclear Information System (INIS)

    Guerra, P.A.G.; Censi, A.C.; Marques, J.P.M.; Huijbregts, Ch.

    1978-01-01

    The are reserve calculations of a sedimentary uranium deposit in Figueira-PR-Brazil are presented. The evalution of reserves was based on chemical and/or radiometric analisys from boreholes. Geoestatistical methods were used to study the spacial correlation between radiometric and'in situ' uranium content and to calculate the equivalent uranium content without the need for chemical analysis. To this end, a new method was developed based on the regression between accumulated chemical and radiometric grades as determined by increasing thicknesses defined from the maximum peak of the γ-ray logs. Thus, the effect of non-focalization of the probe and of the continuous logging was eliminated. The system of evalution used was two-dimensional using classical Kriging to calculate thicknesses and accumulations determined using distinct cut-off grades. (Author) [pt

  13. Analysis on metallogenetic prospect of in-situ leachable sandstone-type uranium deposit in Chaoshui-Yabulai basin

    International Nuclear Information System (INIS)

    Jiang Minzhong; Wang Huaiwu

    2002-01-01

    Based on the regional geologic background, and results of high-sensitive airborne magnetic and air-borne radioactive surveys, and the interpretation of remote sensing images, ground geophysical and geochemical survey data, authors comprehensively analyse uranium-metallogenic geologic conditions for in-situ leachable sandstone-type uranium deposits in Chaoshui-Yabulai basin and have selected favourable target areas for uranium ore-formation

  14. Research on metallogenic conditions of intersection-type uranium ore-deposits in Zhongdong area, Northern Guangdong province

    International Nuclear Information System (INIS)

    Wang Zhengqi; Wu Lieqin; Zhang Guoyu

    2007-12-01

    The methods following as field geological investigation, trace element geo- chemistry and isotope geochemistry were used in this project. Based on geological and geochemical characteristics of Xiaoshui uranium ore deposits in Zhongdong area, Xiazhuang ore-field, Guangdong province, it could be concluded that: (1) The Provenance of Cretaceous mantle is a enriched mantle; (2) Silicified zone-type and intersection-type uranium ore are distinctness in the metallogenic period and mineralization process, and main metallogenic period of Xiaoshui uranium ore-deposit is 73.5 Ma; (3) The sources of uranium mineralization substance derived from enriched mantle; and (4)The intersection-type high grade uranium deposits were controlled by substances derived from mantle (contain with U, CO 2 , F, et al), tracks of intersection of NWW-across with NNE-trending faults and lithology of diabase. (authors)

  15. Conditions of uranium-bearing calcite formation in ore-enclosing sediments of the Semizbaj deposit (Kazakhstan)

    International Nuclear Information System (INIS)

    Kondrat'eva, I.A.; Maksimova, I.G.; Dojnikova, O.I.

    1995-01-01

    Consideration is given to results of investigation into uranium-bearing calcite, forming the cement of gravelly-sandy rocks of the Semizbaj uranium deposit. Core sampling in prospecting boreholes were used to establish geological conditions, place and time of uranium-bearing calcite formation. Calcite was investigated by optical, electron-microscope and radiographic methods. It is shown that uranium in calcite doesn't form its own mineral phase and exists in scattered state. Uranium in calcite-bearing minerals is present in isomorphic form. Uranium content in calcite was equal to 0.009-0.15 %. It is proposed that mineralization, formed in sedimentary rocks by processes of ground-stratum oxidation, is the source of uranium, enriching calcite. refs., 5 figs., 2 tabs

  16. Assessment of undiscovered resources in calcrete uranium deposits, Southern High Plains region of Texas, New Mexico, and Oklahoma, 2017

    Science.gov (United States)

    Hall, Susan M.; Mihalasky, Mark J.; Van Gosen, Bradley S.

    2017-11-14

    The U.S. Geological Survey estimates a mean of 40 million pounds of in-place uranium oxide (U3O8) remaining as potential undiscovered resources in the Southern High Plains region of Texas, New Mexico, and Oklahoma. This estimate used a geology-based assessment method specific to calcrete uranium deposits.

  17. The sedimentology and uranium mineralization of the Klipbankskraal deposit north of Merweville, C.P

    International Nuclear Information System (INIS)

    Le Roux, J.P.

    1982-08-01

    A sedimentological study was conducted on the farm Klipbankskraal, north-west of Merweville. The orebody is located in the Poortjie Member at the base of the Teekloof Formation. The mineralised sandstone, S1, is a tabular lithosome deposited in an ephemeral, braided river environment. It consists of two major and several minor mesocycles, with the upper major cycle showing evidence of having inherited the drainage pattern of the lower mesocycle. The vector mean azimuth of the sequence as a whole is towards 059 degrees. The uranium is present as stacked, tabular lenses associated with permeable zones in the immediate vicinity of erosional inter-cycle contacts. Although no obvious relationship exists between the uranium and channels or bars, the distribution of plant material was controlled by the current velocities which also controlled the type of sedimentary structures. Uranium occurs preferentially in fissile-weathering (horizontal-bedded) sandstone and mud-pebble conglomerate, both permeable lithologies, and in mudstone or silt-stone. Uranium is genetically related to other elements such as Mn, Mo, Cu, Co and Pb, which must have been constituents of the ore fluid. Uraniferous granites in the source areas probaly supplied most of the uranium

  18. Cathodoluminescence characteristics of sandstone and the implications for sandstone type No. 512 uranium deposit

    International Nuclear Information System (INIS)

    Liu Xiaodong; Guan Taiyang

    1998-12-01

    Cathodoluminescence (CL) technique, as a special petrologic tool, has been applied to the studies of uranium hosted sandstone from No. 512 uranium deposit located in Xinjiang Autonomous Region, Northwest China. The detrital grains including quartz, feldspar, debris and cements display distinguishing CL properties. The quartz grains mainly demonstrate brown and dark blue CL, feldspar grains demonstrate blue and bright blue CL, calcite cement displays bright yellow-orange and orange-red CL with significant CL zoning, while the debris, mud and sand cements have dark red CL, multicolor CL or non-luminescence. The characteristics of overgrowth, fracture healing, and the original contact relations of detrital grains appear much more significant with CL than that with conventional visual methods. Much more information can be contributed by CL technique to decipher the provenance area, to explain the cementation, consolidation and other diagenesis processes of sandstone. The CL technique also provides and efficient tool for identifying detrital grains and cements, and for more precisely estimating the proportions of various detrital grains and cement components in sandstone. The CL emission of uranium hosted sandstone revealed the existence of radiation-damage rims of quartz grains at the places with a little or no uranium minerals nearby, which may imply a uranium-leaching episode during the diagenesis of sandstone

  19. Exploration of method determining hydrogeologic parameters of low permeability sandstone uranium deposits

    International Nuclear Information System (INIS)

    Ji Hongbin; Wu Liwu; Cao Zhen

    2012-01-01

    A hypothesis of regarding injecting test as 'anti-pumping' test is presented, and pumping test's 'match line method' is used to process data of injecting test. Accurate hydrogeologic parameters can be obtained by injecting test in the sandstone uranium deposits with low permeability and small pumping volume. Taking injecting test in a uranium deposit of Xinjiang for example, the hydrogeologic parameters of main ore-bearing aquifer were calculated by using the 'anti-pumping' hypothesis. Results calculated by the 'anti-pumping' hypothesis were compared with results calculated by water level recovery method. The results show that it is feasible to use 'anti-pumping' hypothesis to calculate the hydrogeologic parameters of main ore-bearing aquifer. (authors)

  20. Measurement conditions of natural soil thermoluminescence and their application in a granite type uranium deposit

    International Nuclear Information System (INIS)

    Chen Yue; Yang Yaxin; Liu Qingcheng

    2009-01-01

    A measuring method of natural soil thermoluminescence is used for prospecting of uranium deposits. The better effects are obtained by using the method, but the parameters selected have significant effects on the intensity of soil thermoluminescent. So, the measuring parameters are selected according to the different soil samples. Based on the measuring 1 000 soil samples of granite type uranium deposit,the optimum heating up program of natural soil thermoluminescence is obtained, that is, preheating, lasting heating, constant temperature and the halting heating. The parameters selected are as follows: the heating rate being 15 degree C/s, the temperatures of the first and second constant temperature being 135 degree C and 400 degree C respectively. Using the selected parameters for measuring soil samples from a known mining area in Guangdong province, the result indicates that the abnormities of thermoluminescence have corresponding relations with the underground orebodies. (authors)

  1. Uranium

    International Nuclear Information System (INIS)

    1982-01-01

    The development, prospecting, research, processing and marketing of South Africa's uranium industry and the national policies surrounding this industry form the headlines of this work. The geology of South Africa's uranium occurences and their positions, the processes used in the extraction of South Africa's uranium and the utilisation of uranium for power production as represented by the Koeberg nuclear power station near Cape Town are included in this publication

  2. Distribution of Iron-Oxidizing Bacteria in the Nordic Uranium Tailings Deposit, Elliot Lake, Ontario, Canada

    OpenAIRE

    Silver, M.

    1987-01-01

    Iron-oxidizing bacteria are present within the top 2 m (but not always at the surface) and near the water table-capillary fringe of the vegetated Nordic uranium deposit, Elliot Lake, Ontario, Canada. They are distributed uniformly in the top 0.5 m of unvegetated tailings. The locations of these bacteria correlate with zones of pyrite oxidation as delineated in previous studies by the formation of soluble iron and sulfate. Heterotrophic bacteria are also present in the tailings, with greatest ...

  3. Uranium

    International Nuclear Information System (INIS)

    Stewart, E.D.J.

    1974-01-01

    A discussion is given of uranium as an energy source in The Australian economy. Figures and predictions are presented on the world supply-demand position and also figures are given on the added value that can be achieved by the processing of uranium. Conclusions are drawn about Australia's future policy with regard to uranium (R.L.)

  4. Uranium

    International Nuclear Information System (INIS)

    Toens, P.D.

    1981-03-01

    The geological setting of uranium resources in the world can be divided in two basic categories of resources and are defined as reasonably assured resources, estimated additional resources and speculative resources. Tables are given to illustrate these definitions. The increasing world production of uranium despite the cutback in the nuclear industry and the uranium requirements of the future concluded these lecture notes

  5. Uranium

    International Nuclear Information System (INIS)

    Battey, G.C.; McKay, A.D.

    1988-01-01

    Production for 1986 was 4899 t U 3 O 8 (4154 t U), 30% greater than in 1985, mainly because of a 39% increase in production at Ranger. Exports for 1986 were 4166 t U 3 O 8 at an average f.o.b. unit value of $40.57/lb U 3 O 8 . Private exploration expenditure for uranium in Australia during the 1985-86 fiscal year was $50.2 million. Plans were announced to increase the nominal capacity of the processing plant at Ranger from 3000 t/year U 3 O 8 to 4500 t and later to 6000 t/year. Construction and initial mine development at Olympic Dam began in March. Production is planned for mid 1988 at an annual rate of 2000 t U 3 O 8 , 30 000 t Cu, and 90 000 oz (2800 kg) Au. The first long-term sales agreement was concluded in September 1986. At the Manyingee deposit, testing of the alkaline solution mining method was completed, and the treatment plant was dismantled. Spot market prices (in US$/lb U 3 O 8 ) quoted by Nuexco were generally stable. From January-October the exchange value fluctuated from US$17.00-US$17.25; for November and December it was US$16.75. Australia's Reasonably Assured Resources of uranium recoverable at less than US$80/kg U at December 1986 were estimated as 462 000 t U, 3000 t U less than in 1985. This represents 30% of the total low-cost RAR in the WOCA (World Outside the Centrally Planned Economy Areas) countries. Australia also has 257 000 t U in the low-cost Estimated Additional Resources Category I, 29% of the WOCA countries' total resources in this category

  6. The siliceous-calcareous-argillaceous rock type uranium deposit in south subzone of Western Qinling

    International Nuclear Information System (INIS)

    Qian Farong; Zhou Dean; Ji Hongfang

    1995-11-01

    The siliceous-calcareous-argillaceous rock type uranium deposit in south subzone of western Qinling is an inland found type deposit with specific mineralization and good potentiality. The mineralization distributes along definite horizons and occurs in siliceous layer and lenses of siliceous-calcareous rocks. Orebody presents in forms of stratoid, lenticular and irregular veins and controlled by factorial structures. Ore is identified as massive and sandy and each characterized by various mineral compositions and element associations. The study shows that the mineralizing materials are mainly derived from ore-bearing strata. The metallogenic environment has characteristics of middle-low temperature and supergene The metallogenesis underwent three stages: (1) Sedimentation-diagenesis of the ore-bearing strata led to preliminary concentration of uranium; (2) Polytectonic activities accompanied by underground hydrothermal process resulted in the industrial concentration of uranium; and (3) Orebody reworked by oxidation-denudation and leaching, locally has taken place secondary concentration. The deposit in origin attributes to polygenesis dominated by underground hydrothermal metallogenesis. Main metallogenic epoch happens during the periods of Late Yanshan and Himalayan. According to the geological-tectonic conditions the further prospecting direction in study area is proposed. (3 refs., 5 figs., 9 tabs.)

  7. Geology and recognition criteria for uranium deposits of the quartz-pebble conglomerate type. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Button, A.; Adams, S.S.

    1981-03-01

    This report is concerned with Precambrian uraniferous conglomerates. This class of deposit has been estimated to contain between approximately 16 and 35 percent of the global uranium reserve in two rather small areas, one in Canada, the other in South Africa. Similar conglomerates, which are often gold-bearing, are, however, rather widespread, being found in parts of most Precambrian shield areas. Data have been synthesized on the geologic habitat and character of this deposit type. The primary objective has been to provide the most relevant geologic observations in a structural fashion to allow resource studies and exploration to focus on the most prospective targets in the shortest possible time.

  8. The Outlook on Potential Uranium ISL Mining at Nyota Deposit (Tanzania)

    International Nuclear Information System (INIS)

    Boytsov, A.; Stander, S.; Martynenko, V.

    2014-01-01

    Conclusion: • The Nyota deposit is a world class deposit, which holds over 50Mlb which is potentially amenable to ISR. • Significant resources upside potential. • Initial ISL testing has yielded encouraging results, which should be followed up. • The ISR project is currently at the R&D stage, and the next steps have been identified and planned. • Technical, commercial and SHEQ challenges remains that must be overcome. • Uranium One will continue to investigate the ISR potential via a responsible, toll gated approach. • Successful testing could unlock a new ISL production region.

  9. Geology and recognition criteria for uranium deposits of the quartz-pebble conglomerate type. Final report

    International Nuclear Information System (INIS)

    Button, A.; Adams, S.S.

    1981-03-01

    This report is concerned with Precambrian uraniferous conglomerates. This class of deposit has been estimated to contain between approximately 16 and 35 percent of the global uranium reserve in two rather small areas, one in Canada, the other in South Africa. Similar conglomerates, which are often gold-bearing, are, however, rather widespread, being found in parts of most Precambrian shield areas. Data have been synthesized on the geologic habitat and character of this deposit type. The primary objective has been to provide the most relevant geologic observations in a structural fashion to allow resource studies and exploration to focus on the most prospective targets in the shortest possible time

  10. A new genetic understanding for the mineralized breccia from the uranium deposit No.320

    International Nuclear Information System (INIS)

    Min Maozhong; Wang Xiangyun; Shen Baopei; Wen Guangdou; Fan Tao

    1996-01-01

    The hydrothermal cryptoexplosion was found in the uranium deposit No.320 for the first time. A polygenetic understanding is presented that the mineralized breccia in the deposit is mainly attributed to tectonite genesis and secondarily attributed to the hydrothermal cryptoexplosion. Geodes in breccia are of multigenesis, of these, the geodes from tectonic breccia are the most important, other geodes may be attributed to the hydrothermal cryptoexplosion, dissolution and dropping (stripping) of coarse biological fossils, paleokarst and modern hot spring water corrosion, dissolution of pyrite in rocks, etc. It is inferred that the original rocks of silicified breccia are silicalite, carbonaceous shale and carbonaceous pelitic limestone rich in biogenic debris

  11. Uranium-Series Disequilibria in the Groundwater of the Shihongtan Sandstone-Hosted Uranium Deposit, NW China

    Directory of Open Access Journals (Sweden)

    Xinjian Peng

    2015-12-01

    Full Text Available Uranium (U concentration and the activities of 238U, 234U, and 230Th were determined for groundwaters, spring waters, and lake water collected from the Shihongtan sandstone-hosted U ore district and in the surrounding area, NW China. The results show that the groundwaters from the oxidizing aquifer with high dissolved oxygen concentration (O2 and oxidation-reduction potential (Eh are enriched in U. The high U concentration of groundwaters may be due to the interaction between these oxidizing groundwaters and U ore bodies, which would result in U that is not in secular equilibrium. Uranium is re-precipitated as uraninite on weathered surfaces and organic material, forming localized ore bodies in the sandstone-hosted aquifer. The 234U/238U, 230Th/234U, and 230Th/238U activity ratios (ARs for most water samples show obvious deviations from secular equilibrium (0.27–2.86, indicating the presence of water-rock/ore interactions during the last 1.7 Ma and probably longer. The 234U/238U AR generally increases with decreasing U concentrations in the groundwaters, suggesting that mixing of two water sources may occur in the aquifer. This is consistent with the fact that most of the U ore bodies in the deposit have a tabular shape originati from mixing between a relatively saline fluid and a more rapidly flowing U-bearing meteoric water.

  12. Exploration-systems approach to the Copper Mountain area uranium deposits, central Wyoming. National Uranium Resource Evaluation

    International Nuclear Information System (INIS)

    Sayala, D.; Lindgren, J.; Babcock, L.

    1982-09-01

    This report presents the results of multidisciplinary investigations of uranium deposits in the Copper Mountain District of central Wyoming. Although the studies on which the report is based began in 1977, work on the project has been discontinuous and was conducted partly by investigators no longer on the project. The project report represents an effort by the authors to compile and interpret the various data and to draw reasonable conclusions. Although an attempt is made to integrate, where possible, the results of different studies (or surveys), the report is organized into individual sections that present methods and results for each approach used. Investigations reported separately include geology, geochemistry, geophysics, and emanometry. These are aimed at characterizing and understanding the Copper Mountain uranium district and aiding in the detection of similar districts. A summary of overall project results, a comparison of the usefulness of individual approaches or combinations of approaches, and conclusions are presented in separate report sections for the project as a whole. All six sections in this report have been abstracted and indexed

  13. Diversity, metal resistance and uranium sequestration abilities of bacteria from uranium ore deposit in deep earth stratum.

    Science.gov (United States)

    Islam, Ekramul; Sar, Pinaki

    2016-05-01

    Metal resistance and uranium (U) sequestration abilities of bacteria residing in subsurface U ore was investigated using 122 pure culture strains isolated through enrichment. The cumulative frequencies of isolates resistant to each metal tested were as follows: As(V), 74%; Zn, 58%; Ni, 53%; Cd, 47%; Cr(VI), 41%; Co, 40%; Cu, 20%; and Hg, 4%. 16S rRNA gene analysis revealed that isolated bacteria belonged to 14 genera with abundance of Arthrobacter, Microbacterium, Acinetobacter and Stenotrophomonas. Cobalt did not interfere with the growth of most of the bacterial isolates belonging to different groups while U allowed growth of four different genera of which Stenotrophomonas and Microbacterium showed high U tolerance. Interestingly, tolerance to Ni, Zn, Cu, and Hg was observed only in Microbacterium, Arthrobacter, Paenibacillus¸ and Acinetobacter, respectively. However, Microbacterium was found to be dominant when isolated from other five different metal enrichments including U. Uranium removal study showed that 84% of the test bacteria could remove more than 50mgUg(-1) dry weight from 80 or 160mgL(-1) U within 48h. In general, Microbacterium, Arthrobacter and Acinetobacter could remove a higher amount of U. High resolution transmission electron microscopy (HRTEM) study of U exposed cells revealed that accumulated U sequestered mostly around the cell periphery. The study highlights that indigenous U ore deposit bacteria have the potential to interact with U, and thus could be applied for bioremediation of U contaminated sites or wastes. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Forms of uranium associated to silica in the environment of the Nopal deposit (Mexico)

    Science.gov (United States)

    Allard, T.; Othmane, G.; Menguy, N.; Vercouter, T.; Morin, G.; Calas, G.; Fayek, M.

    2011-12-01

    The understanding of the processes that control the transfers of uranium in the environment is necessary for the safety assessement of nuclear waste repositories. In particular, several poorly ordered phases (e.g. Fe oxihydroxides) are expected to play an important role in trapping uranium from surface waters. Among them, natural systems containing amorphous silica are poorly documented. A former study from the environment of the Peny mine (France) showed the importance of silica in uranium speciation [1]. The Nopal uranium deposit is located in volcanic tuff from tertiary period. It hosted several hydrothermal alteration episodes responsible for clay minerals formation. A primary uranium mineralisation occurred in a breccia pipe, consisting in uraninite, subsequently altered in secondary uranium minerals among which several silicates. Eventually, opal was formed and coated uranyl silicates such as uranophane and weeksite [2], [3]. Opals also contain minor amounts of uranium. The Nopal deposit is still considered as a natural analogue of high level nuclear waste repository located in volcanic tuff. It may be used to reveal the low temperature conditions of trapping of uranium in systems devoid of iron oxides such as silica-containing ones. The aim of this study is then to determine the uranium speciation, and its possible complexity, associated to these opals that represent a late trapping episode. It will provide insights ranging from the micrometer scale of electron microscopies to the molecular scale provided by fluorescence spectroscopy. Three samples of green or yellow opals have been analysed by a combination of complementary tools including scanning electron microscopy (SEM) on cross-sections, transmission electron microscopy (TEM) on focused ion beam (FIB) films, cathodoluminescence and time-resolved laser fluorescence spectroscopy (TRLFS). Uranium speciation was found to be complex. We first evidence U-bearing microparticles of beta-uranophane Ca[(UO2)(Si

  15. On a Bayesian estimation procedure for determining the average ore grade of a uranium deposit

    International Nuclear Information System (INIS)

    Heising, C.D.; Zamora-Reyes, J.A.

    1996-01-01

    A Bayesian procedure is applied to estimate the average ore grade of a specific uranium deposit (the Morrison formation in New Mexico). Experimental data taken from drilling tests for this formation constitute deposit specific information, E 2 . This information is combined, through a single stage application of Bayes' theorem, with the more extensive and well established information on all similar formations in the region, E 1 . It is assumed that the best estimate for the deposit specific case should include the relevant experimental evidence collected from other like formations giving incomplete information on the specific deposit. This follows traditional methods for resource estimation, which presume that previous collective experience obtained from similar formations in the geological region can be used to infer the geologic characteristics of a less well characterized formation. (Author)

  16. A geostatistical study of the uranium deposit at Kvanefjeld, the Ilimaussaq intrusion, South Greenland

    International Nuclear Information System (INIS)

    Lund Clausen, F.

    1982-05-01

    The uranium deposit at Kvanefjeld within the Ilimaussaq intrusion in South Greenland has been tested by diamond drilling, hole logging, chip sampling and field gamma-spectrometric surveys. Based on these different types of spatially distributed samples the uranium variation within the deposit was studied. The spatial variation, which comprises a large random component, was modelled, and the intrinsic function was used to establish gradetonnage curves by the best linear unbiased estimator of geostatistics (kriging). From data obtained by a ground surface gamma-spectrometric survey it is shown that the uranium variation is possibly subject to a spatial anisotropy consistent with the geology. The uranium variation has a second-order stationarity. A global estimation of the total reserves shows that single block grade values are always estimated with high errors. This is mainly caused by the poor spatial structure and the very sparse sampling pattern. The best way to solve this problem appears to be a selective type of kriging. The overall uranium reserves are estimated as 23600 tons with a mean grade of 297 ppm (cutoff grade 250 ppm U). Studies of data from a test adit show that local geostatistical estimation can be done with acceptably small errors provided that a close sampling pattern is used. A regression relationship is established to correct field gamma-spectrometric measures of bulk grades towards truer values. Multivariate cluster and discriminant analyses were used to classify lujavrite samples based on their trace element content. Misclassification is due to a possibly continuous transition between naujakasite lujavrite and arfvedsonite lujavrite. Some of the main mineralogical differences between the geological units are identified by the discriminating effect of the individual variable. (author)

  17. Geological characteristics of granite type uranium deposits in middle of Inner Mongolia in comparison with south China

    International Nuclear Information System (INIS)

    Wang Gui

    2012-01-01

    Granites extensively distributed in middle of Inner Mongolia and South China, namely Caledonian, Hercynian and Yanshanian. Some of the intrusive are composed of granites which belong to different ages. Some of the uranium deposits were found inside the granite bodies or in sedimentary rocks and meta sedimentary rocks along the exocontact zone. Granite rock was comparing in middle Inner Mongolia and South China, including Uranium ore-forming geological conditions. ore-forming process and Ore-controlling factors. Think the Uranium ore-forming geological conditions is similar; ore-forming process is mainly for low-mid temperature hot liquid; Uranium ore bodies (uranium mineralization) was controlled by fracture. Explain granite type uranium mineralization potential is tremendous in middle of Inner Mongolia. (author)

  18. Clay minerals suitable for overpack in waste repositories: evidence from uranium deposits

    International Nuclear Information System (INIS)

    Brookins, D.G.

    1980-01-01

    Various clay minerals have been proposed for overpack around radioactive waste canisters. The laboratory studies of the migration of elements from the nuclear waste through proposed overpack have resulted in some disagreement. As an alternative approach to the laboratory studies, a review of data for the uranium deposits of the Grants, New Mexico, mineral belt has been undertaken. This paper reviews the evidence from the clay mineralogy, the Rb-Sr systematics and the trace element analyses of the clay size (<2μ) fraction of rocks from the uranium ore zones and the barren host rocks. The <2μ fraction is dominated by clay minerals, but small amounts of other minerals and organic matter are present as well. The information from uranium deposits suggests that chlorite will form during the mineralization process from pre-existing montmorillonite or illite or mixed-layered illite-montmorillonite accompanied by fixation of V, Mo, Se, As, REE, Th. Based on this fact coupled with the observation that the barren rocks are magnetite-rich under low Eh conditions, then an argument for the use of the very abundant sand-poor shales of the Morrison Formation as material suitable for overpack can be made. In the event of canister failure, any escaping actinides, actinide daughters or fission products should react efficiently with the intermediate cation exchange capacity (CEA) montmorillonite-illite-rich material and promote low CEC chlorite formation and sorption of actinides and lanthanides. Formation of such low CEC chlorite would not only scavenge the earliest radioactive elements released but would also retard fluid flow through the surrounding overpack by fissure filling which in turn would further impede radionuclide escape. The distribution of trace elements around uranium deposits of the Grants mineral belt is entirely compatible with such a scenario

  19. Preliminary studies on environment assessment around Wahkyn uranium deposit, West Khasi Hills District, Meghalaya: a hydro-pedo geochemical approach

    International Nuclear Information System (INIS)

    Umamaheswar, K.; Sinha, K.K.; Murugan, M.G.; Balasubramani, S.; Pandey, Alok

    2004-01-01

    Environmental baseline study is an important step in the environmental impact assessment of the uranium deposit. It forms background for mining and milling project, on the local environment. Baseline data collection programme was initiated in the later part of 2001 after identifying sampling sites covering the Wahkyn uranium deposit. Workable size of uranium with an average grade of 0.101 % U 3 O 8 has been established in coarse to medium grained, immature, grey to dark grey feldspathic sandstone with abundant carbonaceous matter and pyrite. Systematic stream water samples in conjunction with soil and stream sediment samples were collected periodically from 20 permanent sample sites spread over 4.5 sq km, located in perennial streams draining through the Wahkyn uranium deposit area

  20. Uranium deposit removal from the Oak Ridge Gaseous Diffusion Plant K-25 Building

    International Nuclear Information System (INIS)

    Ladd, L.D.; Stinnett, E.C. Jr.; Hale, J.R.; Haire, M.J.

    1993-01-01

    The Oak Ridge Gaseous Diffusion Plant went into operation as the first plant to separate uranium by the gaseous diffusion process. It was built during World War II as part of the U.S. Army Corps of Engineers' Manhattan Project. Its war-time code name was K-25, which was also the name of the first uranium separation building constructed at the installation. The K-25 building was considered an engineering miracle at the time of its construction. Built in a U shape ∼1 mile long and 400 ft wide, it housed complex and unique separation equipment. Despite its size and complexity, it was made fully operational within <2 yr after construction began. The facility operated successfully for more than 20 yr until it was placed in a standby mode in 1964. It is now clear the K-25 gaseous diffusion plant will never again be used to enrich uranium. The U.S. Department of Energy, therefore, has initiated a decontamination and decommission program. This paper discusses various procedures and techniques for addressing critical mass, uranium deposits, and safeguards issues

  1. Depositional characteristics of cretaceous cover in Xiangyangshan area of Heilongjiang province and analysis on prospect for sandstone hosted interlayer oxidation zone type uranium deposits

    International Nuclear Information System (INIS)

    Cai Yuqi; Li Shengxiang; Dong Wenming

    2003-01-01

    The depositional systems and characteristics of Cretaceous Cover depositional facies are discussed. In combination with logging curves in Xiangyangshan area, two depositional systems (namely, alluvial fan depositional system and alluvial plain depositional system) and five types of depositional facies are distinguished. Results of detailed research are given for each depositional facies in aspects of lithology, depositional structure, logging curve and grain size distribution pattern. Temporal and spatial distribution features of the depositional facies and the development features of interlayer oxidation zones of the second member of Quantou Formation are analyzed. Finally, conclusions on prospects for sandstone-hosted interlayer oxidation zone type uranium deposits in the study area are given in the aspect of depositional facies. (authors)

  2. Geophysical Investigations of the Uranium Mineralized Formation in the Coaly Black Shale Deposits in Korea

    Science.gov (United States)

    Kim, C.; Son, J.; Yoon, H.; Park, S.

    2011-12-01

    , two locations of concern with low resistivity anomalies and with high IP response were selected to drill down to 300-500m depth, based on the geological, geochemical, and geophysical investigations. The drilling operation has penetrated two formations of uranium-bearing coaly black slate at the different depths. The integrated geophysical investigation techniques including the construction of the conceptual geophysical model and the selection of appropriate geophysical methods, based on the geological and geochemical results, were useful for the uranium exploration in this study and can be applied to other sites of uranium-bearing ore deposits with similar geologic conditions.

  3. Uranium deposits associated to tertiary acid volcanism of the Pena Blanca Sierra (Chihuahua, Mexico)

    International Nuclear Information System (INIS)

    Aniel, B.

    1986-12-01

    The uraniferous deposits located in the Sierra de Pena Blanca (Chihuahua, Mexico) are the consequence of successive events that modified acid volcanic rocks. The devitrification of the Nopal Formation, vitroclastic tuffs, is esential in the cooling history because it releases uranium that becomes available. The uranium present in fluids as uranylcarbonate complexes, precipitate along the lamellea of hematite (exsolutions of the ilmenites). The presence of sulfur causes the destabilization of the ilmenites with uranium oxide (pitchblende - titanium oxide - pyrite), the pseudomorph of magnetites (pitchblende - pyrite) and the transformation of hematite into pyrite. The silice coming from the kaolinization of feldspars recristallizes as microcristalline quartz so that the rock appears compact. Fractures cause the uplifting of the lower unit of Nopal formation. It has been altered to montmorillonite. A carbonatation of this tuff has been observed and these two types of alteration occur after kaolinization. The Escuadra formation overlies the Nopal formation. The deposition takes place on an eroded basement where a soil developed. The two formations will together undergo transformations due to the saturation level and the primary ore will be only oxidized or oxidized, transported and reconcentrated. Late and localized thermal activities have been observed and may be the result of tectonic movements occurring after the supergene modification [fr

  4. Uranium comminution age tested by the eolian deposits on the Chinese Loess Plateau

    Science.gov (United States)

    Li, Le; Liu, Xiangjun; Li, Tao; Li, Laifeng; Zhao, Liang; Ji, Junfeng; Chen, Jun; Li, Gaojun

    2017-06-01

    The 234U/238U ratio of fine particles can record the time since their separation from bed rock because of the disruption of uranium series equilibrium introduced by the recoil of daughter 234Th nuclei (precursor of 234U) out of particle surfaces during the decay of 238U. Application of the uranium comminution age method, which has great potential in tracing production and transportation of sediments is however complicated by the weathering dissolution of 234U depleted particle surfaces, the difficulty in determining the fraction of recoiled nuclei, and the precipitation of exogenetic 234U. Here we minimize these complications by using a newly developed precise size separation using electroformed sieve, and a chemical protocol that involves reductive and oxidative leaching. Eolian deposits collected from the Chinese Loess Plateau (CLP) were used to test the validity of our method. Possible effects of weathering dissolution were also evaluated by comparing samples with different weathering intensities. The results show decreasing 234U/238U ratios in fine eolian particles with increasing sedimentation age, agreeing well with the theoretical prediction of the comminution age model. This successful application of the uranium comminution age approach to the eolian deposits on the CLP is also aided by a stable dust source, the low weathering intensity, the lack of consolidation, and the well-defined age model of the deposits. A transportation time of 242 ± 18 ka was calculated for the eolian deposits, which indicates a long residence time, and thus extensive mixing, of the dust particles in source regions, partly explaining the stable and homogeneous composition of the eolian dust over glacial-interglacial cycles.

  5. The sedimentology and uranium mineralisation of the Banksgaten deposit, Sutherland district

    International Nuclear Information System (INIS)

    Le Roux, J.P.

    1982-08-01

    As part of its research program, NUCOR carried out a sedimentological investigation of the Banksgaten uranium deposit discovered by Esso Minerals. The Banksgaten prospect is situated on a promontory of the Nuweveld Escarpment, 35 km south-east of Sutherland. The six prominent sandstone units exposed in the study area form part of the arenaceous Oukloof Member of the Teekloof Formation. Palaeocurrent studies show a wide variation in transport direction. However, the vector mean palaeocurrent trend is towards the north-north-east. The sedimentological environment is a distal braided river forming part of a deltaic plain. The uranium mineralisation occurs on three stratigraphic levels and is concentrated almost exclusively in the channels of the different sandstones. These channels are vertically superimposed and probably inherited the drainage pattern of pre-existing channels

  6. Formation conditions and prospecting criteria for sandstone uranium deposit of interlayer oxidation type

    International Nuclear Information System (INIS)

    Huang Shijie

    1994-01-01

    This paper comprehensively analyses the geotectonic setting and favourable conditions, such as structure of the basin, sedimentary facies and paleogeography, geomorphology and climate, hydrodynamics and hydrogeochemistry, the development of interlayered oxidation etc, necessary for the formation of sandstone uranium deposit of interlayered oxidation type. The following prospecting criteria is proposed, namely: abundant uranium source, arid climate, stable big basin, flat-lying sandstone bed, big alluvial fan, little change in sedimentary facies, intercalation of sandstone and mudstone beds, shallow burying of sandstone bed, well-aquiferous sandstone bed, high permeability of sandstone bed, development of interlayered oxidation, and high content of reductant in sandstone. In addition, the 6 in 1 hydrogenic genetic model is proposed

  7. Phyllitic minerals in hydrothermal uranium deposits. I. Crystalchemistry of relict and newly formed micas

    International Nuclear Information System (INIS)

    Leroy, Jacques; Cathelineau, Michel

    1982-01-01

    Several generations of white micas have been recognised in four two mica granite massifs which are associated with uranium deposits in the Hercynian chain. These different generations correspond to distinct geological phenomena belonging to the deuteric and hydrothermal stages of the history of these massifs. Crystalchemical studies of these micas with the aid of the electronic microprobe show that each of these phenomena corresponds a phengite of different, well defined compositions. An increase in the phengitic character and a decrease in the paragonite component are observed over time. Strong similarities exist between micas of the same generation belonging to different granite massifs. The study of the evolution of the earliest deuteric micas during later hydrothermal phenomena, mica episyenitisation and deposition of pitchblende, has shown two opposed trends. In the case of mica episyenitisation, the micas tend to reequilibrate, while in the case of pitchblende deposition and the vein stage in general, the micas preserve their primary character [fr

  8. The Cigar Lake uranium deposit: An analogue for nuclear fuel waste disposal

    International Nuclear Information System (INIS)

    Goodwin, B.W.; Cramer, J.J.; McConnell, D.B.

    1989-01-01

    Cigar Lake is the site of an ore deposit containing exceptionally high concentrations of uranium. This deposit has features analogous to those of concepts being developed internationally for the disposal of nuclear fuel waste deep in crystalline rock formations. An understanding of the geological history of the Cigar Lake deposit can therefore provide useful insight into the long term behaviour of nuclear waste vaults constructed in bedrock. For assessments that have been completed, studies at Cigar Lake can be used to provide validation support for certain aspects of the models and data. They may also provide support for the overall results of the assessments. In the discussion below, we focus on the second of these topics and examine how information from Cigar Lake contributes to the validation of environmental assessments of a geological disposal system. 7 refs, figs, tab

  9. Geological-geochemical evidence for deep fluid action in Daqiaowu uranium deposit, Zhejiang province

    International Nuclear Information System (INIS)

    Qiu Linfei; Ou Guangxi; Zhang Jianfeng; Zhang Min; Jin Miaozhang; Wang Binghua

    2009-01-01

    Through the contrast study of petrography, micro thermometry and laser Raman ingredient analysis of fluid inclusion, this paper has verified the basic nature of ore-forming fluid (temperature, salinity and ingredient) in daqiaowu uranium deposit, discussed the origin of the ore-forming fluid with its structure character and geology-geochemistry character. The testing results indicats that ore-forming temperature of this deposit is between 200 degree C and 250 degree C in main metallogenetic period, which belongs to middle temperature hydrothermal. The ore-forming fluids are of middle-high salinity and rich in valatility suchas CO 2 , H 2 , CH 4 . To sum up, the deposit mineralization process should be affected by the deep fluid primarily, and the ore-forming fluid is mainly the mantle fluid.(authors)

  10. Comprehensive geophysical survey technique in exploration for deep-buried hydrothermal type uranium deposits in Xiangshan volcanic basin, China

    International Nuclear Information System (INIS)

    Ke, D.

    2014-01-01

    According to recent drilling results, uranium mineralization has been found underground more than 1000 m deep in the Xiangshan volcanic basin, in where uranium exploration has been carried out for over 50 years. This paper presents a comprehensive geophysical survey technique, including audio magnetotelluric method (AMT), high resolution ground magnetic and radon survey, which aim to prospect deep-buried and concealed uranium deposits in Xiangshan volcanic basin. Based on research and application, a comprehensive geophysical technique consisting of data acquisition, processing and interpretation has been established. Concealed rock and ore-controlling structure buried deeper than 1000 m can be detected by using this technique. Moreover, one kind of anti-interference technique of AMT survey is presented, which can eliminate the interference induced by the high-voltage power lines. Result of AMT in Xiangshan volcanic basin is demonstrated as high-low-high mode, which indicates there are three layers in geology. The upper layer with high resistivity is mainly the react of porphyroclastic lava. The middle layer with low resistivity is metamorphic schists or dellenite whereas the lower layer with high resistivity is inferred as granite. The interface between middle and lower layer is recognized as the potential zone for occurrence of uranium deposits. According to the corresponding relation of the resistivity and magnetic anomaly with uranium ore bodies, the tracing model of faults and interfaces between the different rocks, and the forecasting model of advantageous area for uranium deposits have been established. In terms of the forecasting model, some significant sections for uranium deposits were delineated in the west of the Xiangshan volcanic basin. As a result, some achievements on uranium prospecting have been acquired. High grade economic uranium ore bodies have been found in several boreholes, which are located in the forecasted zones. (author)

  11. Comparison of potential radiological consequences from a spent-fuel repository and natural uranium deposits

    Energy Technology Data Exchange (ETDEWEB)

    Wick, O.J.; Cloninger, M.O.

    1980-09-01

    A general criterion has been suggested for deep geological repositories containing spent fuel - the repositories should impose no greater radiological risk than due to naturally occurring uranium deposits. The following analysis investigates the rationale of that suggestion and determines whether current expectations of spent-fuel repository performance are consistent with such a criterion. In this study, reference spent-fuel repositories were compared to natural uranium-ore deposits. Comparisons were based on intrinsic characteristics, such as radionuclide inventory, depth, proximity to aquifers, and regional distribution, and actual and potential radiological consequences that are now occurring from some ore deposits and that may eventually occur from repositories and other ore deposits. The comparison results show that the repositories are quite comparable to the natural ore deposits and, in some cases, present less radiological hazard than their natural counterparts. On the basis of the first comparison, placing spent fuel in a deep geologic repository apparently reduces the hazard from natural radioactive materials occurring in the earth's crust by locating the waste in impermeable strata without access to oxidizing conditions. On the basis of the second comparison, a repository constructed within reasonable constraints presents no greater hazard than a large ore deposit. It is recommended that if the naturally radioactive environment is to be used as a basis for a criterion regarding repositories, then this criterion should be carefully constructed. The criterion should be based on the radiological quality of the waters in the immediate region of a specific repository, and it should be in terms of an acceptable potential increase in the radiological content of those waters due to the existence of the repository.

  12. Comparison of potential radiological consequences from a spent-fuel repository and natural uranium deposits

    International Nuclear Information System (INIS)

    Wick, O.J.; Cloninger, M.O.

    1980-09-01

    A general criterion has been suggested for deep geological repositories containing spent fuel - the repositories should impose no greater radiological risk than due to naturally occurring uranium deposits. The following analysis investigates the rationale of that suggestion and determines whether current expectations of spent-fuel repository performance are consistent with such a criterion. In this study, reference spent-fuel repositories were compared to natural uranium-ore deposits. Comparisons were based on intrinsic characteristics, such as radionuclide inventory, depth, proximity to aquifers, and regional distribution, and actual and potential radiological consequences that are now occurring from some ore deposits and that may eventually occur from repositories and other ore deposits. The comparison results show that the repositories are quite comparable to the natural ore deposits and, in some cases, present less radiological hazard than their natural counterparts. On the basis of the first comparison, placing spent fuel in a deep geologic repository apparently reduces the hazard from natural radioactive materials occurring in the earth's crust by locating the waste in impermeable strata without access to oxidizing conditions. On the basis of the second comparison, a repository constructed within reasonable constraints presents no greater hazard than a large ore deposit. It is recommended that if the naturally radioactive environment is to be used as a basis for a criterion regarding repositories, then this criterion should be carefully constructed. The criterion should be based on the radiological quality of the waters in the immediate region of a specific repository, and it should be in terms of an acceptable potential increase in the radiological content of those waters due to the existence of the repository

  13. The Olympic Dam copper-uranium-gold deposit, Roxby Downs, South Australia

    International Nuclear Information System (INIS)

    Roberts, D.E.; Hudson, G.R.T.

    1983-01-01

    The Olympic Dam copper-uranium-gold deposit appears to be a new type of strata-bound sediment-hosted ore deposit. It is located 650 km north-northwest of Adelaide in South Australia and was discovered in 1975. It has an areal extent exceeding 20 km 2 with vertical thicknesses of mineralization up to 350 m. The deposit is estimated to contain in excess of 2,000 million metric tons of mineralized material with an average grade of 1.6 percent copper, 0.06 percent uranium oxide, and 0.6 g/metric ton gold. The deposit occurs in the basement beneath 350 m of unmineralized, flat-lying Adelaidean (late Proterozoic) to Cambrian sediments in the Stuart shelf region of South Australia. The host rocks of the deposit are unmetamorphosed and are probably younger than 1,580 m.y. The deposit is spatially related to coincident gravity and magnetic anomalies and the intersection of west-northwest- and north-northwest-trending lineaments. The Proterozoic sediments comprising the local basement sequence are predominantly sedimentary breccias ranging from matrix-poor granite breccias to matrix-rich polymict breccias containing clasts of a variety of rock types. This sequence is over 1 km thick and has been divided into two main units--the Olympic Dam Formation and the Greenfield Formation. The Olympic Dam Formation has five members, three of which are matrix rich. The Greenfield Formation has three members, the lower two being very hematite rich while the upper has a significant volcanic component. Pervasive hematite, chlorite, and sericite alteration of varying intensity affects all the basement sequence

  14. Questions about uranium deposit distributions from geological GIS; Questionnements sur la distribution des gites d'uranium a partir des SIG geologiques

    Energy Technology Data Exchange (ETDEWEB)

    Milesi, J.P.; Brisset, F.; Lescuyer, J.L.; Stein, G.; Leistel, J.M. [AREVA, BU Mines, Tour Areva, 92 - Paris La Defense (France)

    2009-07-01

    The authors raised some questions about the use of GIS (geographic information system) and databases to compare metalliferous provinces and eras. These questions deal with the possibility of characterisation of a province signature from geological contexts or mineral associations, with the possibility to identify news zones of interest in a not well known area which may contain conventional uranium-bearing deposits, and with the possibility to characterise new types of deposits by a blind, data-driven or algebraic approach

  15. Uranium

    International Nuclear Information System (INIS)

    Whillans, R.T.

    1981-01-01

    Events in the Canadian uranium industry during 1980 are reviewed. Mine and mill expansions and exploration activity are described, as well as changes in governmental policy. Although demand for uranium is weak at the moment, the industry feels optimistic about the future. (LL)

  16. The sedimentology and uranium mineralisation of the Matjieskloof (GT7) deposit, Fraserburg district

    International Nuclear Information System (INIS)

    Le Roux, J.P.

    1982-08-01

    A sedimentological investigation was carried out on the Matjieskloof prospect of JCI, 40 km south of Fraserburg at the foot of the Teekloof pass. The deposit is located in a thick, tabular sandstone forming part of the Poortjie Member at the base of the Teekloof Formation. A study of sedimentary structures, grain sizes and palaeocurrents in the sandstone sequence at Matjieskloof suggests a general decrease in energy conditions upward in the succession, indicating denudation of the source areas to the south-west. The depositional environment of the mineralised S1-sandstone as revealed by field work and borehole analysis, is that of a low-sinuosity, braided river of the Bijou Creek type, deposited during ephemeral flash floods in a semi-arid environment. Three main flow systems are revealed by the palaeocurrent analysis, showing good correspondence with the reconstructed palaeoriver system. In the areas where these flow systems cross, scouring of the S2-sandstone into the underlying S1-sandstone occured. These regions also correspond to the confluence areas of channels within the braided river system, and apparently formed favourable environments for uranium mineralisation. This may be due to the presence of erosion surfaces within these areas, the increased thickness of sandstones and the accumulation of plant material, controlled by current velocities. Molybdenum shows a similar distribution to the uranium mineralisation, and both are clearly controlled by the sedimentological sub-environments

  17. Natural Radioactivity in Soil and Water from Likuyu Village in the Neighborhood of Mkuju Uranium Deposit

    Directory of Open Access Journals (Sweden)

    Najat K. Mohammed

    2013-01-01

    Full Text Available The discovery of high concentration uranium deposit at Mkuju, southern part of Tanzania, has brought concern about the levels of natural radioactivity at villages in the neighborhood of the deposit. This study determined the radioactivity levels of 30 soil samples and 20 water samples from Likuyu village which is 54 km east of the uranium deposit. The concentrations of the natural radionuclides 238U, 232Th, and 40K were determined using low level gamma spectrometry of the Tanzania Atomic Energy Commission (TAEC Laboratory in Arusha. The average radioactivity concentrations obtained in soil samples for 238U (51.7 Bq/kg, 232Th (36.4 Bq/kg, and 40K (564.3 Bq/kg were higher than the worldwide average concentrations value of these radionuclides reported by UNSCEAR, 2000. The average activity concentration value of 238U (2.35 Bq/L and 232Th (1.85 Bq/L in water samples was similar and comparable to their mean concentrations in the control sample collected from Nduluma River in Arusha.

  18. Uranium

    International Nuclear Information System (INIS)

    Batley, G.C.; McKay, A.D.

    1986-01-01

    Production of uranium oxide in Australia for 1983 was 3786 t(3211 t U). Uranium exports for 1983 were 3273 t U 3 O 8 at an average f.o.b. value of $41.02/lb U 3 O 8 . Private exploration expenditure for uranium in Australia during the 1982-83 fiscal year was $36.5 million, 35% less than in 1981-82. In November 1983, the Government decided that uranium mining would be allowed only at the existing Ranger and Nabarlek mines and at the proposed Olympic Dam mine. Australia's Reasonably Assured Resources of uranium recoverable at less than US$80/kg U as at December 1983, totalled 474 000 t U. Australia's total now represents 30% of the Western world's low-cost RAR. In addition Australia has 235 000 t U in the low-cost Estimated Additional Resources Category 1, which represents 31% of the Western world's resources in this category

  19. Study of low-grade uranium resources of the Coso formation, Owens Valley, California

    International Nuclear Information System (INIS)

    1975-08-01

    The Tertiary Coso Formation is exposed along the northern and western flanks of the Coso Range on the east side of Owens Valley, Inyo County, California. The surficial uranium deposits in the Coso Formation are found in the lower fanglomerate sequence. The yellow-gray fanglomerate has the best uranium potential of the various units. The overlying reddish-brown fanglomerate contains uranium deposits of limited lateral extent concentrated around the crests of granite knobs and inliers. The upper Coso lake-bed sequence consists of yellow-brown beds and light-gray beds, which interfinger with lenses of volcaniclastic rocks and are separated by a persistent stratum of rhyolitic tuff. Radiometry and analyses indicate a low uranium background in the granites. Field relations suggest that the impervious interface with the Coso sequence probably confined most mineral-bearing ground-water solutions to the overlying rocks. The principal surficial uranium deposits are found in the yellow-gray fanglomerate and reddish-brown fanglomerate in the lower Coso sequence and in the light-gray beds of the upper Coso Formation. The frequency distribution of uranium in the Coso Formation and underlying granite indicates that the granite is probably not a major source of uranium in the Coso strata

  20. Age of uranium ores at Ranger and Jabiluka unconformity vein deposits, Northern Territory, Australia

    International Nuclear Information System (INIS)

    Ludwig, K.R.; Grauch, R.I.; Nutt, C.J.; Frishman, D.; Nash, J.T.; Simmons, K.R.

    1985-01-01

    The Ranger and Jabiluka uranium deposits are the largest in the Alligator Rivers Uranium Field (ARUF), which contains at least 20% of the world's low-cost uranium reserves. Ore occurs in early Proterozoic metasediments, below an unconformity with sandstones of the 1.65 Ga Kombolgie Formation. This study uses U-Pb isotope data from over 60 whole-rock drill core samples that contained a variety of mineral assemblages and textures. Data for Ranger samples indicate a well-defined age of 1.74 +/-.02 Ga. This 1.74 Ga age is distinctly pre-Kombolgie, so the Ranger deposit cannot have been formed by processes requiring its presence. This Ranger age is consistent, however, with mineralization related to heating associated with either the emplacement of early post-metamorphic granites, or possibly with intrusion of the nearby Oenpelli Dolerite. In contrast, data for the least-altered Jabiluka ores yield a concordia-intercept age of 1.44 +/-.02 Ga--significantly younger than the Ranger age, and also younger than the Komobolgie. This age may correspond to a regional thermal event, as indicated both by mafic dikes of roughly this age and a zircon lower-intercept age from a nearby granite-gneiss. Thus, together with the well-defined ∼900 Ma age of ores at the Nabarlek deposit, there are at least 3 distinct periods of major U-mineralization in the ARUF. Data for both Ranger and Jabiluka indicate the same, profound isotopic disturbance at some time in the interval of 0.4-0.6 Ga. Possibly this time corresponds to the development of basins and associated basalt flows to the W and SW, a suggested by Crick et. al. (1980)

  1. Geological characteristics and prospecting potential of sandstone-type uranium deposits in the north margin of Qaidam basin

    International Nuclear Information System (INIS)

    Liu Lin; Song Xiansheng; Feng Wei

    2012-01-01

    The north margin of Qaidam Basin is composed with rift trough and Oulongbuluke landmass which is clamped by Qilian Mountain and Qaidam block Suture zone. The two activities provide a rich source of uranium for the basin area. The coal-bearing rocks as stratums of medium and lower Jurassic, is the main exploration target zones of sandstone-type uranium ore. Through geological survey and drilling, we think that the interlayer oxidation zone. being primary factors of sandstone-type uranium, can be divided into ancient type and modern type. The ancient interlayer oxidation zone type uranium deposit is the main prospecting types in the north margin of Qaidam Basin. Combined with analysis on geological conditions of sandstone-type uranium mineralization, we propose that eastern edge of Yuqia, southern edge of Lucao Mountain, Beidatan and northwest edge of Ulan depression are good prospects. (authors)

  2. Studies on methods and techniques of weak information extraction and integrated evaluation for sandstone-type uranium deposits

    International Nuclear Information System (INIS)

    Han Shaoyang; Ke Dan; Hou Huiqun; Hu Shuiqing

    2004-01-01

    Weak information extraction and integrated evaluation for sandstone-type uranium deposits are currently one of the important research contents in uranium exploration. Through several years researches, the authors put forward the meaning of aeromagnetic and aeroradioactive weak information extraction, study the formation theories of aeromagnetic and aeroradioactive weak information and establish effective mathematic models for weak information extraction. Based on GIS software, models of weak information extraction are actualized and the expert-grading model for integrated evaluation is developed. The trial of aeromagnetic and aeroradioactive weak information and integrated evaluation of uranium resources are completed by using GIS software in the study area. The researchful results prove that techniques of weak information extraction and integrated evaluation may further delineate the prospective areas of sandstone-type uranium deposits rapidly and improve the predicitive precision. (authors)

  3. Characterization of organic matter associated with uranium deposits in the Francevillian formation of Gabon (Lower Proterozoic)

    International Nuclear Information System (INIS)

    Cortial, F.; Gauthier-Lafaye, F.; Weber, F.; Oberlin, A.

    1990-01-01

    Elemental analysis, organic petrography, and high-resolution transmission electron microscopy were used to study organic matter in Lower Proterozoic rocks of the Francevillian Series in Africa. Results show a convincing relationship between solid bitumens derived from thermal alteration of crude oil, and deposition of uraninite ores. Evidence is presented that suggests the presence of migration paths for crude oil in associated sandstones. Moreover, the solid bitumens appear to have been further altered by radiation damage as a consequence of oxidation and uranium mineralization. (author)

  4. Regular distribution of gamma-anomalies within argillized rocks in fluorite-molybdenum-uranium deposit

    International Nuclear Information System (INIS)

    Korsakov, A.K.

    1983-01-01

    Connection between anomalous gamma-field and argillized rocks in uranium deposit has been considered. Quantitative evaluation of this relationships is realized statistically using intensity indices of argillization process and gamma-field anomaly. Analysis of maps for a number of horizontal masses has shown the anomalous gamma-field to be localized in the contour of argillizite rocks, the highest values of gamma-field anomaly being confined to the central parts of modified rocks aureoles. It has been established that enclosing rocks with intensity index of metasomatic process (argillization) from 50 to 70% are the most favourable ones for the localization of anomalous gamma-field

  5. Research progress on structural ore-controlling of Xinjiang Baiyanghe uranium-polymetallic deposit

    International Nuclear Information System (INIS)

    Wang Mou; Wang Guo; Zhang Xiaojun

    2014-01-01

    This article mainly starts from the tectonics of Baiyanghe uranium-polymetallic deposit, which control the ore-mineralization distribution. Elaborate the research progress by analysising the characteristics and divising the stage of ore-controlling structures. which divided into contact zone structure and fracture structure, including complex contact zone and extensional double tectonic superimposition which control the output of main ore-body. According to the tectonic activities order. the ore-controlling structure can be mainly divided into three stage activities, metallogenic before, mineralization and metallogenic period after. (authors)

  6. An review on geology study of carbonaceous-siliceous-pelitic rock type uranium deposit in China and the strategy for its development

    International Nuclear Information System (INIS)

    Zhao Fengmin

    2009-01-01

    Carbonaceous-siliceous-pelitic rock type uranium deposit was founded by Chinese uranium geologist, it refers to the uranium deposit hosted by non or light metamophosed carbonate,siliceous rock, pelitic rock and their intermediates. It is one of the important types uranium deposit in China. A lot of this type deposits have been discovered in China and their temporal-spatial distribution pattern and mineralization features have been basically identified, and the rich experience have layed a good foundation for the future exploration. Although the ore of this type is not favourable economically, it is still available. Because carbonaceous-siliceous-pelitic rock type uranium deposit has great resource potential, metallogenic study and exploration efforts should be projected differentially according to their economic profit so as to meet the uranium resource demand of nuclear power development in China. (authors)

  7. Mantle fluid metallogeny of granite-type uranium deposits in northern Guangdong

    International Nuclear Information System (INIS)

    Shen Weihou; Ling Hongfei; Sun Tao; Deng Ping; Zhu Ba; Huang Guolong' Tan Zhengzhong

    2010-01-01

    Both Guidong and Zhuguang composites in northern Guangdong Province consist of Indosinian and Yanshanian granite bodies. The two most well-known granite-type uranium ore fields in China, Xiazhuang and Changjiang, are located in the eastern parts of the the two composites, respectively. Studies on H, O, C, Pb, Sr, and Nd isotopes of uranium deposits Xiwang, Shituling and Xianshi within the Xiazhuang ore field and deposit Mianhuakeng within the Changjiang ore field showed that ore-forming fluid had D H 2 O of -97∼-4.1% and δ 18 O H 2 O of 8.1∼0.06%; post-ore fluid had δD H 2 O of -71∼-5% and δD H 2 O of 2.0∼-0.94%. After being compared with various fluids, these data suggested the ore-forming fluids were mainly composed of mantle fluid, whereas in the post-mineralization fluids, addition of fluids with meteoric water origin became evident or even dominant. Calcites from ore veins had δ 13 C of -9.2∼-0.31%, indicating mantle origin of ΣCO 2 . Studies of Pb, Sr and Nd isotopes revealed that ore-forming materials were a mixture of metal elements coming from granites, mafic dikes and basement metamorphic rocks. Mantle fluid metallogeny of these uranium deposits was compatible with the following geological facts. The deposits in Xiazhuang and Changjiang ore fields fell into super large ones. Within the ore fields, there were many mafic dikes of various groups and strike directions. Fault-depression basins were developed outside the granite composites. The timing and space of ore formation were closely related to the extension tectonic event (or emplacement of mafic dikes. The ore components were characterized by multiple origins. Both permissively and zoned distributions of alkaline alterations were strong and the mineralization fluids were originated from the mantle. The mineralization model could be described as follows: Fluids from Dehydration and degassing of subducting slabs in the late Mesozoic altered the mantle in the mantle wedge by metasomatism to

  8. A uranium-bearing coalificated wood remain from the Upper Carboniferous uranium ore deposit in the Baden-Baden region of the Black Forest

    International Nuclear Information System (INIS)

    Kirchheimer, F.

    1981-01-01

    From the 1973 discovered Upper Carboniferous uranium ore sandstone deposit in the Baden-Baden region (Black Forest) a uranium-bearing coalificated wood remain derived, probably the relic of a Cordaites-trunk. The chemical determinated whole uranium content of this amounts about to 40 wght.-%. Pitchblende of the collomorphic type is embedded in the vitrinite of the fossil and imitates the nearly destroyed former wood-structure. The aggregates of this mineral, surrounded by zones of contact, consist of at least two modifications of different reflectance and hardness. Radiometric analyses reveale a different disturbed radioactive equilibrium, which indicated partly loss and re-enrichment of the uranium-content in recent time. A part of the fossil is completely mineralized by pitchblende of high reflectance and associated galena. For this paragenesis the radiometric investigations proved an approached equilibrium of radioactive substances. Therefore it is to be estimated, that the pitchblende is not alterated substantially, in contrast to the embeddings in the vitrinite, rich in little reflecting and soft nasturanium. The inhomogenic mineralization of the highly coalificated fossil, also to recognise microscopically, is set in relation to the controverse genetic interpretation of the deposit. Final remarks are concerned to other uranium-enriched fossils, especially remains of bones of different origin and age. (orig.) [de

  9. The clearance of uranium after deposition of the nitrate and bicarbonate in different regions of the rat lung

    International Nuclear Information System (INIS)

    Ellender, M.

    1987-01-01

    This study investigated the tissue distribution and excretion of uranium after its deposition as either the nitrate or bicarbonate in the three regions of the respiratory system of the rat. Results confirm the recommendations of ICRP that uranyl nitrate and bicarbonate should be treated as class D compounds; but imply that some of the parameters used in the ICRP lung model are not applicable to soluble uranium compounds. (author)

  10. Methods of mineral potential assessment of uranium deposits: A mineral systems approach

    International Nuclear Information System (INIS)

    Jaireth, S.

    2014-01-01

    Mineral potential represents the likelihood (probability) that an economic mineral deposit could have formed in an area. Mineral potential assessment and prospectivity analysis use a probabilistic concepts to mineral deposits, where the probability of an event (formation of a mineral deposit) is conditional on two factors : i) geological processes occurring in the area, and ii) the presence of geological features indicative of those process. For instance, one of the geological processes critical for the formation of sandstone-hosted uranium deposits in an area is transport of uranium in groundwaters. Geological features indicative of this process in an area comprise, i) presence of leachable source rocks of uranium; ii) presence of highly permeable sandstone; and iii) suitable hydrogeological gradient driving flow groundwaters. Mineral deposits can also be conceptualised as mineral systems with more emphasis on mineralising processes. This concept has some clear parallels with the petroleum systems approach which has proven to be a useful in oil and gas exploration. Mineral systems are defined as ‘all geological factors that control the generation and preservation of mineral deposits’. Seven important geological factors are outlined to define the characteristics of a hydrothermal mineral system. These factors include: i) source of the mineralising fluids and transporting legends; ii) source of metals and other ore components; iii) migration pathways which may include inflow as well as outflow zones; iv) thermal gradients; v) source of energy to mobilised fluids; vi) mechanical and structural focusing mechanism at the trap site; and vii) chemical and/or physical cause for precipitation of ore minerals at the trap site. This approach, commonly known as the ‘source’, ‘transport’ and ‘trap’ paradigm has been redefined to introduce five questions as a basis to understand spatial and temporal evolution of a mineral system at all scales (regional to

  11. Episyenites and perspectives of occurrence of intergranite uranium deposits in the Karkonosze massif

    International Nuclear Information System (INIS)

    Lis, J.; Sylwestrzak, H.

    1979-01-01

    The Karkonosze granite massif (Lower Silesia) is one of the best-known massifs petrographically and tectonically. Detailed sampling revealed the presence of rocks which - with their granite structure - are characterized by the lack of quartz and marked porosity, or the presence of secondary quartz of specific milky colour. These rocks form small, irregular bodies occurring within normal granite. These bodies are clearly younger than the granite since, in some places, they were also formed from aplites cutting the granite. The mineral and chemical composition, the mode of occurrence and conditions of origin of these rocks resemble those of episyenites (that is rocks with syenite composition but formed from normal granite in result of subsequent alterations) from the Central Massif and Vendee areas of France. Three types of episyenites were differentiated: potassium-sodium, potassium and sodium. It was found out that in the Karkonosze area the mineralization points where already in the last century uranium minerals were recorded are connected with episyenites. The presence of episyenites and earlier detected presence of uraninite microgrowths point to the existence of marked analogy between Karkonosze granite and uranium-bearing granite massifs in France, thus indicating the possibility of occurrence of intragranite uranium deposits in the Karkonosze massif. (author)

  12. Study on a Salt Evaporation of the Uranium Deposits from an Electro-refiner

    International Nuclear Information System (INIS)

    Sung Bin Park; Dong Wook Cho; Gyu Hwan Oh; Jong Hyeon Lee; Sung Chan Hwang; Young Ho Kang; Han Soo Lee; Eung Ho Kim; Seong Won Park

    2008-01-01

    Uranium metal is electrodeposited onto a solid cathode during the electrorefining process. Uranium deposits from an electro-refiner contain about 30∼40 wt% salts. In order to recover pure uranium and transform it into metal ingots, the salts have to be removed. A salt distiller is adapted for a salt evaporation. A batch operation for the salt removal is carried out by a heating and vacuum evaporation. It is operated at 700 ∼ 1000 deg. C and less than 1 Torr, respectively. The behaviors of the salt evaporations were investigated by focusing on the effects of the vacuum pressure and the holding temperature on the salt distillation. The salt removal efficiencies were obtained with regards to the operational conditions. The Hertz-Langmuir relation was applied to the experimental results of the salt evaporations. The effective evaporation coefficients of the relation were obtained with regards to the operational conditions. The lower the vacuum pressure and the higher the holding temperature were, the higher the removal efficiencies of the salts were. (authors)

  13. An analysis of prominent prospect of in-situ sandstone type uranium deposits in Yanji basins group, Jilin province

    International Nuclear Information System (INIS)

    Peng Zhidong; Zhang Shuyi

    2003-01-01

    In Mesozoic-Cenozoic era, many medium-small-sized sedimentary basins had been formed in Yanbian draped-faulted region of Jilin Province. The basement of these basins is constituted of U-riched granite body produced during late Hercynian-early Yanshan period. Uranium-mineralization has been found in coal-bearing formation, oil-bearing formation and in tint layer of red formation. On the bases of analyzing of uranium source, geologic tectonic, paleoclimatology, paleogeography, hydrogeology and reconstruction, it is concluded that there is a prominent prospect to discover large in-situ sandstone-type uranium deposits in Yanji basins. (authors)

  14. Origin of the Okrouhlá Radouň episyenite-hosted uranium deposit, Bohemian Massif, Czech Republic: fluid inclusion and stable isotope constraints

    Science.gov (United States)

    Dolníček, Zdeněk; René, Miloš; Hermannová, Sylvie; Prochaska, Walter

    2014-04-01

    The Okrouhlá Radouň shear zone hosted uranium deposit is developed along the contact of Variscan granites and high-grade metasedimentary rocks of the Moldanubian Zone of the Bohemian Massif. The pre-ore pervasive alteration of wall rocks is characterized by chloritization of mafic minerals, followed by albitization of feldspars and dissolution of quartz giving rise to episyenites. The subsequent fluid circulation led to precipitation of disseminated uraninite and coffinite, and later on, post-ore quartz and carbonate mineralization containing base metal sulfides. The fluid inclusion and stable isotope data suggest low homogenization temperatures (˜50-140 °C during pre-ore albitization and post-ore carbonatization, up to 230 °C during pre-ore chloritization), variable fluid salinities (0-25 wt.% NaCl eq.), low fluid δ18O values (-10 to +2 ‰ V-SMOW), low fluid δ13C values (-9 to -15 ‰ V-PDB), and highly variable ionic composition of the aqueous fluids (especially Na/Ca, Br/Cl, I/Cl, SO4/Cl, NO3/Cl ratios). The available data suggest participation of three fluid endmembers of primarily surficial origin during alteration and mineralization at the deposit: (1) local meteoric water, (2) Na-Ca-Cl basinal brines or shield brines, (3) SO4-NO3-Cl-(H)CO3 playa-like fluids. Pre-ore albitization was caused by circulation of alkaline, oxidized, and Na-rich playa fluids, whereas basinal/shield brines and meteoric water were more important during the post-ore stage of alteration.

  15. The relationship of carbonate-siliceous-pelitic uranium deposits with the plunging portions of down-faulted zones

    International Nuclear Information System (INIS)

    Liu Guihua; Liu Shouzhi; Zhou Huawen.

    1985-01-01

    Five uranium deposits of carbonate-siliceous-pelitic type occurred in different geological setting are studied. The geological data suggest that this type of uranium deposits is mostly located in the plunging portions of down-faulted zones. The cause of this kind of occurrence is tentatively discussed. It is proposed that uraniferous strata are the uranium source in deposits. The infiltration under arid climatic conditions promoted the uranium concentration up to ore grade. The mesozoic-cenozoic era which is characterized by the arid climate was the main ore-forming period. The converging condition of ground water in the plunging portions of down-faulted zones was better. Therefore, the plunging portions of down-faulted zones were more favourable for uranium ore formation compared with that of the uplifting portions. The preservation is the most important ore-controlling factor under the neotectonic movement and the plunging portions are the most favourable in this sence. The recognition criteria for the plunging portions of down-faulted zones which can be used in uranium exploration are proposed

  16. The distribution of E-centres concentration in the minerals of the wall-rocks of uranium deposit

    International Nuclear Information System (INIS)

    Kislyakov, Ya.M.; Moiseev, B.M.; Rakov, L.T.; Kulagin, Eh.G.

    1975-01-01

    Electron paramagnetic resonance was used to investigate the distribution of electron-hole centres caused by natural radioactive irradiation in terrigenous arcosic rocks and their principal mineral components (quartz-feldspar concretions, white and smoky quartz, feldspars). The relationship between concentrations of E-centres and the uranium content of the rocks reflects the genetic features of the uranium mineralization. Taking one specific deposit as an example, the author shows the proportional dependence between uranium content and E-centre concentration. The dependence reflects the practically simultraneous formation of the main mass of epigenetic mineralization. The hypothesis that older (syngenetic) ore deposits may have existed was not confirmed. Despite the long interval between sedimentary accumulation end epigenesis, no significant surplus concentrations of E-centres were found in epigenetic-metamorphic rocks. Anomalous concentrations of uranium and E-centres are caused by uranium migration during later epigenetic processes superimposed on the mesozoic ore-controlling zonality. One result of this migration is the formation in limonitized rocks of ''augen'' ores for which low concentrations of paramagnetic centres are typical. For the study of the distribution of E-centres in rocks from uranium deposits, it is possible to use polymineral mixtures. For the proper interpratation of the data obtained, however, account must be taken of the sensitivity to irradiation of the various mineral components, particularly the various forms of quartz, which is the principal natural dosimeter. (E.G.)

  17. Migration behavior of naturally occurring radionuclides at the Nopal I uranium deposit, Chihuahua, Mexico

    Science.gov (United States)

    Prikryl, James D.; Pickett, David A.; Murphy, William M.; Pearcy, English C.

    1997-04-01

    Oxidation of pyrite at the Nopal I uranium deposit, Peña Blanca district, Chihuahua, Mexico has resulted in the formation of Fe-oxides/hydroxides. Anomalous U concentrations (i.e. several hundred to several thousand ppm) measured in goethite, hematite, and amorphous Fe-oxyhydroxides in a major fracture that crosscuts the deposit and the absence of U minerals in the fracture suggest that U was retained during secondary mineral growth or sorbed on mineral surfaces. Mobilization and transport of U away from the deposit is suggested by decreasing U concentrations in fracture-infilling materials and in goethite and hematite with distance from the deposit. Greater than unity {234U}/{238U} activity ratios measured in fracture-infilling materials indicate relatively recent ( < 1 Ma) U uptake from fluids that carried excess 234U. Systematic decreases in {234U}/{238U} activity ratios of fracture materials with distance from the deposit suggest a multistage mobilization process, such as remobilization of U from 234U-enriched infill minerals or differential or diminished transport of U-bearing solutions containing excess 234U.

  18. Forecasting sandstone uranium deposits in oil-and-gas bearing basins

    International Nuclear Information System (INIS)

    Pechenkin, I.

    2014-01-01

    The interrelation between oxidation and reduction processes in the carbonaceous strata of Paleogene age was first studied in the 1950s in deposit of the Fergana depression. The presence of pre-ore and post-ore epigenesis of petroleum series was established. Part of uranium mineralization was found to be covered with fluid oil. In the middle of the 1960s in the Sabirsay deposit (Uzbekistan) in primary red-coloured continental sediment of Cretaceous age were studied pre-ore reduction changes, which caused economic uranium mineralization in contrasting geochemical barrier. Further research showed that multidirectional epigenetic processes had changed repeatedly. Later, in the 1970s, American geologists studying uranium deposits in the oil-and-gas bearing Texas Plain reached similar conclusions. From their point of view, in the Benevides deposit the main zones of mineralization tend to be located near the boundary where the zones of oxidation in the strata wedge in, developing in epigenetically reduced formations. A second post-mineral reduction was registered in a number of rock bodies. The complexity of the processes is determined by the double role of hydrocarbon fluids and the products of their dissolution. On the one hand, bituminization of permeable strata as well as pyritization, chloritization, dolomitization and other alterations associated with it create favourable geochemical conditions of a reducing character for a subsequent concentration of ore and nonmetal raw materials. On the other hand, intrusion of bitumen and its dissolution in the aeration zone leads to the burial of the mineralization which formed earlier and disappearance of all traces of its formation (epigenetic oxidation zoning). Thus forecasting and subsequent prospecting become impeded. The established sequence of epigenetic alterations allows us to carry out specialized mapping in productive regions, uncovering hidden parts of epigenetic oxidation zoning and “buried” mineralization

  19. The outlook on potential uranium ISL Mining at Nyota Deposit (Tanzania)

    International Nuclear Information System (INIS)

    Boytsov, A.; Martynenko, V.; Stander, S.

    2014-01-01

    The Nyota Deposit, located in the Karoo sedimentary basin in south-western Tanzania, is currently the subject of a detailed feasibility study by the Uranium One subsidiary, Mantra Tanzania. The Nyota deposit has JORC compliant resources of 152 Mlbs of U 3 O 8 (at a 100 ppm cut-off) [~58,500 tU and ~85 ppm U], at an average grade of 286 ppm [~243 ppmU]. The original mining and extraction philosophy was based around an open cast mining operation, and a conventional IX, resin in pulp processing plant, producing up to 7 Mlb of U 3 O 8 [~2,700 tU] per year over life of mine of 11 years. With their extensive ISL experience worldwide, Uranium One recognised that an opportunity might exists to convert a larger portion of the resource to reserves by extending the extraction options to include ISL. Preliminary work done in 2012 on the water table and mineral resource revealed that approximately one third of the resource (up to 50 Mlbs U 3 O 8 ) [~19,000 tU] both within and outside the current pit designs, are situated in permeable sediments below the groundwater level and potentially amenable to ISL.

  20. Wall rock alteration and geochemical characteristics of Hengjian-Gangshangying uranium deposit in Xiangshan, Jiangxi

    International Nuclear Information System (INIS)

    Wu Yu; Pan Jiayong; Xia Fei; Liu Guoqi

    2013-01-01

    With the method of thin section identification, electron probe and the petrochemical analysis, wall rock alteration and geochemical characteristics was studied for Hengjian-Gangshangying uranium deposit in Xiangshan. The results show that the deposit has a variety of alteration, which include hydromicazation, albitization, chloritization, carbonation, fluoritization, pyritization, and silicification. The alteration can be easily divided in five zones petrochemically, the hosting rock (granite porphyry) are of quasi aluminium to peraluminous which is high in Si and alkali and low in calcium-magnesium. Major elements, trace elements and rare elements in the alteration rock show regular variations and the values of major elements Ca, Mn, K and incompatible elements Sr, Th, P, Y, Yb and HREE have been increased in mineralization process. Mo, W, Pb, Zn can be used as indicator elements for uranium mineralization. The alternated rock has the same geochemical characteristics as the ore-hosting rock body which can be proven by the consistent distribution patterns of trace elements and rare elements. The mineralization material bears the characteristics of deeply-derived source. (authors)

  1. The Itataia phosphate-uranium deposit (Ceará, Brazil) new petrographic, geochemistry and isotope studies

    Science.gov (United States)

    Veríssimo, César Ulisses Vieira; Santos, Roberto Ventura; Parente, Clóvis Vaz; Oliveira, Claudinei Gouveia de; Cavalcanti, José Adilson Dias; Nogueira Neto, José de Araújo

    2016-10-01

    The Itataia phosphate-uranium deposit is located in Santa Quitéria, in central Ceará State, northeastern Brazil. Mineralization has occurred in different stages and involves quartz leaching (episyenitization), brecciation and microcrystalline phase formation of concretionary apatite. The last constitutes the main mineral of Itatiaia uranium ore, namely collophane. Collophanite ore occurs in massive bodies, lenses, breccia zones, veins or episyenite in marble layers, calc-silicate rocks and gneisses of the Itataia Group. There are two accepted theories on the origin of the earliest mineralization phase of Itataia ore: syngenetic (primary) - where the ore is derived from a continental source and then deposited in marine and coastal environments; and epigenetic (secondary) - whereby the fluids are of magmatic, metamorphic and meteoric origin. The characterization of pre- or post-deformational mineralization is controversial, since the features of the ore are interpreted as deformation. This investigation conducted isotopic studies and chemical analyses of minerals in marbles and calc-silicate rocks of the Alcantil and Barrigas Formations (Itataia Group), as well as petrographic and structural studies. Analysis of the thin sections shows at least three phosphate mineral phases associated with uranium mineralizaton: (1) A prismatic fluorapatite phase associated with chess-board albite, arfvedsonite and ferro-eckermannite; (2) a second fluorapatite phase with fibrous radial or colloform habits that replaces calcium carbonate in marble, especially along fractures, with minerals such as quartz, chlorite and zeolite also identified in calc-silicate rocks; and (3) an younger phosphate phase of botryoidal apatite (fluorapatite and hydroxyapatite) related with clay minerals and probably others calcium and aluminum phosphates. Detailed isotopic analysis carried out perpendicularly to the mineralized levels and veins in the marble revealed significant variation in isotopic

  2. Application of soil radon survey to searching for sandstone-type uranium deposit at western margin of Ordos basin

    International Nuclear Information System (INIS)

    Liu Hanbin; Yin Jinshuang; Cui Yonghui

    2006-01-01

    On the basis of condition tests of soil radon survey at certain uranium deposit in Ordos basin, regional soil radon survey was carried but in a study area of western margin of Ordos basin. By processing of soil radon survey data, five anomalous areas with certain metallogenic potential have been delineated. Then, discovered anomalies have been interpreted and evaluated for providing important reference for further drilling work. Research results indicate that by soil radon survey, anomalies may be distinguished in a basin, and soil radon survey could be an important geochemical prospecting method for rapid evaluation of sandstone-type uranium deposit in basin areas. (authors)

  3. Geological and geochemical aspects of uranium deposits: a selected, annotated bibliography. Vol. 2, Rev. 1. [490 references

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J.M.; Brock, M.L.; Garland, P.A.; White, M.B.; Daniel, E.W. (comps.)

    1979-07-01

    This bibliography, a compilation of 490 references, is the second in a series compiled from the National Uranium Resource Evaluation (NURE) Bibliographic Data Base. This data base is one of six data bases created by the Ecological Sciences Information Center, Oak Ridge National Laboratory, for the Grand Junction Office of the Department of Energy. Major emphasis for this volume has been placed on uranium geology, encompassing deposition, genesis of ore deposits, and ore controls; and prospecting techniques, including geochemistry and aerial reconnaissance. The following indexes are provided to aid the user in locating references of interest: author, geographic location, quadrangle name, geoformational feature, taxonomic name, and keyword.

  4. Chemical vapor deposition (CVD) of uranium for alpha spectrometry; Deposicion quimica de vapor (CVD) de uranio para espectrometria alfa

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez V, M. L.; Rios M, C.; Ramirez O, J.; Davila R, J. I.; Mireles G, F., E-mail: luisalawliet@gmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2015-09-15

    The uranium determination through radiometric techniques as alpha spectrometry requires for its proper analysis, preparation methods of the source to analyze and procedures for the deposit of this on a surface or substrate. Given the characteristics of alpha particles (small penetration distance and great loss of energy during their journey or its interaction with the matter), is important to ensure that the prepared sources are thin, to avoid problems of self-absorption. The routine methods used for this are the cathodic electro deposition and the direct evaporation, among others. In this paper the use of technique of chemical vapor deposition (CVD) for the preparation of uranium sources is investigated; because by this, is possible to obtain thin films (much thinner than those resulting from electro deposition or evaporation) on a substrate and comprises reacting a precursor with a gas, which in turn serves as a carrier of the reaction products to achieve deposition. Preliminary results of the chemical vapor deposition of uranium are presented, synthesizing and using as precursor molecule the uranyl acetylacetonate, using oxygen as carrier gas for the deposition reaction on a glass substrate. The uranium films obtained were found suitable for alpha spectrometry. The variables taken into account were the precursor sublimation temperatures and deposition temperature, the reaction time and the type and flow of carrier gas. Of the investigated conditions, two depositions with encouraging results that can serve as reference for further work to improve the technique presented here were selected. Alpha spectra obtained for these depositions and the characterization of the representative samples by scanning electron microscopy and X-ray diffraction are also presented. (Author)

  5. Considerations and data on the uranium deposits in West-Mecsek Mountains, Hungary

    International Nuclear Information System (INIS)

    Erdi-Krausz, G.; Harsanyi, L.

    1999-01-01

    In 1987, the Government of Hungary closed the uranium mining in the Mecsek Mountain. Data are presented on the uranium reserves in the abandoned site of West-Mecsek. The history of uranium mining and the total amount of produced uranium are up to 31 December 1997 is presented. Some countries in Europe also abandon uranium mining, others develop it (Ukraine, Russia, Kazakhstan, Canada, Australia etc.). The Hungarian uranium reserves should be registered as a part of the national assets. (R.P.)

  6. Geochronology and Fluid-Rock Interaction Associated with the Nopal I Uranium Deposit, Pena Blanca, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    M. Fayek; P. Goodell; M. Ren; A. Simmons

    2005-07-11

    The Nopal I uranium (U) deposit, Pena Blanca District, Mexico, largely consists of secondary U{sup 6+} minerals, which occur within a breccia pipe mainly hosted by the 44 Ma Nopal and Colorados volcanic formations. These two units overly the Pozos conglomerate formation and Cretaceous limestone. Three new vertical diamond drill holes (DDHs) were recently drilled at Nopal I. DDH-PB1 with continuous core was drilled through the Nopal I deposit and two additional DDHs were drilled {approx}50 m on either side of the cored hole. These DDHs terminate 20 m below the current water table, thus allowing the detection of possible gradients in radionuclide contents resulting from transport from the overlying uranium deposit. Primary uraninite within the main ore body is rare and fine-grained ({approx}50 micrometers), thus making geochronology of the Nopal I deposit very difficult. Uranium, lead and oxygen isotopes can be used to study fluid-uraninite interaction, provided that the analyses are obtained on the micro-scale. Secondary ionization mass spectrometry (SIMS) permits in situ measurement of isotopic ratios with a spatial resolution on the scale of a few {micro}m. Preliminary U-Pb results show that uraninite from the main ore body gives an age of 32 {+-} 8 Ma, whereas uraninite from the uraniferous Pozos conglomerate that lies nearly 100 m below the main ore body and 25 meters above the water table, gives a U-Pb age that is <1 Ma. Oxygen isotopic analyses show that uraninite from the ore body has a {delta}{sup 18}O = -10.8{per_thousand}, whereas the uraninite within the Pozos conglomerate has a {delta}{sup 18}O = +1.5{per_thousand}. If it is assumed that both uraninites precipitated from meteoric water ({delta}{sup 18}O = -7{per_thousand}), then calculated precipitation temperatures are 55 C for the uraninite from the ore body and 20 C for uraninite hosted by the Pozos conglomerate. These temperatures are consistent with previous studies that calculated precipitation

  7. In situ bio-remediation of contaminated soil in a uranium deposit

    International Nuclear Information System (INIS)

    Groudev, St.; Spasova, I.; Nicolova, M.; Georgiev, P.

    2005-01-01

    The uranium deposit Curilo, located in Western Bulgaria, for a long period of time was a site of intensive mining activities including both the open-pit and underground techniques as well as in situ leaching of uranium. The mining operations were ended in 1990 but until now both the surface and ground waters and soils within and near the deposit are heavily polluted with radionuclides (mainly uranium and radium) and heavy metals (mainly copper, zinc and cadmium). Laboratory experiments carried out with soil samples from the deposit revealed that an efficient removal of the above-mentioned contaminants was achieved by their solubilizing and washing the soil profile by means of acidified water solutions. The solubilization was connected with the activity of the indigenous soil microflora, mainly with the activity of some acidophilic chemo-litho-trophic bacteria. It was possible to enhance considerably this activity by suitable changes in the levels of some essential environmental factors such as pH and water, oxygen and nutrient contents in the soil. Such treatment was successfully applied also under real field conditions in the deposit. The effluents from the soil profile during the operation above-mentioned contained the pollutants as well as other heavy metals such as iron and manganese dissolved from the soil in concentrations usually higher than the relevant permissible levels for waters intended for use in the agriculture and/or industry. For that reason, these effluents were efficiently cleaned up by means of a natural wetland located near the treated soil. However, such treatment as any other method for treatment of polluted waters is connected with additional costs which increase the total costs for the soil cleanup. A possible way to avoid or at least largely to facilitate the cleanup of the soil effluents is to apply a biotechnological method in which the soil contaminants solubilized in the upper soil layers (mainly in the horizon A) are transferred into

  8. Statistics and geostatistics: Kriging and use of hemivariogram functions in the structural investigation of uranium deposits

    International Nuclear Information System (INIS)

    Lucero Michaut, H.N.

    1980-01-01

    After presenting some general conceptual considerations regarding the theory of regionalized variables, the paper deals with specific applications of the intrinsic dispersion law to the determination, description and quantification of structures. It then briefly describes two uranium deposits in Cordoba province, the study of which yielded the basic data and parameters for compiling the geostatistical results presented. Before taking up the matter of structural interpretations, it refers briefly to the mathematical relationship between the number of sampling points available and the number of directions that can be investigated by the variogram method and also emphasizes the need for quantifying regionalization concepts on the basis of a table of absolute dimensionalities. In the case of the ''Rodolfo'' deposit it presents and comments on the hemivariograms for concentrations, thicknesses and accumulations, drawing attention at the same time to the existence of significant nest-like phenomena (gigogne structures). In this connection there is also a discussion of the case of iterative lenticular mineralization on a natural and a simulated model. The ''Schlagintweit'' deposit is dealt with in the same way, with descriptions and evaluations of the subjacent structures revealed by the hemivariographic analysis of grades, mineralization thicknesses and accumulations. This is followed by some considerations on the possibility of applying Krige and Matheron correctors in the moderation of anomalous mineralized thicknesses. In conclusion, the paper presents a ''range ellipse'' for grades; this is designed to supplement the grid of sampling points for the ''Rodolfo'' deposit by means of Matheronian kriging techniques. (author)

  9. Fluid flow and reactive mass transport modeling of reducing mechanisms in the formation of unconformity-related uranium deposits

    International Nuclear Information System (INIS)

    Yang, J.

    2014-01-01

    Unconformity-related uranium deposits in sedimentary basins represent the most important and profitable deposits among other types of uranium deposits, however their origin is still not fully understood. To better understand their formation, and in particular to address possible reducing mechanisms in the precipitation of uraninite, we develop a highly conceptualized 2-D model that fully couples fluid flow and heat transfer with reactive mass transport. We consider a series of numerical scenarios and examine the effect of graphite zone and Fe-rich silicates as the carbon-based and the inorganic-based reducing agents on the ore genesis. Our numerical results reveal that both the reducing mechanisms can lead to the precipitation of uraninite below the unconformity interface away from the faulted zone. Physiochemical parameters such as oxygen fugacity and temperature play a significant role in localization of the uraninite. Localization of these deposits is in relation to the decrease of oxygen fugacity, generally resulting from the interaction of oxidized uranium-bearing fluids with the reductants. Uraninites precipitate simultaneously with hematite in the areas experiencing reduction of oxygen fugacity and having a temperature of 180-200°C and a pH of 2.5- 4.5. Wide-spread alteration halos in the basement and around the uranium deposit include hematite, Mg-chlorite, and muscovite associated with minor amounts of pyrite and K-feldspar alteration. These results have important geological and exploration implications. (author)

  10. Investigation of the solubility of yellowcake in the lung of uranium mill yellowcake workers by assay for uranium in urine and in vivo photon measurements of internally deposited uranium compounds

    International Nuclear Information System (INIS)

    Spitz, H.B.; Robinson, B.; Fisher, D.R.; Heid, K.R.

    1980-01-01

    The solubility of yellowcake compounds in the lungs of uranium mill workers is investigated by examination of those yellowcake workers who risk a potential occupational exposure by virtue of their proximity to the material or by involvement in an acute inhalation exposure incident. An indication of inhalation exposure to a soluble uranium compound is the presence of uranium in a urine sample collected from the mill worker. Excreta samples are collected and analyzed and in vivo photon measurements are performed for several sequential days. The results are compared with earlier samples collected as part of the routine program at at the mill site. Uranium concentrations are determined using a standard fluorometric technique. In vivo scintillation measurements of 234 Th are performed as an adjunct to the urine assay for uranium. An essential part of the study is to establish a baseline value of chronic uranium inhalation exposure for the yellowcake worker. Broad criteria have been established to identify the acute exposure condition to initiate excreta collection from the exposed yellowcake worker. After an inhalation exposure incident, the presence of uranium in the urine of the worker can be compared with the baseline data to infer the solubility and transference of the yellowcake compound deposited in the lung. (H.K.)

  11. Geology and recognition criteria for sandstone uranium deposits in mixed fluvial-shallow marine sedimentary sequences, South Texas. Final report

    International Nuclear Information System (INIS)

    Adams, S.S.; Smith, R.B.

    1981-01-01

    Uranium deposits in the South Texas Uranium Region are classical roll-type deposits that formed at the margin of tongues of altered sandstone by the encroachment of oxidizing, uraniferous solutions into reduced aquifers containing pyrite and, in a few cases, carbonaceous plant material. Many of the uranium deposits in South Texas are dissimilar from the roll fronts of the Wyoming basins. The host sands for many of the deposits contain essentially no carbonaceous plant material, only abundant disseminated pyrite. Many of the deposits do not occur at the margin of altered (ferric oxide-bearing) sandstone tongues but rather occur entirely within reduced, pyurite-bearing sandstone. The abundance of pyrite within the sands probably reflects the introduction of H 2 S up along faults from hydrocarbon accumulations at depth. Such introductions before ore formation prepared the sands for roll-front development, whereas post-ore introductions produced re-reduction of portions of the altered tongue, leaving the deposit suspended in reduced sandstone. Evidence from three deposits suggests that ore formation was not accompanied by the introduction of significant amounts of H 2 S

  12. Geology and recognition criteria for sandstone uranium deposits in mixed fluvial-shallow marine sedimentary sequences, South Texas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Adams, S.S.; Smith, R.B.

    1981-01-01

    Uranium deposits in the South Texas Uranium Region are classical roll-type deposits that formed at the margin of tongues of altered sandstone by the encroachment of oxidizing, uraniferous solutions into reduced aquifers containing pyrite and, in a few cases, carbonaceous plant material. Many of the uranium deposits in South Texas are dissimilar from the roll fronts of the Wyoming basins. The host sands for many of the deposits contain essentially no carbonaceous plant material, only abundant disseminated pyrite. Many of the deposits do not occur at the margin of altered (ferric oxide-bearing) sandstone tongues but rather occur entirely within reduced, pyurite-bearing sandstone. The abundance of pyrite within the sands probably reflects the introduction of H/sub 2/S up along faults from hydrocarbon accumulations at depth. Such introductions before ore formation prepared the sands for roll-front development, whereas post-ore introductions produced re-reduction of portions of the altered tongue, leaving the deposit suspended in reduced sandstone. Evidence from three deposits suggests that ore formation was not accompanied by the introduction of significant amounts of H/sub 2/S.

  13. Uranium*

    Science.gov (United States)

    Grenthe, Ingmar; Drożdżyński, Janusz; Fujino, Takeo; Buck, Edgar C.; Albrecht-Schmitt, Thomas E.; Wolf, Stephen F.

    Uranium compounds have been used as colorants since Roman times (Caley, 1948). Uranium was discovered as a chemical element in a pitchblende specimen by Martin Heinrich Klaproth, who published the results of his work in 1789. Pitchblende is an impure uranium oxide, consisting partly of the most reduced oxide uraninite (UO2) and partly of U3O8. Earlier mineralogists had considered this mineral to be a complex oxide of iron and tungsten or of iron and zinc, but Klaproth showed by dissolving it partially in strong acid that the solutions yielded precipitates that were different from those of known elements. Therefore he concluded that it contained a new element (Mellor, 1932); he named it after the planet Uranus, which had been discovered in 1781 by William Herschel, who named it after the ancient Greek deity of the Heavens.

  14. The uranium ore deposits in Ciudad Rodrigo Phyllites. about the possibility of new deposits; Los yacimientos uraniferos en las pizarras paleozoicas de Ciudad Rodrigo. sobre la posible existencia de nuevas mineralizaciones

    Energy Technology Data Exchange (ETDEWEB)

    Mingarro Martin, E.; Marin Benavente, C.

    1969-07-01

    The main features of the genesis of uranium deposits of the Fe mine type, are discussed in this paper. Pitchblende ore is related with phyllites bearing organic material and with geomorphological level, fossilized by eocene sediments. As a result, new uranium ore deposits are possible under Ciudad Rodrigo tertiary basin, tertiary cover depth being little more than three hundred feet. (Author)

  15. Geochemical dispersion associated with uranium deposits in sandstone roll front type and its relationship to the Orinoco Oil Belt, Venezuela

    International Nuclear Information System (INIS)

    Manrique, J.

    2014-01-01

    In Venezuela, there is a potential for the formation of uranium deposits in areas such as the Guiana Shield, the south of the Eastern Basin, the Andes and the massif of Baúl, among other areas. Especially great interest is the exploration of uranium redox interface type (roll front), in areas such as the southern part of the Orinoco Oil Belt, north and northwest of the Guiana Shield, where groundwater uranium collecting the weathering shield flowing northward in the sandstones and mudstones of the Cretaceous to Quaternary formations, which constitute the southern boundary of the Eastern basin Venezuela. The presence of gas, extra-heavy crude oil, bitumen and lignite of the Orinoco Oil Belt can be an effective barrier for uranium in solution, which may have precipitated at the redox interface of this groundwater. This process certainly was more effective before the Orinoco river take its course to the east and the waters of small rivers and large draining shield contributed to uranium aquifers became more deep north. This work was based on a qualitative model describing geochemical dispersion associated with uranium deposits in sandstone, roll front type, which indicates that the daughter isotopes 238 U, which can migrate extensively are: 222 Rn, 4 He, and in a smaller proportion: 226 Ra and 222 Rn daughters ( 214 Bi, 210 Pb). The main exploration methods were established, which can be applied in areas of the Orinoco Oil Belt, north of the Guiana Shield, and areas west of this, among the most important are: soil measurements of radon and helium near faults, sampling soils with gamma spectrometry analysis, log interpretation of oil wells in the area of interest to establish gamma – lithological anomalies, ground water analysis of uranium, radon, radium, helium, vanadium, selenium, molybdenum, analysis of samples oil drilling cores to locate anomalous stratigraphic levels. This research will provide the basis to establish methodologies for uraniferous exploration

  16. Genetic and grade and tonnage models for sandstone-hosted roll-type uranium deposits, Texas Coastal Plain, USA

    Science.gov (United States)

    Hall, Susan M.; Mihalasky, Mark J.; Tureck, Kathleen; Hammarstrom, Jane M.; Hannon, Mark

    2017-01-01

    The coincidence of a number of geologic and climatic factors combined to create conditions favorable for the development of mineable concentrations of uranium hosted by Eocene through Pliocene sandstones in the Texas Coastal Plain. Here 254 uranium occurrences, including 169 deposits, 73 prospects, 6 showings and 4 anomalies, have been identified. About 80 million pounds of U3O8 have been produced and about 60 million pounds of identified producible U3O8 remain in place. The development of economic roll-type uranium deposits requires a source, large-scale transport of uranium in groundwater, and deposition in reducing zones within a sedimentary sequence. The weight of the evidence supports a source from thick sequences of volcanic ash and volcaniclastic sediment derived mostly from the Trans-Pecos volcanic field and Sierra Madre Occidental that lie west of the region. The thickest accumulations of source material were deposited and preserved south and west of the San Marcos arch in the Catahoula Formation. By the early Oligocene, a formerly uniformly subtropical climate along the Gulf Coast transitioned to a zoned climate in which the southwestern portion of Texas Coastal Plain was dry, and the eastern portion humid. The more arid climate in the southwestern area supported weathering of volcanic ash source rocks during pedogenesis and early diagenesis, concentration of uranium in groundwater and movement through host sediments. During the middle Tertiary Era, abundant clastic sediments were deposited in thick sequences by bed-load dominated fluvial systems in long-lived channel complexes that provided transmissive conduits favoring transport of uranium-rich groundwater. Groundwater transported uranium through permeable sandstones that were hydrologically connected with source rocks, commonly across formation boundaries driven by isostatic loading and eustatic sea level changes. Uranium roll fronts formed as a result of the interaction of uranium-rich groundwater

  17. Superposition of late albitites on the aureoles of near-ore argillization in one of uranium-molybdenum deposits

    International Nuclear Information System (INIS)

    Barsukov, V.L.; Pogudina, M.A.; Ryzhov, O.B.

    1981-01-01

    Late albitites superimposed on oreoles of near-ore argillization in a deposit of uranium-molybdenum formation are studied. Morphology of the superimposed albitites, confirming their late formation and superposition on oreoles of argillization, is described. Composition and crystal structure of the albitites are pointed out [ru

  18. Uraninite, coffinite and brannerite from shear-zone hosted uranium deposits of the Bohemian Massif (Central European Variscan belt)

    Czech Academy of Sciences Publication Activity Database

    René, Miloš; Dolníček, Z.

    2017-01-01

    Roč. 7, č. 4 (2017), č. článku 50. ISSN 2075-163X Institutional support: RVO:67985891 Keywords : uranium deposits * mineralogy * uraninite * coffinite * brannerite * Moldanubian Zone * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 2.088, year: 2016 http://www.mdpi.com/2075-163X/7/4/50

  19. Geostatistical ore reserve estimation for a roll-front type uranium deposit (practitioner's guide)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y.C.; Knudsen, H.P.

    1977-01-01

    This report comprises two parts. Part I contains illustrative examples of each phase of a geostatistical study using a roll-front type uranium deposit. Part II contains five computer programs and comprehensive users' manuals for these programs which are necessary to make a practical geostatistical study. (LK)

  20. Uranium deposits in the metamorphic basement of the Rouergue massif. Genesis and extension of related albitization processes

    International Nuclear Information System (INIS)

    Schmitt, J.M.

    1982-02-01

    Albitization processes in the Rouergue metamorphic basement, probably Permian aged is evidenced. Late development of uranium orebodies occured within albitized zones. The detection of the latter serves as a highly valuable indirect guide for prospecting this type of deposits in a metamorphic basement [fr

  1. Significance of special blasting modes for anti shock struggle at hydrothermal Pribram uranium ore deposit

    International Nuclear Information System (INIS)

    Stenczel, J.

    1988-01-01

    Situations are presented which occur in connection with blasting jobs. Special blasting operations are described. In the Pribram uranium deposit two types of special blasting operations were tested. Conditions are described under which softening blasting was carried out. This type of work did not prove satisfactory in operation and is therefore not performed at the Pribram deposit. A theoretical analysis is made of shock distrubance blasting and the procedure of designing such projects, the placement of explosives and the determination of their size. Such blasting jobs have been tested in shock zones of vein node. The total weight of the explosive was 100 to 200 kg of Px V 19. In most cases a mine shock was initiated (in some cases with a delay of up to several dozen hours). The said method increases the technical safety of operation. At the Pribram deposit it is only used in cases of utmost necessity because its use increases costs and delays the procedure of mining work. (E.S.). 9 figs., 1 tab., 6 refs

  2. The geochronology of uranium deposits in the Great Bear batholith, Northwest Territories

    International Nuclear Information System (INIS)

    Miller, R.G.

    1982-01-01

    The oldest uranium mineralisation found in the Great Bear batholith during this study may be hydrothermal pitchblende-hematite veins at Hottah Lake. Their apparent age of 2058 +- 34 Ma can also be explained by the contamination of deposits only 440 +- 57 Ma old, which is the age of pitchblende veins nearby. Numerous pendants of metamorphosed, uraninite-bearing 'black sand' placers in a north-trending belt west of the Wopmay Fault are 1860 +- 20 Ma old, the age of the granites that intrude them. Mineralisation at Echo Bay is from 1500 +- 10 to 1424 +- 29 Ma old, and extends up to 30 km north and 40 km south of Echo Bay. The JD claims contain small quartz vein deposits dated at 535 +- 164 and 1092 +- 115 Ma. At Mountain Lake, pitchblende in Helikian sandstones overlying the batholith is 1076 +- 96 Ma old. Polymetallic veinlets at Mazenod Lake are 457 +- 26 Ma old. Pitchblende in a giant quartz vein at the Rayrock mine is 511 +- 86 Ma old. Small pitchblende veins east of the batholith along the Coppermine River are between 400 and 660 Ma old. All the deposits are either between approximately 395 and 660 Ma old, or indicate remobilization during this interval. These events may be related to a marine transgression and regression approximately 600 and 350 Ma ago, respectively

  3. The Cigar Lake uranium deposit: an analogue for nuclear fuel waste disposal

    International Nuclear Information System (INIS)

    Cramer, J.J.; McConnell, D.B.; Goodwin, B.W.

    1989-01-01

    Cigar Lake is the site of an ore deposit containing exceptionally high concentrations of uranium. This deposit has features that are analogous to features of concepts being developed internationally for the disposal of nuclear fuel waste deep in crystalline rock formations. An understanding of the geologic history of the Cigar Lake deposit can therefore provide useful insight into the long-term behaviour of nuclear waste vaults constructed in bedrock. There are at least two major ways in which investigations of the Cigar Lake analogue can contribute to environmental assessment studies: (1) Before an assessment is completed, reference to the observations from Cigar Lake may lead to the development of improved assessment models and data for the disposal system. (2) For assessments that have been completed, studies at Cigar Lake can be used to provide validation support for certain aspects of the models and data. They may also provide support for the overall results of the assessments. The second of these topics is developed

  4. Notes on uranium geochemistry applied to the study of intergranitic deposits and their envelope

    International Nuclear Information System (INIS)

    Carrat, H.G.

    1975-01-01

    Research on the natural state of uranium, either in the form of traces in the crystal structure or in intergranitic pitchblende deposits is presented. In the former case the methods considered are those relative to post-magma development, a phenomenon having well established connections with the crystallization of uranite type ores. This can be interpreted as a preconcentration if certain genetics concepts are adopted. New aspects of these relationships will then be reported. In the latter case two kinds of research will be presented, corresponding to two types of hypotheses. First, the laying down of pitchblendes by supergenesis is based on the easy degradation of uraninite under meteoric conditions, which will be considered in the geochemical and paleogeographical contexts. Second, the hydrothermal nature of pitchblendes will find strong support in experimental studies on the fluid inclusions of the ore, its matrix and its immediate envelope and from considerations on depth tectonics [fr

  5. Distribution of iron-oxidizing bacteria in the nordic uranium tailings deposit, elliot lake, ontario, Canada.

    Science.gov (United States)

    Silver, M

    1987-04-01

    Iron-oxidizing bacteria are present within the top 2 m (but not always at the surface) and near the water table-capillary fringe of the vegetated Nordic uranium deposit, Elliot Lake, Ontario, Canada. They are distributed uniformly in the top 0.5 m of unvegetated tailings. The locations of these bacteria correlate with zones of pyrite oxidation as delineated in previous studies by the formation of soluble iron and sulfate. Heterotrophic bacteria are also present in the tailings, with greatest concentrations at the surface and near the water table-capillary fringe. Sulfate-reducing bacteria were detected in the soil and peat at the base of the tailings. The results of this study suggest that the establishment of vegetation directly upon the tailings surface does not arrest bacterial pyrite oxidation.

  6. Research on metallogenetic system and palaeo-hydrodynamic analysis on exogenic uranium deposits

    International Nuclear Information System (INIS)

    Ma Liang; Wang Ping

    2008-01-01

    The research and current development trends of sandstone-type uranium deposit at home and abroad are analyzed. A new study idea is put forward in the view of evolution of metallogenetic system i.e. taking the dynamics of matter transportation as main clue to restore the regional palaeo- topography at pre-ore stage, ore forming stage and post-ore stage under the principle of system theory in the way of background evolution of regional geology, especially tectonic dynamic evolution and lithofacies and palaeogeography. Palaeo-flowing field at different geological periods in the processing of regional evolution is reestablished by the usage of palaeohydrogeological analysis combined with the theory of groundwater flowing system. Dynamical process of source-transportation-accumulation- reservation of metallogenetic matter is focused on region scale. (authors)

  7. A Uranium-Lead Chronology of Speleothem Deposition in the Canadian Arctic

    Science.gov (United States)

    Gambino, C.; Shakun, J. D.; McGee, D.; Ramezani, J.; Khadivi, S.; Wong, C. I.

    2017-12-01

    The Artic is one of the fastest warming regions on the planet. Currently much of the Arctic is covered by permafrost, which contains approximately 1,700 gigatons of organic carbon. Permafrost thaw could release a substantial amount of this carbon as greenhouse gases into the atmosphere through microbial decomposition, potentially dramatically amplifying anthropogenic warming. However, the risk of permafrost thaw is uncertain, with models exhibiting a wide range of possibilities. Assessing the stability of permafrost during past interglacial periods enables evaluation of the sensitivity of permafrost to warming. Cave mineral deposits (speleothems) in areas currently covered with permafrost can act as a proxy for past permafrost thaw, as liquid water is one criteria of speleothem growth and thus implies thawed ground conditions. Previous uranium-thorium (U-Th) dating of speleothems (n=67) from a wide range of latitudes and permafrost zones across the southern Canadian Rockies, Northwest Territories, and the northern Yukon suggest deposition during Marine Isotope Stage (MIS) 11 and 13. The majority of U-Th dates of these speleothems, however, exceed the U-Th dating limit of 600 ka. In this study, we apply uranium-lead (U-Pb) geochronology to several of these speleothems to extend the records of speleothem growth further back in time. Initial results include a U-Pb age of 428 ± 14 ka that replicates a previous U-Th age of 416.8 ± 7.9 ka, and U-Pb ages on two other speleothems of 870 ± 100 ka and 1502 ± 30 ka. The results of currently in progress U-Pb analyses and a comparison of results with paleo-temperature and ice volume reconstructions will also be presented.

  8. Uranium geochemistry, mineralogy, geology, exploration and resources

    International Nuclear Information System (INIS)

    De Vivo, B.

    1984-01-01

    This book comprises papers on the following topics: history of radioactivity; uranium in mantle processes; transport and deposition of uranium in hydrothermal systems at temperatures up to 300 0 C: Geological implications; geochemical behaviour of uranium in the supergene environment; uranium exploration techniques; uranium mineralogy; time, crustal evolution and generation of uranium deposits; uranium exploration; geochemistry of uranium in the hydrographic network; uranium deposits of the world, excluding Europe; uranium deposits in Europe; uranium in the economics of energy; role of high heat production granites in uranium province formation; and uranium deposits

  9. Irradiation defects in clayey minerals in association with discordance-type uranium deposit; Les Defauts d'Irradiation dans les Mineraux argileux associes aux gisements d'Uranium de type Discordance

    Energy Technology Data Exchange (ETDEWEB)

    Morichon, E.; Beaufort, D. [Universite de Poitiers, Laboratoire HydrASA, CNRS-FRE 3114, 86 - Poitiers (France); Morichon, E.; Allard, Th. [IMPMC, UMR 7590, 75 - Paris (France)

    2009-07-01

    Radioactivity generates defects in minerals and these defects are the witnesses of the presence of radio-elements, and therefore represent an interesting potential for uranium prospecting. Investigations made in the Athabasca basin in Canada reveal irradiation defects in very old clays (kaolinite, illite and sudoite) in the alteration halo of discordance-type uranium deposits. The authors comment the defect concentration variation among the different drillings. These differences show that hexavalent uranium circulated in the whole geological system

  10. Age and paragenesis of mineralisation at Coronation Hill uranium deposit, Northern Territory, Australia

    Science.gov (United States)

    Orth, Karin; Meffre, Sebastien; Davidson, Garry

    2014-06-01

    Coronation Hill is a U + Au + platinum group elements deposit in the South Alligator Valley (SAV) field in northern Australia, south of the better known unconformity-style U East Alligator Rivers (EAR) field. The SAV field differs from the EAR by having a more complex basin-basement architecture. A volcanically active fault trough (Jawoyn Sub-basin) developed on older basement and then was disrupted by renewed faulting, before being buried beneath regional McArthur Basin sandstones that are also the main hanging wall to the EAR deposits. Primary mineralisation at Coronation Hill formed at 1607 ± 26 Ma (rather than 600-900 Ma as previously thought), and so it is likely that the SAV was part of a single west McArthur Basin dilational event. Most ore is hosted in sub-vertical faults and breccias in the competent volcanic cover sequence. This favoured fluid mixing, acid buffering (forming illite) and oxidation of Fe2+ and reduced C-rich assemblages as important uranium depositional mechanisms. However, reduction of U in fractured older pyrite (Pb model age of 1833 ± 67 Ma) is an important trap in diorite. Some primary ore was remobilised at 675 ± 21 Ma to form coarse uraninite + Ni-Co pyrite networks containing radiogenic Pb. Coronation Hill is polymetallic, and in this respect resembles the `egress'-style U deposits in the Athabascan Basin (Canada). However, these are all cover-hosted. A hypothesis for further testing is that Coronation Hill is also egress-style, with ores formed by fluids rising through basement-hosted fault networks (U reduction by diorite pyrite and carbonaceous shale), and into veins and breccias in the overlying Jawoyn Sub-basin volcano-sedimentary succession.

  11. Uranium exploration target selection for proterozoic iron oxide/breccia complex type deposits in India

    International Nuclear Information System (INIS)

    Dwivedy, K.K.; Sinha, K.K.

    1997-01-01

    Multimetal iron oxide/breccia complex (IOBC) type deposits exemplified by Olympic Dam in Australia, fall under low grade, large tonnage deposits. A multidisciplinary integrated exploration programme consisting of airborne surveys, ground geological surveys, geophysical and geochemical investigations and exploratory drilling, supported adequately by the state of the art analytical facilities, data processing using various software and digital image processing has shown moderate success in the identification of target areas for this type of deposits in the Proterozoic terrains of India. Intracratonic, anorogenic, continental rift to continental margin environment have been identified in a very wide spectrum of rock associations. The genesis and evolution of such associations during the Middle Proterozoic period have been reviewed and applied for target selection in the (i) Son-Narmada rift valley zone; (ii) areas covered by Dongargarh Supergroup of rocks in Madhya Pradesh; (iii) areas exposing ferruginous breccia in the western part of the Singhbhum Shear Zone (SSZ) around Lotapahar; (iv) Siang Group of rocks in Arunachal Pradesh; (v) Crystalline rocks of Garo Hills around Anek; and (vi) Chhotanagpur Gneissic complex in the Bahia-Ulatutoli tract of Ranchi Plateau. Of theses six areas, the Son-Narmada rift area appears to be the most promising area for IOBC type deposits. Considering occurrences of the uranium anomalies near Meraraich, Kundabhati, Naktu and Kudar and positive favourability criteria observed in a wide variety of rocks spatially related to the rifts and shears, certain sectors in Son-Narmada rift zone have been identified as promising for intense subsurface exploration. 20 refs, 4 figs, 1 tab

  12. Liquefaction Probability Curves for Surficial Geologic Units

    Science.gov (United States)

    Holzer, T. L.; Noce, T. E.; Bennett, M. J.

    2009-12-01

    Liquefaction probability curves that predict the probability of surface manifestations of earthquake-induced liquefaction are developed for 14 different surficial geologic deposits. The geologic units include alluvial fan, beach ridge, river delta, eolian dune, point bar, floodbasin, natural river levee, abandoned river channel, deep-water lake, lagoonal, sandy artificial fill, and valley train deposits. Probability is conditioned on earthquake magnitude and peak ground acceleration. Curves are developed for water table depths of 1.5 and 5.0 m. Probabilities were derived from complementary cumulative frequency distributions of the liquefaction potential index (LPI) that were computed from 935 cone penetration tests. Most of the curves can be fit with a 3-parameter logistic function, which facilitates computations of probability. For natural deposits with a water table at 1.5 m depth and subjected to an M7.5 earthquake with a PGA = 0.25 g, probabilities range from 0.5 for fluvial point bar, barrier island beach ridge, and deltaic deposits. Retrospective predictions of liquefaction during historical earthquakes based on the curves compare favorably to post-earthquake observations. We also have used the curves to assign ranges of liquefaction probabilities to the susceptibility categories proposed by Youd and Perkins (1978) for different geologic deposits. For the earthquake loading and conditions described above, probabilities range from 0-0.08 for low, 0.09-0.30 for moderate, 0.31-0.62 for high, to 0.63-1.00 for very high susceptibility. Liquefaction probability curves have two primary practical applications. First, the curves can be combined with seismic source characterizations to transform surficial geologic maps into probabilistic liquefaction hazard maps. Geographic specific curves are clearly desirable, but in the absence of such information, generic liquefaction probability curves provide a first approximation of liquefaction hazard. Such maps are useful both

  13. The characteristic of reduced form exciting factors of governing mineralization in hydrothermal uranium deposits and its prospecting significance

    International Nuclear Information System (INIS)

    Liu Guangqing; Lou Xianhong; Li Zhenqiu

    2008-01-01

    Reduced form exciting factors of governing mineralization are discussed. It is indicated that metallogenic conditions of hydrothermal uranium deposits of reduced form exciting factors governing mineralization are ore-forming solution flow into metallogenic space; Eh decreases significantly, and reach reducing condition of mineral deposit. The exciting factors of governing mineralization are divided into internal reduction subclass and environment reduction subclass. Then emphases on the classification, characteristic, formation condition, representative deposits and prospecting significance in this paper. The environment reduction index is put forward to evaluate reducing power of surrounding rock. (authors)

  14. Surficial Geology of Mount Rainier National Park, Washington

    Science.gov (United States)

    Crandell, Dwight Raymond

    1969-01-01

    Much of the ground surface around Mount Rainier volcano is directly underlain by loose geologic deposits that veneer the hard rock formations. Examples of these deposits are sand and gravel bars along the rivers, ridges of loose rock debris beside the glaciers, and sloping aprons of rock fragments beneath almost every cliff. Even though they are generally thin and inconspicuous when compared with the rock formations, these surficial deposits are clues to geologic events that have profoundly influenced the shape of the park's landscape. Thus, from the character and extent of glacial deposits one can judge the age and size of former glaciers that carved the cirques and deep canyons of the park; from the mudflows which streamed down nearly every valley one can infer the age and size of huge landslides of the past that helped determine Mount Rainier's present shape; and from the pumice deposits some of the volcano's recent eruptive activity can be reconstructed. The map (plate 1, in pocket) that accompanies this description of the surficial deposits of Mount Rainier National Park shows the location of the various geologic formations, and the explanation shows the formations arranged in order of their relative age, with the oldest at the bottom. The text describes the surficial deposits in sequence from older to younger. A discussion of the pumice deposits of the park, which were not mapped, is followed by a description of the formations shown on the geologic map. Inspection of the geologic map may lead the viewer to question why the surficial deposits are shown in more detail in a zone several miles wide around the base of the volcano than elsewhere. This is partly because the zone is largely near or above timberline, relatively accessible, and the surficial deposits there can be readily recognized, differentiated, and mapped. In contrast, access is more difficult in the heavily timbered parts of the park, and surficial deposits there are generally blanketed by a dense

  15. Development of the Cerro solo deposit and uranium favorability of the San Jorge Gulf Basin, province of Chubut

    International Nuclear Information System (INIS)

    Navarra, P.R.; Benitez, A.F.

    1997-01-01

    In the future the uranium exploration activities of CNEA would tend to improve the knowledge of geology and uranium favorability; to perform prospection tasks, and research and development in exploration technologies, to contribute to be in a position to meet the requirements of the country in the long term. On the other hand, a strong growth of nuclear capacity is expected in the first two decades of the next century. Based on its promising grade, the Cerro Solo uranium ore deposit was selected in 1990 by the CNEA to carry out an assessment project. The intensive exploration level was accomplished, as follows: definition of general characteristics of the main orebodies; detailed geologic studies; estimation of resources with adequate data; and preliminary selection of mining-milling methods to estimate the potential profitability of the project. The deposit belongs to the sandstone type. The mineralized layers are distributed into the fluvial sandstones and conglomerates of the cretaceous Chubut Group, lying 50 to 130 m deep Resources of the deposit, with an average grade of 0.3% U, in tonnes of recoverable uranium at costs of up to $80/kg U, are: Reasonable Assured Resources (RAR): 800 t U, Estimated Additional Resources, Category I (EAR-I): 2100 t U. Follow-up drilling programmes are being performed at present in some of the target sites defined in the paleochannel that hosts the Cerro Solo deposit, in order to establish the hypothetical resources of the area. The sites were determined as a result of the exploration that CNEA conducted in the Pichinan uranium district. Recently a regional research project was formulated, for the detailed exploration in the San Jorge Gulf Basin, where the Chubut Group is distributed. 17 refs, 4 figs

  16. Analysis on tectonomagmatic evolution and metallogenic geological conditions of rich-large uranium deposits in Nanling uranium-polymetal metallogenic belt, South Jiangxi province

    International Nuclear Information System (INIS)

    Chen Guihua

    2001-01-01

    Nanling is a complicated tectonomagmatic belt. It is also an important uranium-polymetallic metallogenic belt. On the basis of the research achievements of previous researchers, through the detailed stratigraphic, lithologic, litho-paleo-geographic, geochronologic and geochemical studies and the processing of gravimetric and magnetic data, as well as the information extraction of remote sensing data, the authors come to the following conclusions: (1) The Sannan-Xunwu fault is a long-lived (from the Early Sinian to recent time) EW-trending fault; (2) The earth crust in Nanling experienced three time opening-closing with different scales; (3) The Anyuan-Xunwu area is a large thermo-upwelling extensional structure; (4) The above area is considered to be favourable for the formation of rich-large uranium deposit

  17. Developing protocols for geochemical baseline studies: An example from the Coles Hill uranium deposit, Virginia, USA

    International Nuclear Information System (INIS)

    Levitan, Denise M.; Schreiber, Madeline E.; Seal, Robert R.; Bodnar, Robert J.; Aylor, Joseph G.

    2014-01-01

    Highlights: • We outline protocols for baseline geochemical surveys of stream sediments and water. • Regression on order statistics was used to handle non-detect data. • U concentrations in stream water near this unmined ore were below regulatory standards. • Concentrations of major and trace elements were correlated with stream discharge. • Methods can be applied to other extraction activities, including hydraulic fracturing. - Abstract: In this study, we determined baseline geochemical conditions in stream sediments and surface waters surrounding an undeveloped uranium deposit. Emphasis was placed on study design, including site selection to encompass geological variability and temporal sampling to encompass hydrological and climatic variability, in addition to statistical methods for baseline data analysis. The concentrations of most elements in stream sediments were above analytical detection limits, making them amenable to standard statistical analysis. In contrast, some trace elements in surface water had concentrations that were below the respective detection limits, making statistical analysis more challenging. We describe and compare statistical methods appropriate for concentrations that are below detection limits (non-detect data) and conclude that regression on order statistics provided the most rigorous analysis of our results, particularly for trace elements. Elevated concentrations of U and deposit-associated elements (e.g. Ba, Pb, and V) were observed in stream sediments and surface waters downstream of the deposit, but concentrations were below regulatory guidelines for the protection of aquatic ecosystems and for drinking water. Analysis of temporal trends indicated that concentrations of major and trace elements were most strongly related to stream discharge. These findings highlight the need for sampling protocols that will identify and evaluate the temporal and spatial variations in a thorough baseline study

  18. Case history of the discovery of the Jabiluka uranium deposits, East Alligator River region, Northern Territory of Australia

    International Nuclear Information System (INIS)

    Rowntree, J.C.; Mosher, D.V.

    1976-01-01

    Pancontinental Mining Limited acquired exploration rights over an area in the East Alligator River Region, Northern Territory, Australia, in 1970. Subsequently, Getty Oil Development Company Limited acquired a substantial minority interest in the property. The Jabiluka deposits were discovered during the course of exploration and are currently the largest of the four major uranium deposits in the East Alligator River Region. This region at present contains 24% of the western world's reasonably assured resources of uranium. The exploration techniques employed during primary and secondary exploration on the property between 1971 and 1975 and during the delineation of the Jabiluka deposits are discussed in detail. The case history illustrates the exploration philosophy which was successfully employed on the Jabiluka property. The philosophy encompasses the following points: The need for an assessment on the limits of airborne radiometric surveys; the necessity for detection and evaluation of point source anomalies; the necessity for exploration along extensions of favourable lithologies; and the desirability of modification of exploration techniques on different types of anomalies. Some aspects of this philosophy may be useful in exploration for similar stratabound uranium deposits in other areas. (author)

  19. Nuclear criticality safety controls for uranium deposits during D and D at the Oak Ridge Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Haire, M.J.; Jordan, W.C.; Jollay, L.J. III; Dahl, T.L.

    1997-01-01

    The US Department of Energy (DOE) Deputy Assistant Secretary of Energy for Environmental Management has issued a challenge to complete DOE environmental cleanup within a decade. The response for Oak Ridge facilities is in accordance with the DOE ten-year plan which calls for completion of > 95% of environmental management work by the year 2006. This will result in a 99% risk reduction and in a significant savings in base line costs in waste management (legacy waste); remedial action (groundwater, soil, etc.); and decontamination and decommissioning (D and D). It is assumed that there will be long-term institutional control of cascade equipment, i.e., there will be no walk away from sites, and that there will be firm radioactivity release limits by 1999 for recycle metals. An integral part of these plants is the removal of uranium deposits which pose nuclear criticality safety concerns in the shut down of the Oak Ridge Gaseous Diffusion Plant. DOE has initiated the Nuclear Criticality Stabilization Program to improve nuclear criticality safety by removing the larger uranium deposits from unfavorable geometry equipment. Nondestructive assay (NDA) measurements have identified the location of these deposits. The objective of the K-25 Site Nuclear Criticality Stabilization Program is to remove and place uranium deposits into safe geometry storage containers to meet the double contingency principle. Each step of the removal process results in safer conditions where multiple controls are present. Upon completion of the Program, nuclear criticality risks will be greatly reduced

  20. Development of Nitride Coating Using Atomic Layer Deposition for Low-Enriched Uranium Fuel Powder

    Science.gov (United States)

    Bhattacharya, Sumit

    High-performance research reactors require fuel that operates at high specific power and can withstand high fission density, but at relatively low temperatures. The design of the research reactor fuels is done for efficient heat emission, and consists of assemblies of thin-plates cladding made from aluminum alloy. The low-enriched fuels (LEU) were developed for replacing high-enriched fuels (HEU) for these reactors necessitates a significantly increased uranium density in the fuel to counterbalance the decrease in enrichment. One of the most promising new fuel candidate is U-Mo alloy, in a U-Mo/Al dispersion fuel form, due to its high uranium loading as well as excellent irradiation resistance performance, is being developed extensively to convert from HEU fuel to LEU fuel for high-performance research reactors. However, the formation of an interaction layer (IL) between U-Mo particles and the Al matrix, and the associated pore formation, under high heat flux and high burnup conditions, degrade the irradiation performance of the U-Mo/Al dispersion fuel. From the recent tests results accumulated from the surface engineering of low enriched uranium fuel (SELENIUM) and MIR reactor displayed that a surface barrier coating like physical vapor deposited (PVD) zirconium nitride (ZrN) can significantly reduce the interaction layer. The barrier coating performed well at low burn up but above a fluence rate of 5x 1021 ions/cm2 the swelling reappeared due to formation interaction layer. With this result in mind the objective of this research was to develop an ultrathin ZrN coating over particulate uranium-molybdenum nuclear fuel using a modified savannah 200 atomic layer deposition (ALD) system. This is done in support of the US Department of Energy's (DOE) effort to slow down the interaction at fluence rate and reach higher burn up for high power research reactor. The low-pressure Savannah 200 ALD system is modified to be designed as a batch powder coating system using the

  1. Uranium deposition in bones of Wistar rats associated with skeleton development.

    Science.gov (United States)

    Rodrigues, G; Arruda-Neto, J D T; Pereira, R M R; Kleeb, S R; Geraldo, L P; Primi, M C; Takayama, L; Rodrigues, T E; Cavalcante, G T; Genofre, G C; Semmler, R; Nogueira, G P; Fontes, E M

    2013-12-01

    Sixty female Wistar rats were submitted to a daily intake of ration doped with uranium from weaning to adulthood. Uranium in bone was quantified by the SSNTD (solid state nuclear track detection) technique, and bone mineral density (BMD) analysis performed. Uranium concentration as a function of age exhibited a sharp rise during the first week of the experiment and a drastic drop of 70% in the following weeks. Data interpretation indicates that uranium mimics calcium. Results from BMD suggest that radiation emitted by the incorporated Uranium could induce death of bone cells. © 2013 Elsevier Ltd. All rights reserved.

  2. The geochemical characteristics of alkali metasomatic ore and its ore-forming significance at Zoujiashan deposit, Xiangshan uranium field

    International Nuclear Information System (INIS)

    Wang Yun; Hu Baoqun; Sun Zhanxue; Li Xueli; Guo Guolin; Rao Minghui

    2012-01-01

    Alkaline metasomatites are widely distributed in Zoujiashan uranium deposit and have close relation with uranium mineralization. Based on the study of field geological survey, petrographic methods, element chemical analysis and EPMA, etc, the alteration in alkaline metasomatic ore was found in the order of sodium metasomatism, potassium metasomatism and silica metasomatism. The alkaline hydrothermal fluid of mineralization is rich in Na at first and then rich in K, and quite similar in other chemical composition, but the K rich one is more favourite for the metallization. Compared with the normal porphyroclastic lava, the alkaline metasomatic ores in lower in SiO 2 , but higher in K 2 O or Na 2 O, Al 2 O 3 , Fe 2 O 3 , MgO, P 2 O 5 , CaO and U, Th, Zr, Hf, Sm, Ti, REE. Compared with potassium metasomatic ore, the sodium metasomatic ore is with high ΣLREE/ΣHREE ratio and lower Rb and REE. Because alkaline metasomatism is beneficial to release uranium from accessory mineral and bring out uranium from rocks, therefore it is very important to the migration and precipitation of uranium. (authors)

  3. Mineral potential of Malawai. 3. Mineral deposits associated with sedimentary and volcanic cover rocks: Karoo and post-Karoo (coal, uranium, industrial minerals and gemstone)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    This report was produced for the Ministry of Energy and Mines of Malawi. It gives information and maps of uranium deposits, coal deposits, coal-bed methane, natural gas and helium potential, limestone deposits and gemstones (blue agate, chalcedony and kimerlites, the primary source of diamonds). 2 figs., 2 tabs., 4 maps, 5 photos.

  4. To prospect for mesozoic large and superlarge volcanic type uranium deposits by outlining the specific positions of geological structure

    International Nuclear Information System (INIS)

    Yang Zhenqian

    1994-01-01

    The author analyses the specific positions for Mesozoic large and superlarge volcanic type uranium deposits--geological environment of uranium-bearing volcanic collapse (down faulting) basin, which are characterized by being adjacent to the regional tectonic-magmatic belt, accompanied with sedimentary basin, formed in the early stage of volcanic depression, uplifted in the late stage of basin development, cut by crustal faults, under lain by acidic rock basement and accompanied by extensive argillation. On the basis of discussing the formation mechanism of this type of uranium deposit, nine location criteria for the specific positions are proposed, namely: mobile tectonic-magmatic zone at the intersection of the first and second order tectonic elements; large sized volcano-sedimentary basin at the margin of mobile tectonic-magmatic zone; small sized embayed volcanic collapse (down faulting) basin at the margin of volcano-sedimentary basin; well-developed volcanic rocks in volcanic collapse (down faulting) basin; uplifting of volcanic collapse (down faulting) basin in the later stage of basin development; volcanic collapse (down faulting) basin controlled by a crustal fault with long-term activities; multiple phases of granitic massif developed in the basement of volcanic collapse (down faulting) basin; cover of volcanic collapse (down faulting) basin underwent intense moderate-low temperature volume alteration (mainly as argillation); volume alteration is superimposed by silicification, low temperature albitization, ferrichloritization and anomalies of uranium and associated elements are encountered

  5. Uranium occurrences in the Gordonia and Kuruman districts

    International Nuclear Information System (INIS)

    Levin, M.

    1978-11-01

    This report highlights uranium occurrences discovered by the author in the Kuruman and Gordonia Districts. These discoveries are the result of follow-up work of the regional geological, hydrological and hydrochemical studies of the area, undertaken by the Geology Division of the Atomic Energy Board since 1974. A surficial uranium deposit was discovered on the farm Rus en Vrede in the Kuruman District, at the junction of a palaeo-river with the Kuruman River. Uranium occurs in carbonaceous diatomaceous earth, with surface samples assaying up to 308 ppm U 3 O 8 . As uranium is also present in calcrete 18 km south of this deposit, there is a distinct possibility that significant surficial deposits may occur under the Kalahari sand cover in this area. In the Gordonia District an interesting discovery was made on the farm Tsongnapan where four boreholes, drilled for water, intersected radioactive bands in the Dwyka Tillite Formation. These rocks, which outcrop in the northeast corner of the Tsongnapan, also proved to be radioactive. Some 35 km to the east of this occurrence, borehole logging indicated the existence of an anomalous zone near the base of the Dwyka. In some of these boreholes uranium anomalies were also found in the calcrete and gravel of the Kalahari Formation. It is evident, therefore, that the Gordonia District has the potential of becoming an economically important uranium province. A radiometric ground survey of one of the pans indicated that wind and water action is possibly responsible for the local dispersion and segregation of radioactive minerals [af

  6. Epigenetic-hydrothermal origin of the sediment-hosted Muellenbach uranium deposit, Baden-Baden, W-Germany

    International Nuclear Information System (INIS)

    Brockamp, O.; Zuther, M.; Clauer, N.

    1987-01-01

    Upper Carboniferous sediments on the margin of the northern Black Forest granite massif are the host rocks of the Muellenbach uranium deposit. According to K/Ar datings the sericites formed during the Jurassic (150 Ma), an age also interpreted from U/Pb ratios for the crystallization of the pitchblende. Based on vitrinite reflectance the mineralization temperature is estimated to be 240 0 -290 0 C. It is postulated that the hydrothermal solutions were supplied via deep-seated faults bordering and crosscutting the granite massif and the sedimentary trough which is an intramontane basin. In its immediate vicinity the rift valley of the Rhein graben developed. Uranium deposits in comparable settings are supposed to be predominately of epigenetic-hydrothermal origin. (orig./HP)

  7. Tertiary lithofacies and paleo-geographic framework and interlayer oxidation zone sandstone uranium deposits in Longjiang-Zhaozhou area

    International Nuclear Information System (INIS)

    Zhang Zhenqiang

    2003-01-01

    The main points of views for the experiment are: (1) Yi'an formation is mainly composed of limnetic facies of siltstone and fine sandstone, due to weak surface water, limited sedimentation and simple material source; (2) strengthened surface water and enormous material brought from north and west-north and enlarged sedimentation from north to south, the major deposition during Da'an period are channel facies of conglomerate and river bed facies of sandstone; (3) stronger surface water during Taikang period, led alluvial-flood plain facies brown-yellow conglomerate to develop along western margin of the basin, the channel facies of conglomerate and river bed facies of grey-green sandstone, pelitic siltstone were widely formed southward and eastward; (4) according to the lithofacies criterion for in-situ leachable sandstone uranium ore, Taikang formation is an ideal horizon, river bed facies is suitable for interlayer oxidation type uranium deposit. (author)

  8. Determination of gold of No. 501 uranium deposits and soil samples by cold leaching gold in dilute aqua regia and collection on activated charcoal

    International Nuclear Information System (INIS)

    Shen Maogen; Yao Liying.

    1989-01-01

    The gold determination method is described by cold leaching gold in dilute aqua regia and collection on activated charcoal and presents the results obtained in determining gold of uranium deposits and soil samples

  9. Geophysical and geochemical exploration research on basic metallogenic conditions of unconformity-related uranium deposits in the south part of Kangdian earth's axis

    International Nuclear Information System (INIS)

    Zhang Shucheng; Bai Yunsheng; Wu Huishan; Wu Yue; Chang Guilan

    2001-01-01

    In order to find out the unconformity-related large and super large uranium-rich deposits and to explore the prospecting model for the unconformity-related uranium deposits, the geophysical and geochemical exploration on the basic metallogenic conditions of the unconformity-related uranium deposits in the south part of the Kangdian earth's axis has been carried out after the investigation and research into large amounts of information in combination with the analysis and contrasts of the aeromagnetic, aero-radiometric and gravity data. On the basis of synthesizing the airborne survey information, land-based geophysical and geochemical exploration, the physical nature of many types of rocks and the multi-element analytical and determining results of the U, Th, Au, Cu in the soil samples, the geophysical prospecting models on the unconformity-related uranium deposits in this area has been put forward, and two uranium metallogenic prospect areas and one uranium metallogenic prospect belt have been divided. These results have laid a good foundation for finding out the unconformity-related uranium deposits in this area

  10. Metallogenic condition and regularity of inter layered oxidation zone-type sandstone uranium deposit in southwestern part of Turpan-Hami basin, Northwestern China

    International Nuclear Information System (INIS)

    Xiang Weidong; Chen Zhaobo; Chen Zuyi; Yin Jinshuang

    2001-01-01

    Regional geological surveying and drilling evaluation in recent years show that there are very large potential resources of sandstone-type uranium deposits in the southwestern part of Turpan-Hami basin. According to the characteristics of tectonic evolution and sedimentary cover of the basin, the evolution stages and types of the basin are divided, and the favorable development stages for the ore-bearing formation and the formation of uranium deposits in the evolution process are identified. The metallogenic conditions of uranium deposits are deeply discussed from four aspects: basic tectonics, paleoclimate evolution, hydrogeology and uranium source of the region. All these have laid an important foundation for accurate prediction and evaluation of uranium resources in this region. The research indicates that the uranium metallogeny is a process of long-term, multi-stage and pulsation. The authors try to ascertain the role of organic matter in concentrating uranium. The organic matter is of humic type in sandstone host-rock in the studied area, whose original mother material mainly belongs to terrestrial high plant. The maturity of the organic matter is very low, being in low-grade stage of thermal evolution. Correlation analysis and separation experiments show that uranium concentration is closely related with the organic matter, and the organic matter in uranium ore is mainly in the form of humic acid adsorption and humate. For this reason the total organic carbon content is often increased in the geochemical redox zone in epigenetic sandstone-type uranium deposits. It is suggested that the north of China is of great potential for sandstone-type uranium resources

  11. Genetic-Structural relations in some types of spanish uranium deposits; Relaciones genetico-estructurales de algunos tipos de mienralizaciones uraniferas espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Alia Medina, M.

    1962-07-01

    On the spanish hercynian areas there are different types of uraniferous deposits, which may be classified in the following groups: Group I, high temperature magmatic deposits, Group II, low temperature veins and Group III supergenic deposits, generated by weathering of the former ones or by lixiviation of the intra granitic uranium. The deposits belonging to Group I are founding the hercynian ge anticlinal; those of Groups II and III, chiefly in the eugeosyncline. The explanation suggested for these genetic-structural relationships assumes that, in the ge anticlinal, uranium would migrate from the dioritic magmas to form and high temperature deposits. In the eugeosyncline, a large fraction of the uranium would migrate towards more differentiated granites, in which it might partially remain or from which it might have been finally concentrated in the epithermal veins or by later tectonic actions. The Group III deposits ar more frequent in the eugeosyncline, due to the greater abundance of more differentiated intrusive rocks. (Author) 16 refs.

  12. Investigations on the genesis of syngenetic gold-uranium deposits in conglomerates of the Precambrian Pongola Supergroup and Moodies Group including a contribution on the genesis of the epigenetic gold deposits of Klipwal, Kaapvaal Kraton, South Africa

    International Nuclear Information System (INIS)

    Stupp, H.D.

    1984-01-01

    The terrain diagnostics and the results of mineralogical and geochemical investigations are presented and discussed. The gold and uranium deposits in the Pongola rocks are described extensively. The orogeneses are characterized and their enrichment processes interpreted. The obtained results imply application possibilities for the exploration of gold-uranium placers and hydrothermal gold orogenesis. (DG) [de

  13. Hydrogeologic field study of the Koongarra uranium deposit in the Northern Territory of Australia

    International Nuclear Information System (INIS)

    Marley, R.D.

    1990-01-01

    This study is focused on the hydrogeologic characterization of the more southwesterly of the two Koongarra orebodies. The general objective is to augment the current hydrogeologic understanding of groundwater flow so that realistic transport models can be developed. Water level, aquifer tests, and slug-test data indicate that the Koongarra uranium deposit is within a low permeability, semi-confined, fractured-schist aquifer. Water levels demonstrate semi-diurnal and diurnal fluctuations related to earth tides and evapotranspiration stresses. Hydraulic test data were analyzed with homogenous isotropic and homogenous anisotropic models which allowed parameter estimation for sub-regions of the study area. Dominant anisotropy is subparallel to lithologic layering and the reverse fault. Slug tests reveal regions controlled by low storage but highly conductive fractures and isolated regions of low conductivity. Hydraulic connection of the weathered zone with the underlying schist is dependent on clay content and fractures. Environmental isotopes indicate ground water has been isolated from the atmosphere for a least 40 years and possibly several thousand years in some locations. Water budget calculations indicate the majority of recharge must be from direct infiltration through the weathered profile to account for the calculated ground-water fluxes. 36 refs., 12 tabs., 52 figs

  14. Geology of the uranium deposits related to the sub-Athabasca unconformity, Saskatchewan

    International Nuclear Information System (INIS)

    Tremblay, L.P.

    1982-01-01

    The Athabasca Basin is a large, oval, dish-shaped structure, 425 km by 225 km (80 000 km 2 ) containing about 1500 m of mainly flat-lying quartz-rich sandstone of the Athabasca Group. The basin lies with marked angular unconformity across a Hudsonian basement of deformed and metamorphosed Archean and Aphebian sedimentary, volcanic and plutonic rocks trending north to northeast beneath the basin. In the Carswell Circular Structure in the central western half of the basin rocks are brought to surface through 1200 m of sandstone. The rocks of the basin are less than one percent exposed. Overburden locally reaches 90 m thick. Uranium deposits have been found near the southeast edge of the basin, within the Carswell Circular Structure, and along the northern rim of the basin. They are (1) at the unconformity as high-grade masses elongated in and parallel to major faults, hosted mainly in highly-altered white clay feldspar-rich basement rocks and associated with graphitic metasediments and calc-silicate rocks; (2) within the first 40 m above the unconformity in grey to black and multicoloured Athabasca sandstones and shales as a coating on quartz grains, as disseminations in the clay matrix and as veins; and (3) within 100 m below the unconformity as fracture fillings and disseminations in basement rocks

  15. Effect of depositional environment and sources of pollution on uranium concentration in sediment, coral, algae and seagrass species from the Gulf of Aqaba (Red Sea)

    International Nuclear Information System (INIS)

    Abu-Hilal, A.H.

    1994-01-01

    Uranium concentrations were determined in sediment samples, four hard and two soft corals, one seagrass and four species of algae collected from phosphate-polluted sites in the northern reef area of the Gulf of Aqaba. High uranium concentrations were found in all samples examined from a phosphate-polluted site near a phosphate loading berth compared to the unpolluted ones. Uranium levels, U/Ca ratios, concentration and discrimination factors were also high compared to those reported from other regions of the world. The effects of the exported raw phosphate powder as the main source of pollution and depositional environment on the concentration of uranium in the examined species are discussed. (Author)

  16. Typology and Geographic Geotectonic Distribution of Uranium Deposits Typologie et répartition géographique/géotectonique des gisements d'uranium

    Directory of Open Access Journals (Sweden)

    Dahlkamp F. J.

    2006-11-01

    Full Text Available In the last ten years, twenty new uranium deposits have been discovered. They provide nearly 50% of the known and reasonably assured resources. The most important deposits known in the past by size and ore grade were those found in oligomictic quartz pebble conglomerates, sandstones and, to a lesser extent, hydrothermal veins. The types found more recently, which are greater in quantity than the former ones, are of the vein type (Canada, Australia as well as of the intrusive type (Rössing, Namibia and in calcretes (Yeelirrie, Australia and acid volcanic rocks (Mexico. Several classifications have been worked out in the past (E. W. Heinrich, 1958; M. Roubault, 1958; A. Mancher, 1962. More recently new data have enabled these classifications to be extended on a worldwide basis (Ruzicka, 1971; Ziegler, 1974; Dahlkamp, 1974, 1978 or on a regional basis (McMillon for Canada, 1978; Ingram for Australia, 1974. This classification attempt takes all available useful data into consideration to define different types of uranium deposits in as comprehensive and strict a manner as possible. Pendant les dix dernières années 20 nouveaux types de gisements d'uranium ont été découverts. Ils contribuent à assurer près de 50 % des ressources connues raisonnablement assurées. Dans le passé, les gisements les plus importants par la taille et la teneur en minerai étaient ceux des conglomérats à galets de quartz monogéniques, ceux des grès et, dans une plus faible mesure, ceux des filons hydrothermaux. Les nouveaux types connus, qui dépassent les premiers par la quantité, sont classés en gisements filoniens (Canada, Australie aussi bien qu'en intrusifs (Rössing, Namibie, en calcrêtes (Yeelirie, Australie et volcaniques acides (Mexique. Plusieurs classifications furent élaborées dans le passé (E. W. Heinrich, 1958 ; M. Roubault, 1958 ; A. Mancher, 1962. Plus récemment les données recueillies ont permis de les développer sur une base mondiale

  17. Impact of uranium mining activity on cave deposit (stalagmite) and pine trees (S-Hungary)

    Science.gov (United States)

    Siklosy, Z.; Kern, Z.; Demeny, A.; Pilet, S.; Leel-Ossy, Sz.; Lin, K.; Shen, C.-C.; Szeles, E.

    2009-04-01

    Speleothems are well known paleoclimate archives but their potential for monitoring environmental pollution has not been fully explored. This study deals with an actively growing stalagmite whose trace-element concentration suggests anthropogenic contamination, rather then natural forcing. Paralell, as a potential independent chemo-enviromental archive, living pine (Pinus sylvestis) trees were also involved into investigation. U production in S-Hungary started in 1957 and was expanded closer to the cave site in 1965, covering a mining plot area of ca. 65 km2. The deep-level ore production ended in 1997 and remediation of the mine site has since been completed. Our objective was to determine the possible effect of the four-decade-long uranium (U) ore mining activity on the environment, as recorded by a cave deposit and the pine trees. The Trio Cave is located in the Mecsek Mts (S-Hungary), ca. 1.5-3 km east from the nearest air-shaft and entrance of the uranium mine. A stalagmite located about 150 m away from the cave entrance was drilled and the core investigated for stable isotope and trace element compositions. Pine trees were sampled by increment borer. Continuous flow mass spectrometry was applied on carbonate samples and laser ablation ICP-MS was applied for trace element analysis of both stalagmite (Siklosy et al., 2009) and pine samples. The youngest 1 cm of the drill core was selected for this study that may represent the last cca. 100 years (based on MC-ICP-MS age dating of older parts of the core) that covers the uranium mining period. The pre-mining period is characterized by systematic co-variations of trace elements (U, P, Si, Al, Ba, Mg, etc.) that can be related to soil activity and precipitation amount. The youngest 1.3 mm, however, records a sudden change in U content uncorrelated with any other variables. Starting from a background value of 0.2-0.3 ppm, the concentration gradually increases to about 2 ppm (within about 1 mm), remains constant for

  18. Literature review of models for estimating soil erosion and deposition from wind stresses on uranium-mill-tailings covers

    Energy Technology Data Exchange (ETDEWEB)

    Bander, T.J.

    1982-11-01

    Pacific Northwest Laboratory (PNL) is investigating the use of a rock armoring blanket (riprap) to mitigate wind and water erosion of an earthen radon-suppression cover applied to uranium-mill tailings. The mechanics of wind erosion, as well as of soil deposition, are discussed in this report. Several wind erosion models are reviewed to determine if they can be used to estimate the erosion of soil from a mill-tailings cover. One model, developed by W.S. Chepil, contains the most-important factors that describe variables that influence wind erosion. Particular features of other models are also discussed, as well as the application of Chepil's model to a particular tailings pile. For this particular tailings pile, the estimated erosion was almost one inch per year for an unprotected tailings soil surface. Wide variability in the deposition velocity and lack of adequate deposition models preclude reliable estimates of the rate at which airborne particles are deposited.

  19. Literature review of models for estimating soil erosion and deposition from wind stresses on uranium-mill-tailings covers

    International Nuclear Information System (INIS)

    Bander, T.J.

    1982-11-01

    Pacific Northwest Laboratory (PNL) is investigating the use of a rock armoring blanket (riprap) to mitigate wind and water erosion of an earthen radon-suppression cover applied to uranium-mill tailings. The mechanics of wind erosion, as well as of soil deposition, are discussed in this report. Several wind erosion models are reviewed to determine if they can be used to estimate the erosion of soil from a mill-tailings cover. One model, developed by W.S. Chepil, contains the most-important factors that describe variables that influence wind erosion. Particular features of other models are also discussed, as well as the application of Chepil's model to a particular tailings pile. For this particular tailings pile, the estimated erosion was almost one inch per year for an unprotected tailings soil surface. Wide variability in the deposition velocity and lack of adequate deposition models preclude reliable estimates of the rate at which airborne particles are deposited

  20. Radon in streams and ground waters of Pennsylvania as a guide to uranium deposits

    International Nuclear Information System (INIS)

    Korner, L.A.; Rose, A.W.

    1977-06-01

    Radon-222, a daughter in the radioactive decay of uranium, has potential as a geochemical guide to uranium ores because of its chemical inertness and its relatively easy determination. The radon contents of 59 stream and 149 ground waters have been determined with a newly designed portable radon detector in order to test the method in uranium exploration. Radon contents of stream waters do not appear useful for reconnaissance uranium exploration of areas like Pennsylvania because of relatively rapid degassing of radon from turbulent waters, and because most radon is derived from nearby influx of ground waters into the streams. Radon in streams near uranium occurrences in Carbon and Lycoming counties is lower than many background streams. Radon in ground water is recommended as a reconnaissance method of uranium exploration because most samples from near mineralized areas are anomalous in radon. In contrast, uranium in ground waters is not anomalous near mineralized areas in Carbon County. Equations are derived to show the relation of radon in ground waters to uranium contents of enclosing rocks, emanation of radon from the solids to water, and porosity or fracture width. Limonites are found to be highly enriched in radium, the parent of radon. A model for detection of a nearby uranium ore body by radon measurement on a pumping well has been developed

  1. Control of remediation of uranium deposit Straz with use of numerical modelling approach

    International Nuclear Information System (INIS)

    Novak, J.; Muzak, J.; Smetana, R.

    2002-01-01

    The chemical mining of uranium on the deposit Straz has caused large contamination of groundwater of cretaceous collectors in Straz block of Northbohemian cretaceous table. The low cenomanian aquifer where the uranium deposit is placed is mainly afflicted. In the cenomanian collector there is now more than 4.8 mil. t dissolved solids mainly SO 4 2- , Al, Fe, NH 4 + etc. The total salinity reaches up to 80 g/l. The upper laying turonian collector is drinking water reservoir for larger region. Its contamination is weaker than in cenomanian collector. Use of complex 3D Transport - Reaction Model can be divided into two separate parts. First modelling step is a quantification of overflow between individual mesh elements calculated out of calibrated mixed-hybrid flow model. Two different types of mathematical models are used to accomplish the task: Flow model based on a primary formulation of finite element method, which calculates spatial distribution of piezometric head and flow velocity vectors in selected points of area considered (finite element mesh nodes). This model exactly describes hydraulic situation in area studied; Flow model based on mixed-hybrid formulation of finite element method. This model strictly complies with exact water balance at inter-element faces. In the second part transport-reaction model based on finite volume method is used for calculations using pre-calculated advective velocity field in the area considered. The finite-element mesh covering about 40 km 2 consists of about 16,000 spatial elements. In the leaching fields area the length of the triangular edge is 100-150 meters, vertically the horizon is split into 9-13 layers. The geological boundary-lines were constructed from a database containing information about almost 10 thousand wells. Permeability parameters are defined on the bases of hydrogeological model calculations (calibration) and their vertical distribution is defined more precisely using the GTIS (Geotechnological

  2. Favourable environments for the deposition of uranium in the Subandean Belt and the Amazon Plain of Peru

    International Nuclear Information System (INIS)

    Canepa, L.; Rosado, F.

    1981-01-01

    The area described is located between the east flank of the eastern Cordillera on the territorial limits with Ecuador, Colombia, Brazil and Bolivia. It covers the morphological areas called sub-Andean zone and Amazon plain. The physiographic characteristics change from west to east. In the eastern Cordillera the morphology is rough, with altitudes of 5000 m. Descending to sub-Andean, it presents a moderate topography with low hills between 1000 and 2500 m. Further east the Amazon plain forms an extensive peneplain with altitudes of 400 m. The stratigraphy of the area includes rocks with ages from the Precambrian (eastern Cordillera) to recent. Outcrops of the Palaeozoic formations are found to the east of the eastern Cordillera. Rocks that belong to the Mesozoic and Cenozoic are extensively distributed in the area, as deposits of continental or deltaic facies. The geological evolution of the area is favourable for the formation of stratiform deposits of uranium. The intensity of the orogenic deformation decreases progressively from west to east. The tendency to low dips favours the conditions of migration and precipitation of uranium. The majority of the geological formations of continental and deltaic origin, as well as igneous bodies of upper Palaeozoic and Tertiary age, have been selected as rocks of good geological uranium favourability, taking into consideration criteria found in other parts of the world. These have been modified to suit local conditions. This area presents similar geological conditions to the eastern side of the Andean Cordillera in Argentina where a number of uranium deposits have been located. (author)

  3. Aluminium phosphate sulphate minerals (APS) associated with proterozoic unconformity-type uranium deposits: crystal-chemical characterisation and petrogenetic significance

    International Nuclear Information System (INIS)

    Gaboreau, St.

    2005-01-01

    Aluminium phosphate sulfate minerals (APS) are particularly widespread and spatially associated with hydrothermal clay alteration in both the East Alligator River Uranium Field (Northern Territory, Australia) and the Athabasca basin (Saskatchewan, Canada), in the environment of proterozoic unconformity-related uranium deposits (URUD). The purpose of this study is both: 1) to characterize the nature and the origin of the APS minerals on both sides of the middle proterozoic unconformity between the overlying sandstones and the underlying metamorphic basement rocks that host the uranium ore bodies, 2) to improve our knowledge on the suitability of these minerals to indicate the paleo-conditions (redox, pH) at which the alteration processes relative to the uranium deposition operated. The APS minerals result from the interaction of oxidising and relatively acidic fluids with aluminous host rocks enriched in monazite. Several APS-bearing clay assemblages and APS crystal-chemistry have also been distinguished as a function of the distance from the uranium ore bodies or from the structural discontinuities which drained the hydrothermal solutions during the mineralisation event. One of the main results of this study is that the index mineral assemblages, used in the recent literature to describe the alteration zones around the uranium ore bodies, can be theoretically predicted by a set of thermodynamic calculations which simulate different steps of fluid-rock interaction processes related to a downward penetrating of hyper-saline, oxidizing and acidic diagenetic fluids through the lower sandstone units of the basins and then into the metamorphic basement rocks. The above considerations and the fact that APS with different crystal-chemical compositions crystallized in a range of fO 2 and pH at which uranium can either be transported in solution or precipitated as uraninite in the host-rocks make these minerals not only good markers of the degree of alteration of the

  4. Uranium mining in Australia

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Known uranium deposits and the companies involved in uranium mining and exploration in Australia are listed. The status of the development of the deposits is outlined and reasons for delays to mining are given

  5. Ground water conditions and the relation to uranium deposits in the Gas Hills area, Fremont and Natrona Counties, Wyoming

    International Nuclear Information System (INIS)

    Marks, L.Y.

    1978-03-01

    As ground water apparently leaches, transports, and deposits uranium in the Gas Hills area, central Wyoming, it is important to understand its distribution, movement, and relation to geology and ore bodies. Water table maps were prepared of the Wind River Basin; the most detailed work was in the Gas Hills area. The water table in the Gas Hills area slopes downward to the northwest, ranges in depth from near the ground surface to more than 200 feet, and has seasonal fluctuation of about five feet. Perched water tables and artesian conditions occur locally. The oxidized-unoxidized rock contact is probably roughly parallel to the water table, and averages about 25 feet above it; although locally the two surfaces are considerably farther apart and the oxidized-unoxidized contact may be below the water table. In many places the gradient of the water table changes near the contact between rocks of different permeability. It is conformable with the structure at some anticlines and its gradient changes abruptly near some faults. Most above-normal concentrations of uranium occur at local water table depressions or at water table terraces where the gradient of the water table flattens. At these places, the uraniferous ground water is slowed and is in contact with the reducing agents in the rocks for a relatively long time. This may allow reduction of soluble transported uranium (U +6 ) to insoluble U +4 ) so that uranium is precipitated

  6. Development and testing of a model for the supergene distribution of uranium and accompanying elements around a known uranium deposit associated with an alkaline intrusion

    International Nuclear Information System (INIS)

    1983-01-01

    This report deals with secondary geochemical dispersion in a subarct environment (Ilimaussaq Complex, south Greenland) of uranium and accompanying elements around a U deposit in which the refractory mineral steenstrupine is the main U-bearing mineral. Weathering profiles, including soils, and sediments in rivers, lakes and fjords have been sampled and studied. Chemical weathering is not well developed. The coarse-grained agpaitic nepheline syenites of the Ilimaussaq Complex are covered by debris of crumbling material and practically without vegetation, but soil profiles and vegetation are developed on glacial deposits and on weathered basement granite. 480 samples have been analysed for 22 elements and the data treated by multivariable analyses with main emphasis on principal component analysis. It was found that U and the other elements have been dispersed during weathering. The sediments in rivers and fjords show low correlation of U with those elements that are associated with U Ilimaussaq. Principal component analysis of the total sample materia of soils and lake and river sediments based on 17 elements makes the identification of the area containing the U deposit possible in the first three dimensions. The elements used are those which correlate with Th in this type of deposit. The statistical significance is however low when singlesample populations, as for instance the C-horizons of soils, are used. 41 refs. (EG)

  7. Geological and geochemical aspects of uranium deposits. A selected, annotated bibliography. Vol. 1

    Energy Technology Data Exchange (ETDEWEB)

    White, M.B.; Garland, P.A. (comps.)

    1977-10-01

    This bibliography was compiled by selecting 580 references from the Bibliographic Information Data Base of the Department of Energy's (DOE) National Uranium Resource Evaluation (NURE) Program. This data base and five others have been created by the Ecological Sciences Information Center to provide technical computer-retrievable data on various aspects of the nation's uranium resources. All fields of uranium geology are within the defined scope of the project, as are aerial surveying procedures, uranium reserves and resources, and universally applied uranium research. References used by DOE-NURE contractors in completing their aerial reconnaissance survey reports have been included at the request of the Grand Junction Office, DOE. The following indexes are provided to aid the user in locating reference of interest: author, keyword, geographic location, quadrangle name, geoformational index, and taxonomic name.

  8. Geological and geochemical aspects of uranium deposits. A selected, annotated bibliography. Vol. 1

    International Nuclear Information System (INIS)

    White, M.B.; Garland, P.A.

    1977-10-01

    This bibliography was compiled by selecting 580 references from the Bibliographic Information Data Base of the Department of Energy's (DOE) National Uranium Resource Evaluation (NURE) Program. This data base and five others have been created by the Ecological Sciences Information Center to provide technical computer-retrievable data on various aspects of the nation's uranium resources. All fields of uranium geology are within the defined scope of the project, as are aerial surveying procedures, uranium reserves and resources, and universally applied uranium research. References used by DOE-NURE contractors in completing their aerial reconnaissance survey reports have been included at the request of the Grand Junction Office, DOE. The following indexes are provided to aid the user in locating reference of interest: author, keyword, geographic location, quadrangle name, geoformational index, and taxonomic name

  9. Spatial variability and geochemistry of rare earth elements in soils from the largest uranium-phosphate deposit of Brazil.

    Science.gov (United States)

    Cunha, Cleyton Saialy Medeiros; da Silva, Ygor Jacques Agra Bezerra; Escobar, Maria Eugenia Ortiz; do Nascimento, Clístenes Williams Araújo

    2018-02-22

    The Itataia uranium-phosphate deposit is the largest uranium reserve in Brazil. Rare earth elements (REEs) are commonly associated with phosphate deposits; however, there are no studies on the concentrations of REEs in soils of the Itataia deposit region. Thus, the objective of the research was to evaluate the concentration and spatial variability of REEs in topsoils of Itataia phosphate deposit region. In addition, the influence of soil properties on the geochemistry of REEs was investigated. Results showed that relatively high mean concentrations (mg kg -1 ) of heavy REEs (Gd 6.01; Tb 1.25; Ho 1.15; Er 4.05; Tm 0.64; Yb 4.61; Lu 0.65) were found in surface soils samples. Soil properties showed weak influence on the geochemical behavior of REEs in soils, except for the clay content. On the other hand, parent material characteristics, such as P and U, had strong influence on REEs concentrations. Spatial distribution patterns of REEs in soils are clearly associated with P and U contents. Therefore, geochemical surveys aiming at the delineation of ore-bearing zones in the region can benefit from our data. The results of this work reinforce the perspective for co-mining of P, U and REEs in this important P-U reserve.

  10. Stratigraphy of the PB-1 well, Nopal I uranium deposit, Sierra Pena Blanca, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, P.; Fayek, M.; Goodell, P.; Ghezzehei, T.; Melchor, F.; Murrell, M.; Oliver, R.; Reyes-Cortes, I.A.; de la Garza, R.; Simmons, A.

    2008-08-01

    The Nopal I site in the Pena Blanca uranium district has a number of geologic and hydrologic similarities to the proposed high-level radioactive waste repository at Yucca Mountain, making it a useful analogue to evaluate process models for radionuclide transport. The PB-1 well was drilled in 2003 at the Nopal I uranium deposit as part of a DOE-sponsored natural analogue study to constrain processes affecting radionuclide transport. The well penetrates through the Tertiary volcanic section down to Cretaceous limestone and intersects the regional aquifer system. The well, drilled along the margin of the Nopal I ore body, was continuously cored to a depth of 250 m, thus providing an opportunity to document the local stratigraphy. Detailed observations of these units were afforded through petrographic description and rock-property measurements of the core, together with geophysical logs of the well. The uppermost unit encountered in the PB-1 well is the Nopal Formation, a densely welded, crystal-rich, rhyolitic ash-flow tuff. This cored section is highly altered and devitrified, with kaolinite, quartz, chlorite, and montmorillonite replacing feldspars and much of the groundmass. Breccia zones within the tuff contain fracture fillings of hematite, limonite, goethite, jarosite, and opal. A zone of intense clay alteration encountered in the depth interval 17.45-22.30 m was interpreted to represent the basal vitrophyre of this unit. Underlying the Nopal Formation is the Coloradas Formation, which consists of a welded lithic-rich rhyolitic ash-flow tuff. The cored section of this unit has undergone devitrification and oxidation, and has a similar alteration mineralogy to that observed in the Nopal tuff. A sharp contact between the Coloradas tuff and the underlying Pozos Formation was observed at a depth of 136.38 m. The Pozos Formation consists of poorly sorted conglomerate containing clasts of subangular to subrounded fragments of volcanic rocks, limestone, and chert

  11. The mechanism of rare elements concentration in the redox front area of interlayer oxidation type sandstone-hosted uranium deposits

    International Nuclear Information System (INIS)

    Chen Zuyi; Guo Qingyin

    2010-01-01

    During the detailed study on the distribution regularity of uranium element in various geochemical zones at interlayer oxidation type sandstone-hosted uranium deposits, it has been discovered that some univalent elements are often concentrated at redox front of interlayer oxidation zone. Sc, Y and REE are typical representatives of these univalent elements. On the basis of a comprehensive analysis of a great number analytic data of various elements in various geochemical zones at sandstone-hosted uranium deposits in the former Soviet Union, the authors expound the regular variation of Eh and pH values at the redox front area, as well as the regular distribution and concentration of both univalent (Sc, Y and REE) and multivalent (U, Se, Mo and V) elements. In fact, the redox front area is an area of rapid change for both oxidation-reduction potential (Eh value), and acidic-alkalic index of medium (pH value). The approximate synchronous increment and decrement of Eh and pH values represent the fundamental reason for the regular distribution and concentration of the above two-group elements. Actually, two kinds of geochemical barriers exist at redox front area: reducing barriers and comprehensive reducing-alkalic barrier. The development of the two-kind barrier and their intensity basically depends on how much sulphide, organic matter and carbonate material exist in initial unoxdized host rocks. (authors)

  12. Influence of Paraiba uranium deposit in the evaluation of radioecological dosimetry from Sao Mamede- PB

    International Nuclear Information System (INIS)

    Damascena, Kennedy Francys Rodrigues; Santos Junior, Jose Araujo; Charfuelan, Juana Maria Jimenez; Amaral, Romilton dos Santos; Silva, Alberto Antonio da; Santos, Josineide Marques do Nascimento; Fernandez, Zahily Herrero; Maciel Neto, Jose de Almeida

    2015-01-01

    Regions with different levels of natural radionuclides should be investigated from the radioecological viewpoint, to establish protection criteria for environment and the population. The municipality of São Mamede in the state of Paraiba, is one of the closest of the uranium deposit in Espinharas - PB, and can be influenced, given its geological formation, which justifies conducting environmental dosimetric studies. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) established in 2008 a value for the environmental equivalent effective dose rate of 2.44 mSv / y, considering the different forms of exposure and outdoor environments and internal. The calculation for estimating the outdoor dose rate considered a factor of 0.2, which corresponds therefore to a dose rate of 0.46 mSv / y for these environments. The objective of this study was to determine the levels of natural ionizing radiation that municipality using estimated effective dose rate measured in air and 1.0 m from the surface, points to the presence of rocky outcrops using portable detector with discriminator combined probe of NaI (Tl) and BGO. The experimental setup allowed the evaluation of eighty-one points, dose rates ranged from 0.34 to 4.0 mSv / y, with an average of 0.76 mSv / y, exceeding the global average by a factor of 9, which characterizes the need to investigate the dosimetry for internal environments, which can define criteria to check a possible estimate of radioecological risk. (author)

  13. STRATIGRAPHY OF THE PB-1 WELL, NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, CHIHUAHUA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    NA

    2005-06-25

    Three wells, PB-1, PB-2, and PB-3, were drilled in 2003 at the Nopal I uranium deposit as part of a natural analogue study to evaluate radionuclide transport processes. The wells penetrate through the Tertiary volcanic section down to the Cretaceous limestone basement, and intersect the top of the regional aquifer system. The PB-1 well, drilled immediately adjacent to the Nopal I ore body, was cored to a depth of 250 m, thus providing an opportunity to document the local stratigraphy. The uppermost unit encountered in the PB-1 well is the Nopal Formation, a densely welded, crystal-rich rhyolitic ash-flow tuff. The cored section is highly altered and devitrified, with kaolinite, quartz, chlorite, and montmorillonite replacing feldspars and much of the groundmass. Breccia zones within the tuff contain fracture fillings of hematite, limonite, and goethite. A zone of intense clay alteration encountered in the depth interval 17.45-22.30 m was interpreted to represent the basal vitrophyre of this unit. Underlying the basal vitrophyre is the Coloradas Formation, which consists of a welded, lithic-rich rhyolitic ash-flow tuff. The cored section of this unit has undergone devitrification and oxidation, and has a similar alteration mineralogy to that observed in the Nopal tuff. The Nopal I ore body is restricted to a brecciated zone that intersects these two volcanic units. A sharp contact between the Coloradas tuff and the underlying Pozos Formation was observed at a depth of 136.38 m. The Pozos Formation in the PB-1 core consists of interbedded, poorly sorted sandstone and conglomerate layers. The conglomeratic clasts consist of subangular to subrounded fragments of volcanic rocks, limestone, and chert. Thin (2-6 m) intervals of intercalated pumiceous tuffs were observed within this unit. The contact between the Pozos Formation and the underlying Cretaceous limestone basement was observed at a depth of 244.4 m.

  14. Australia's uranium

    International Nuclear Information System (INIS)

    Hampson, D.C.

    1980-01-01

    The subject is discussed as follows: structure of the uranium industry in Australia (export policies; development of mining programme; table of export contracts approved by Australian government, 1972; government policy towards the industry 1972-75 and since 1975); reserves (table of Australia's major uranium deposits; estimated world resources of uranium, excluding USSR, Eastern Europe and China; comparison of exploration expenditures and discovery of uranium in Australia and the USA); enrichment; resource potential; future demand (table of nuclear power reactors above 30 MW in operation or under construction, mid-1979; projection of Australian uranium production to 1990); government and union action. (U.K.)

  15. Statistical analysis of soil geochemical data to identify pathfinders associated with mineral deposits: An example from the Coles Hill uranium deposit, Virginia, USA

    Science.gov (United States)

    Levitan, Denise M.; Zipper, Carl E.; Donovan, Patricia; Schreiber, Madeline E.; Seal, Robert; Engle, Mark A.; Chermak, John A.; Bodnar, Robert J.; Johnson, Daniel K.; Aylor, Joseph G.

    2015-01-01

    Soil geochemical anomalies can be used to identify pathfinders in exploration for ore deposits. In this study, compositional data analysis is used with multivariate statistical methods to analyse soil geochemical data collected from the Coles Hill uranium deposit, Virginia, USA, to identify pathfinders associated with this deposit. Elemental compositions and relationships were compared between the collected Coles Hill soil and reference soil samples extracted from a regional subset of a national-scale geochemical survey. Results show that pathfinders for the Coles Hill deposit include light rare earth elements (La and Ce), which, when normalised by their Al content, are correlated with U/Al, and elevated Th/Al values, which are not correlated with U/Al, supporting decoupling of U from Th during soil generation. These results can be used in genetic and weathering models of the Coles Hill deposit, and can also be applied to future prospecting for similar U deposits in the eastern United States, and in regions with similar geological/climatic conditions.

  16. Enumeration and characterization of microorganisms associated with the uranium ore deposit at Cigar Lake, Canada. Informal report

    International Nuclear Information System (INIS)

    Francis, A.J.; Joshi-Tope, G.; Gillow, J.B.; Dodge, C.J.

    1994-03-01

    The high-grade uranium deposit at Cigar Lake, Canada, is being investigated as a natural analog for the disposal of nuclear fuel waste. Geochemical aspects of the site have been studied in detail, but the microbial ecology has not been fully investigated. Microbial populations in an ore sample and in groundwater samples from the vicinity of the ore zone were examined to determine their effect on uranium mobility. Counts of the total number of bacteria and of respiring bacteria were obtained by direct microscopy, and the viable aerobic and anaerobic bacteria were assessed as colony forming units (CFUs) by the dilution plating technique. In addition, the population distribution of denitrifiers, fermenters, iron- and sulfur-oxidizers, iron- and sulfate-reducers, and methanogens was determined by the most probable number (MPN) technique

  17. Geochemical barriers formed during in-situ leaching in ore-bearing horizons of hydrogenic uranium deposit

    International Nuclear Information System (INIS)

    Solodov, E.N.

    1994-01-01

    The behaviour of major metallogenetic element and associated elements on the boundary of the leaching solution transiting to the unchanged natural water in a layered uranium deposit of infiltration origin is studied. Neutralization geochemical barrier and their relevant secondary barriers-degassing barrier and neutralization barrier are defined, and recent accumulation of uranium, rare earth elements and a series of other elements at these barriers are in progress. The action of underground microorganism during this process is pointed out; the neutralization capacity of the ore-hosting terrigenous rocks is determined and the dimension of the matter removal, migration and reprecipitation in the studied system is evaluated. The principal conclusion is that the studied geological media have sufficient protective nature to resist direct and strong leaching action of the solution

  18. Uranium resources, 1983

    International Nuclear Information System (INIS)

    1983-01-01

    The specific character of uranium as energy resources, the history of development of uranium resources, the production and reserve of uranium in the world, the prospect regarding the demand and supply of uranium, Japanese activity of exploring uranium resources in foreign countries and the state of development of uranium resources in various countries are reported. The formation of uranium deposits, the classification of uranium deposits and the reserve quantity of each type are described. As the geological environment of uranium deposits, there are six types, that is, quartz medium gravel conglomerate deposit, the deposit related to the unconformity in Proterozoic era, the dissemination type magma deposit, pegmatite deposit and contact deposit in igneaus rocks and metamorphic rocks, vein deposit, sandstone type deposit and the other types of deposit. The main features of respective types are explained. The most important uranium resources in Japan are those in the Tertiary formations, and most of the found reserve belongs to this type. The geological features, the state of yield and the scale of the deposits in Ningyotoge, Tono and Kanmon Mesozoic formation are reported. Uranium minerals, the promising districts in the world, and the matters related to the exploration and mining of uranium are described. (Kako, I.)

  19. Assessment of uranium deposit types and resources - A worldwide perspective. Proceedings of a technical committee meeting

    International Nuclear Information System (INIS)

    2001-12-01

    The Technical Committee Meeting on Recent Development in Uranium Resources, Production and Demand was held in Vienna from 10 to 13 June 1997. The meeting, held in co-operation with the OECD Nuclear Energy Agency, was successful in bringing together 41 specialists representing 22 Member States and one non-governmental organization (Uranium Institute). A total of 23 papers were presented that report historical reviews and recent developments in the uranium related activities in their respective countries. Each of the papers was indexed separately

  20. Geology and recognition criteria for veinlike uranium deposits of the lower to middle Proterozoic unconformity and strata-related types. Final report

    International Nuclear Information System (INIS)

    Dahlkamp, F.J.; Adams, S.S.

    1981-01-01

    The discovery of the Rabbit Lake deposit, Saskatchewan, in 1968 and the East Alligator Rivers district, Northern Territory, Australia, in 1970 established the Lower-Middle Proterozoic veinlike-type deposits as one of the major types of uranium deposits. The term veinlike is used in order to distinguish it from the classical magmatic-hydrothermal vein or veintype deposits. The veinlike deposits account for between a quarter and a third of the Western World's proven uranium reserves. Lower-Middle Proterozoic veinlike deposits, as discussed in this report include several subtypes of deposits, which have some significantly different geologic characteristics. These various subtypes appear to have formed from various combinations of geologic processes ranging from synsedimentary uranium precipitation through some combination of diagenesis, metamorphism, metasomatism, weathering, and deep burial diagenesis. Some of the deposit subtypes are based on only one or two incompletely described examples; hence, even the classification presented in this report may be expected to change. Geologic characteristics of the deposits differ significantly between most districts and in some cases even between deposits within districts. Emphasis in this report is placed on deposit descriptions and the interpretations of the observers

  1. Geology and recognition criteria for veinlike uranium deposits of the lower to middle Proterozoic unconformity and strata-related types. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Dahlkamp, F.J.; Adams, S.S.

    1981-01-01

    The discovery of the Rabbit Lake deposit, Saskatchewan, in 1968 and the East Alligator Rivers district, Northern Territory, Australia, in 1970 established the Lower-Middle Proterozoic veinlike-type deposits as one of the major types of uranium deposits. The term veinlike is used in order to distinguish it from the classical magmatic-hydrothermal vein or veintype deposits. The veinlike deposits account for between a quarter and a third of the Western World's proven uranium reserves. Lower-Middle Proterozoic veinlike deposits, as discussed in this report include several subtypes of deposits, which have some significantly different geologic characteristics. These various subtypes appear to have formed from various combinations of geologic processes ranging from synsedimentary uranium precipitation through some combination of diagenesis, metamorphism, metasomatism, weathering, and deep burial diagenesis. Some of the deposit subtypes are based on only one or two incompletely described examples; hence, even the classification presented in this report may be expected to change. Geologic characteristics of the deposits differ significantly between most districts and in some cases even between deposits within districts. Emphasis in this report is placed on deposit descriptions and the interpretations of the observers.

  2. Uraninite, Coffinite and Brannerite from Shear-Zone Hosted Uranium Deposits of the Bohemian Massif (Central European Variscan Belt

    Directory of Open Access Journals (Sweden)

    Miloš René

    2017-03-01

    Full Text Available New mineralogical data are presented for shear-zone hosted uranium mineralisation from selected uranium deposits that occur in the Bohemian Massif. The uranium mineralisation is in high-grade metamorphic rocks of the Moldanubian Zone and/or in granitic rocks of the Moldanubian batholith and Bor pluton as complex uraninite–coffinite and uraninite–coffinite–brannerite assemblages. For analysed coffinites and brannerites, anomalous enrichment of Y (up to 3.4 wt % Y2O3 and Zr (up to 13.8 wt % ZrO2 is significant. The microprobe data indicate that coffinites from the Rožná and Okrouhlá Radouň uranium deposits contain variable PbO (0–4.3 wt %, FeO (0–2.5 wt %, Al2O3 (0–3.5 wt %, P2O5 (0–1.8 wt %, and CaO (0.7–3.5 wt %. Brannerite is present in unaltered and altered grains with variable concentrations of U4+ (0–0.5 apfu, U6+ (0.06–0.49 apfu, Ti (0.90–2.63 apfu, Ca (0.09–0.41 apfu, and low concentrations of Al (0–0.19 apfu, Th (0–0.04 apfu, Y (0–0.08 apfu, Zr (0–0.13 apfu and REE (0–0.14 apfu.

  3. Pre-selection tests on geophysical and geochemical exploration methods for in-situ leachable sandstone-type uranium deposit in Erlian Basin

    International Nuclear Information System (INIS)

    Zhang Shouben; Tan Chenglong; Jiang Yongyi; Wu Duanyang

    1997-01-01

    The authors introduce the application tests and their results on the Nuheting deposit using non-conventional geophysical and geochemical methods. Through effective analysis on the screened methods, a method combination for the exploration of the in-situ leachable sandstone-type uranium deposit in Erlian Basin has been presented

  4. Factors controlling localization of uranium deposits in the Dakota Sandstone, Gallup and Ambrosia Lake mining districts, McKinley County, New Mexico

    Science.gov (United States)

    Pierson, Charles Thomas; Green, Morris W.

    1977-01-01

    Geologic studies were made at all of the uranium mines and prospects in the Dakota Sandstone of Early(?) and Late Cretaceous age in the Gallup mining district, McKinley County, New Mexico. Dakota mines in the adjacent Ambrosia Lake mining district were visited briefly for comparative purposes. Mines in the eastern part of the Gallup district, and in the Ambrosia Lake district, are on the Chaco slope of the southern San Juan Basin in strata which dip gently northward toward the central part of the basin. Mines in the western part of the Gallup district are along the Gallup hogback (Nutria monocline) in strata which dip steeply westward into the Gallup sag. Geologic factors which controlled formation of the uranium deposits in the Dakota Sandstone are: (1) a source of uranium, believed to be uranium deposits of the underlying Morrison Formation of Late Jurassic age; (2) the accessibility to the Dakota of uranium-bearing solutions from the Morrison; (3) the presence in the Dakota of permeable sandstone beds overlain by impermeable carbonaceous shale beds; and (4) the occurrence within the permeable Dakota sandstone beds of carbonaceous reducing material as bedding-plane laminae, or as pockets of carbonaceous trash. Most of the Dakota uranium deposits are found in the lower part of the formation in marginal-marine distributary-channel sandstones which were deposited in the backshore environment. However, the Hogback no. 4 (Hyde) Mine (Gallup district) occurs in sandy paludal shale of the backshore environment, and another deposit, the Silver Spur (Ambrosia Lake district), is found in what is interpreted to be a massive beach or barrier-bar sandstone of the foreshore environment in the upper part of the Dakota. The sedimentary depositional environment most favorable for the accumulation of uranium is that of backshore areas lateral to main distributary channels, where levee, splay, and some distributary-channel sandstones intertongue with gray carbonaceous shales and

  5. Sedimentary uranium deposit of the Ipora/Amorinopolis region, state of Goias, Brazil

    International Nuclear Information System (INIS)

    Fernandes, S.M.; Leonardos, O.H.

    1984-01-01

    The uranium mineralization is chiefly found within arkosic sandstones at the base of the Devonian Ponta Grossa Formation. The ore is tabular and concordant with the bedding, the controls being simultaneously litho-stratigraphical and biochemical. Narrow permeable horizons of arkosic sandstone lie between impermeable shale and siltstone layers. Within the permeable horizon, the fossil remains (probably brachiopods) are replaced by uranium minerals. The oxidized iron minerals may have acted as to insulate and preserve the secondary soluble uranium minerals. The mineral paragenesis is represented by renardite, meta - autunite I, fourmarierite, Koninckite, ranquilite, meta-uranocircite II, barite, apatite, calophane, wavelite, varscite, an unnamed uranium mineral, quartz, calcedony, goethite, lepidocrocite and hematite. (Author) [pt

  6. Remote sensing application research of mineralization prospect of uranium-polymetal deposits in west side of Daxinganling

    International Nuclear Information System (INIS)

    Luo Fusheng; Cui Zhenkui; Fang Maolong; Wang Guojuan; Yao Hua

    1998-12-01

    The key of mineral exploration by remote sensing method is the extraction and identification of mineralization-related geologic information from remote sensing data under the guidance of mineralization theory. Remote sensing research of deposits is combined with the analysis of regional geology setting, so as to give full play to the advantage of remote sensing technology. According to the geologic features of the covered area, different kinds of satellite data are, at first, selected and processed with different methods and therefore mineralization-related geologic information is effectively extracted. Then regional geologic setting is discussed and main mineralization-controlled factors, such as uranium-occurred volcanic basins, mineralization-controlled faults and granite bodies, Mesozoic volcanic rock series, volcanic framework, are identified. On the basis of the former study, the remote sensing image models of different kinds of deposits have been established. Finally, multi-source information integration technique has been applied to the assessment of favorable mineralization areas. This research shows that it is feasible to extract and identify mineralization-related information from remote sensing images in complicated and covered areas, and that the study area is favorable for uranium and polymetal deposit explorations because of its favorable geologic setting and mineralization conditions

  7. Radioecological study of the open reservoirs of the North Kazakhstan area uranium-mining deposits

    International Nuclear Information System (INIS)

    Kazymbet, P.K.; Bakhtin, M.M.; Imasheva, B.S.; Bud'ko, O.G.

    2003-01-01

    In the paper the radiological data of open reservoirs in the former uranium-mining enterprise territory and settlements are given. The received data show, that both the Kutunguz river and reservoirs close to uranium-mining enterprise are polluted by radionuclides. On the received data it is possible to assume, that the essential contribution to the Kutunguz river contamination by radioactive substances the acting mine 11 water is giving. (author)

  8. Contribution to the geochemical knowledge of the uranium-radium and thorium families in the southern Vosges. Applications of some results in the prospecting of uranium deposits; Contribution a la connaissance geochimique des familles uranium-radium et du thorium dans les Vosges meridionales. Application de certains resultats en prospection des gisements d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Jurain, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-07-01

    This work's aim is to lead to a more accurate knowledge of the geochemistry of the Uranium-Radium and Thorium families in the Southern Vosges and to apply some of the results to the prospecting of uraniferous deposits: It has been showed: a bond between Calcium-Magnesium and Uranium-Thorium in the calco-alkaline granites. The host minerals of Uranium and Thorium are hornblende, biotite, titanite and epidote. a concentration of Uranium, at present time with secular disequilibrium in a thermal zone where the satellite mineralizations form an epithermal paragenesis. a disequilibrium of the Uranium-Radium family in the supergene minerals of the lead (phosphate and vanadate) showing the present circulations of Uranium. a bond between the radon grade of the spring waters and Uranium-Radium of the rocks. Such a relation allow to realize a prospecting method based on the determination of radioactive gases from the cold spring-waters of a common country. (author) [French] L'etude presentee ici a pour but de conduire a une connaissance plus precise de la geochimie des familles Uranium-Radium et Thorium dans les Vosges meridionales et d'appliquer certains resultats a la prospection des gites uraniferes. Il a ete mis en evidence: une liaison Calcium-Magnesium et Uranium-Thorium dans des granites calco-alcalins. Les mineraux hotes de l'Uranium et du Thorium sont: la hornblende, la biotite, le sphene, l'epidote. une concentration actuelle de l'Uranium en desequilibre seculaire dans une zone thermale ou les mineralisations satellites constituent une paragenese epithermale. un desequilibre de la famille Uranium-Radium dans des mineraux supergenes du plomb (phosphates et vanadates) prouvant les circulations actuelles de l'Uranium. une liaison entre la teneur en Radon des eaux de sources et celle en Uranium-Radium des roches. Une telle liaison permet de realiser une methode de prospection fondee sur le dosage du gaz radioactif des eaux de sources

  9. INITIAL TEST WELL CONDITIONING AT NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, CHIHUAHUA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    R.D. Oliver; J.C. Dinsmoor; S.J. Goldstein; I. Reyes; R. De La Garza

    2005-07-11

    Three test wells, PB-1, PB-2, and PB-3, were drilled at the Nopal I uranium deposit as part of a natural analogue study to evaluate radionuclide transport processes during March-April 2003. The initial pumping to condition the wells was completed during December 2003. The PB-1 well, drilled immediately adjacent to the Nopal I ore body, was continuously cored to a depth of 250 m, terminating 20 m below the top of the measured water level. The PB-2 and PB-3 wells, which were drilled on opposite sides of PB-1 at a radial distance of approximately 40 to 50 m outside of the remaining projected ore body, were also drilled to about 20 m below the top of the measured water level. Each test well was completed with 4-inch (10.2-cm) diameter PVC casing with a slotted liner below the water table. Initial conditioning of all three wells using a submersible pump at low pump rates [less than 1 gallon (3.8 1) per minute] resulted in measurable draw down and recoveries. The greatest drawdown ({approx}15 m) was observed in PB-2, whereas only minor (<1 m) drawdown occurred in PB-3. For PB-1 and PB-2, the water turbidity decreased as the wells were pumped and the pH values decreased, indicating that the contamination from the drilling fluid was reduced as the wells were conditioned. Test wells PB-1 and PB-2 showed increased inflow after several borehole volumes of fluid were removed, but their inflow rates remained less that the pumping rate. Test well PB-3 showed the smallest drawdown and least change in pH and conductivity during initial pumping and quickest recovery with a rise in measured water level after conditioning. The 195 gallons (750 l) of water pumped from PB-3 during conditioning was discharged through a household sponge. That sponge showed measurable gamma radiation, which decayed to background values in less than 12 hours. Preliminary interpretations include filtration of a radioisotope source with a short half-life or of a radioisotope that volatized as the sponge

  10. Properties of uranium and thorium in host rocks of multi-metal (Ag, Pb, U, Cu, Bi, Z, F) Big Kanimansur deposit (Tajikistan)

    International Nuclear Information System (INIS)

    Fayziev, A.R.

    2007-01-01

    Multi-metal Big Kanimansur Deposit host rocks contain high averages of uranium and thorium which are more than clark averages by 7 and 2.5 times accordingly. The second property of radio-active elements distribution are low ratio of thorium to uranium. That criteria can be used as prospecting sings for flanks and depth of know ore fields as well as for new squares of multi-metal mineralisation

  11. Descriptive models of major uranium deposits in China - Some results of the Workshop on Uranium Resource Assessment sponsored by the International Atomic Energy Agency, Vienna, Austria, in cooperation with China National Nuclear Corporation, Beijing, and the U.S. Geological Survey, Denver, Colorado, and Reston, Virginia

    Science.gov (United States)

    Finch, W.I.; Feng, S.; Zuyi, C.; McCammon, R.B.

    1993-01-01

    Four major types of uranium deposits occur in China: granite, volcanic, sandstone, and carbonaceous-siliceous-pelitic rock. These types are major sources of uranium in many parts of the world and account for about 95 percent of Chinese production. Descriptive models for each of these types record the diagnostic regional and local geologic features of the deposits that are important to genetic studies, exploration, and resource assessment. A fifth type of uranium deposit, metasomatite, is also modeled because of its high potential for production. These five types of uranium deposits occur irregularly in five tectonic provinces distributed from the northwest through central to southern China. ?? 1993 Oxford University Press.

  12. Determination of Quality, Quantity, and Geometry of Uranium Deposit at North Tanah Merah, Kalan, West Kalimantan

    International Nuclear Information System (INIS)

    Lilik-Subiantoro; Widiyanta; Widito, P.

    2004-01-01

    The research based on 1997/1998 the systematic prospect ion result which was discovered a uranium mineralization zones indication with in the area of 11,733 m 2 at Tanah Merah. That mineralization were found with in favourable, rock of quartzite that intruded by granitic rock. Uranium minerals are uraninite and brannerite, fill in spots and incontinously WNW-ESE fractures. The aim of this research was to find information about sub surfaces uranium geology characteristic, geometric, and U resources available at North Tanah Merah using shallow geological exploration drilling. The result of drilling at 3 locations arising 60 m depth each, have found some uranium mineralization indications that was identified as in uranium ore lensis. The geometri of the lensis is 5 cm-3 m lenght, 15 cm maximum wide and 5-150 thick. The result of U reserve estimation around 3 drill holes with in 5.064 m 2 area and at 66 m depth, is contain 31.348 tons U with in inferred category. (author)

  13. The application of integrated geophysical methods composed of AMT and high-precision ground magnetic survey to the exploration of granite uranium deposits

    International Nuclear Information System (INIS)

    Qiao Yong; Shen Jingbang; Wu Yong; Wang Zexia

    2014-01-01

    Introduced two methods composed of AMT and high-precision ground magnetic survey were used to the exploration of granite uranium deposits in the Yin gongshan areas middle part of the Nei Monggol. Through experiment of methods and analysis of applicated results, think that AMT have good vertical resolution and could preferably survey thickness of rockmass, position of fracture and deep conditions, space distribution features of fracture zone ect, but it is not clear for rockmass, xenolith of reflection. And high-precision ground magnetic survey could delineate rockmass, xenolith of distribution range and identify the rock contact zone, fracture ect, but it generally measure position and it is not clear for occurrence, extension. That can resolve some geological structures by using the integrated methods and on the basis of sharing their complementary advantages. Effective technological measures are provided to the exploration of deep buried uranium bodies in the granite uranium deposits and outskirt extension of the deposit. (authors)

  14. Geology of uranium and associated ore deposits, central part of the Front Range mineral belt, Colorado

    Science.gov (United States)

    Sims, Paul Kibler; ,

    1959-01-01

    The Central City district and adjoining mining areas in the central part of the Front Range mineral belt have supplied small quantities of uranium ore intermittently since the discovery of pitchblende at Central City in 1871. During the early years of development the uranium production form the region was of national importance, and until 1951 the region was this country's principal domestic source of pitchblende. In recent years, however, the production has been insignificant although the search for uranium has been greater than at any previous time. The pitchblende occurs as a local minor constituent of gold- and silver-bearing base-metal sulfide veins, chiefly valuable for their gold content, which have yielded ores valued at about $200 million.

  15. Uranium and thorium series disequilibrium in quaternary carbonate deposits from the Serra da Bodoquena and Pantanal do Miranda, Mato Grosso do Sul State, central Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Fernando Brenha E-mail: brenha@iag.usp.br; Roque, Arnaldo; Boggiani, Paulo Cesar; Flexor, J.-M

    2001-01-15

    Activities of gamma-ray emitting members of the uranium ({sup 238}U) and thorium ({sup 232}Th) series were measured in a quaternary limestone deposit that outcrops in the southeastern Pantanal Matogrossense Basin and in quaternary tufas deposited at the drainage of the Serra da Bodoquena. It is a first step in a study of the mobilization of uranium and thorium series and its relation to surface hydrology, in a region where carbonate deposits are being continuously dissolved and reprecipitated. The obtained results show that all these deposits are characterized by very low concentrations of uranium and thorium. The {sup 238}U/{sup 226}Ra and {sup 228}Th/{sup 228}Ra activity ratios are significantly different than 1.0, indicating that both series are in radioactive disequilibrium. Although the Serra da Bodoquena deposits seem to be very recent, their very fine granulation and high porosity suggest that they behave as open systems for geochemical exchanges of uranium and thorium series members. The Pantanal do Miranda limestone has a radiocarbon age of 3900 yr BP. Since the thorium series is in disequilibrium it is also concluded that this deposit behaves as an open system for geochemical exchanges.

  16. Metallogenetic prospecting in 1:2,000,000 scale for in-situ leachable sandstone type uranium deposit

    International Nuclear Information System (INIS)

    Wang Zhengbang; Qin Mingkuan; Zhao Ruiquan; Dong Wenming; Li Tiangang; Zheng Dayu; Li Sen; Lin Shuangxing

    2002-01-01

    By introducing the advanced theory and technology of systematic geo-mapping which is popularized in Central-Asian countries, the project is aimed at metallogenic prospecting in 1:2,000,000 scale for in-situ leachable sandstone type uranium deposits in Xinjiang and its adjacent area. Based on the comprehensive understanding of accumulated data and on the field study in both the work area and the abroad nearby, the authors propose creatively a new concept that the uranium mineralization in the area is controlled by the moderate tectonic movements during the last large-scale orogenic movement, and set up a new epi-genetically metallogenic system of Meso-Cenozoic depositional basins. Furthermore, the temporal-spatial evolution of the ore-controlled Himalaya orogenic movement is brought to light, and a new method to reconstruct the palaeo-tectonic and palaeo-hydrodynamic systems is created. Accordingly, the main differences in metallogenic conditions and prospecting evaluation between the work area and the Central-Asian areas are illustrated, and the favorable and unfavorable influences of the reduction by the exudative oil and gas on the sandstone type uranium mineralization in the work area are explained in detail. Finally, on the basis of compiling the systematic geo-maps and summarizing the assessment criteria, 2 metallogenic provinces and 12 prospecting areas are predicted. This conclusion can provide a scientific foundation for strategic plans to be made by leading groups and other branches. Another achievement of the project is that a guidebook of the systematic geo-mapping theory and technology has been compiled, which is beneficial to the spreading of the method

  17. Uranium-iron-silicate phases from the Balkan Metallogenic Zone and the Lenz im Kaltenegg (Styria, Austria) deposit

    International Nuclear Information System (INIS)

    Simova, F.G.

    1985-01-01

    The newly-found mineral phases of U 4+ of the UO 2 -FeO - SiO 2 homologuos series are reported. They have been established in a deposit of remobilized veinlet-disseminated type, falling within the scope of West-Balkan Metallogenic Zone and of the slightly metamorphized sedimentary type deposit, within the scope of the Semmering - Wechsel Massif, the Eastern Alpes. The presence of pyrite, hematite and peroxides, as well as uranium oxides and U-Fe silicates as small crystals determines the high iron content and radioactivity of the altered rocks. A complex of physical and chemical methods of investigation, radiography, scanning electron microscopy and X-ray microspectral analysis were employed to study the ore mineralization. Rour U-Fe-Si minerals, new to science, have been identified, one coming from Austria and three from the West-Balkan Metallogenic Zone of Bulgaria. The specific composition of the uranium mineralization made it possible to determine the Alpine and recent ages of the hydrothermal mineralization

  18. Uranium deposits in the Nord-Limousin; Les gites d'uranium du Nord-Limousin

    Energy Technology Data Exchange (ETDEWEB)

    Sarcia, J.A.; Sarcia, J.A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The authors briefly consider the region in its geographical and geological setting. They describe the main petrographic, metallogenic and tectonic characteristics of the sector investigated by the Atomic Energy Commission since 1947, stressing the form of uraniferous mineral deposits. This short account is intended as a general presentation of the detailed studies which will follow, of which that dealing with the mine Henriette is the first to be published. (author) [French] Les auteurs replacent rapidement la region dans son cadre geographique et geologique. Ils decrivent les principales caracteristiques petrographiques, metallogeniques et tectoniques du secteur etudie par le Commissariat a I'Energie atomique depuis 1947, en insistant sur le mode de gisement des mineralisations uraniferes. Ces quelques pages sont destinees a la presentation generale des etudes de detail qui suivront, dont celle qui concerne la Mine Henriette est la premiere publiee. (auteur)

  19. Contribution to the methods for estimating uranium deposits (1963); Contribution aux methodes d'estimation des gisements d'uranium (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Carlier, A. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-02-15

    Having defined a deposit of economic value according to the marginal theory, the author discriminates several categories of ore reserves according to the degree of knowledge of the deposit and according to the mining stage where the ore is considered. He dismisses the conventional French classification of 'on sight', 'probable' and 'possible' ore categories and suggests more suitable ones. The 'sensu stricto', ore reserves are those for which the random error can be calculated. The notion of the natural contrast of grades in an ore deposit (absolute dispersion coefficient {alpha}) is introduced in relation to this topic. The author considers three types of mining exploration. The first is the random exploration so often met; the second is the logical exploration based on a systematic location of underground works, bore-holes, etc. The third, and hardest to achieve, is the one which minimizes exploration costs for a given level of accuracy. Part of the publication deals with sampling errors such as those resulting from the quartering of a heap of ore (theory of Pierre GY) or those resulting from the use of radiometric measurement of grade. Another part deals with the extension error (entailed by the assimilation of samples to the deposit they are issued from) and gives the essential formulae in order to appraise the random error (Geo-statistics of Matheron). As to the estimator itself the work shows how the disharmony between the ore sample and the associated influence zone can be solved by the way of 'kriging'. The thesis gives numerous examples of the various numerical parameters, characteristics of an uranium deposit (absolute dispersion coefficient) or of an uranium ore (liberation parameter) as well as a few examples of linear correlations between gamma radioactivity and uranium grade. Three complete examples of reserve evaluation are given. The end of the thesis deals with the notion of ruin risk which has to

  20. Monitoring the mass of UF6 gas and uranium deposits in aluminium pipes using X-ray fluorescence and X-ray transmission gauges

    International Nuclear Information System (INIS)

    Packer, T.W.; Smith, S.M.

    1984-12-01

    In order to determine the enrichment of UF 6 gas in centrifuge plant pipework it is necessary to measure the mass of the gas (pressure) and the mass per unit area of any uranium deposited on the pipe. This paper shows that it is possible to determine the pressure of the UF 6 gas in pipes 120 mm in diameter using an energy-dispersive X-ray fluorescence spectrometer. Results are also given of transmission measurements made using a low power X-ray generator operated at two different applied voltages. A method of using the two measurements to determine the mass per unit area of deposited uranium is described. (author)

  1. A combined chemical, isotopic and microstructural study of pyrite from roll-front uranium deposits, Lake Eyre Basin, South Australia

    Science.gov (United States)

    Ingham, Edwina S.; Cook, Nigel J.; Cliff, John; Ciobanu, Cristiana L.; Huddleston, Adam

    2014-01-01

    The common sulfide mineral pyrite is abundant throughout sedimentary uranium systems at Pepegoona, Pepegoona West and Pannikan, Lake Eyre Basin, South Australia. Combined chemical, isotopic and microstructural analysis of pyrite indicates variation in fluid composition, sulfur source and precipitation conditions during a protracted mineralization event. The results show the significant role played by pyrite as a metal scavenger and monitor of fluid changes in low-temperature hydrothermal systems. In-situ micrometer-scale sulfur isotope analyses of pyrite demonstrated broad-scale isotopic heterogeneity (δ34S = -43.9 to +32.4‰VCDT), indicative of complex, multi-faceted pyrite evolution, and sulfur derived from more than a single source. Preserved textures support this assertion and indicate a genetic model involving more than one phase of pyrite formation. Authigenic pyrite underwent prolonged evolution and recrystallization, evidenced by a genetic relationship between archetypal framboidal aggregates and pyrite euhedra. Secondary hydrothermal pyrite commonly displays hyper-enrichment of several trace elements (Mn, Co, Ni, As, Se, Mo, Sb, W and Tl) in ore-bearing horizons. Hydrothermal fluids of magmatic and meteoric origins supplied metals to the system but the geochemical signature of pyrite suggests a dominantly granitic source and also the influence of mafic rock types. Irregular variation in δ34S, coupled with oscillatory trace element zonation in secondary pyrite, is interpreted in terms of continuous variations in fluid composition and cycles of diagenetic recrystallization. A late-stage oxidizing fluid may have mobilized selenium from pre-existing pyrite. Subsequent restoration of reduced conditions within the aquifer caused ongoing pyrite re-crystallization and precipitation of selenium as native selenium. These results provide the first qualitative constraints on the formation mechanisms of the uranium deposits at Beverley North. Insights into

  2. Biological pathways of exposure and ecotoxicity values for uranium and associated radionuclides: Chapter D in Hydrological, geological, and biological site characterization of breccia pipe uranium deposits in Northern Arizona

    Science.gov (United States)

    Hinck, Jo E.; Linder, Greg L.; Finger, Susan E.; Little, Edward E.; Tillitt, Donald E.; Kuhne, Wendy

    2010-01-01

    plant’s or an animal’s life history and surrounding environment. Various species of plants, invertebrates, fishes, amphibians, reptiles, birds, and mammals found in the segregation areas that are considered species of concern by State and Federal agencies were included in the development of the site-specific food web. The utilization of subterranean habitats (burrows in uranium-rich areas, burrows in waste rock piles or reclaimed mining areas, mine tunnels) in the seasonally variable but consistently hot, arid environment is of particular concern in the segregation areas. Certain species of reptiles, amphibians, birds, and mammals in the segregation areas spend significant amounts of time in burrows where they can inhale or ingest uranium and other radionuclides through digging, eating, preening, and hibernating. Herbivores may also be exposed though the ingestion of radionuclides that have been aerially deposited on vegetation. Measured tissues concentrations of uranium and other radionuclides are not available for any species of concern in the segregation areas. The sensitivity of these animals to uranium exposure is unknown based on the existing scientific literature, and species-specific uranium presumptive effects levels were only available for two endangered fish species known to inhabit the segregation areas. Overall, the chemical toxicity data available for biological receptors of concern were limited, although chemical and radiation toxicity guidance values are available from several sources. However, caution should be used when directly applying these values to northern Arizona given the unique habitat and life history strategies of biological receptors in the segregation areas and the fact that some guidance values are based on models rather than empirical (laboratory or field) data. No chemical toxicity information based on empirical data is available for reptiles, birds, or wild mammals; therefore, the risks associated with uranium and other

  3. Multielement statistical evidence for uraniferous hydrothermal activity in sandstones overlying the Phoenix uranium deposit, Athabasca Basin, Canada

    Science.gov (United States)

    Chen, Shishi; Hattori, Keiko; Grunsky, Eric C.

    2018-04-01

    The Phoenix U deposit, with indicated resources of 70.2 M lb U3O8, occurs along the unconformity between the Proterozoic Athabasca Group sandstones and the crystalline basement rocks. Principal component analysis (PCA) is applied to the compositions of sandstones overlying the deposit. Among PCs, PC1 accounts for the largest variability of U and shows a positive association of U with rare earth elements (REEs) + Y + Cu + B + Na + Mg + Ni + Be. The evidence suggests that U was dispersed into sandstones together with these elements during the uraniferous hydrothermal activity. Uranium shows an inverse association with Zr, Hf, Th, Fe, and Ti. Since they are common in detrital heavy minerals, such heavy minerals are not the major host of U. The elements positively associated with U are high in concentrations above the deposit, forming a "chimney-like" or "hump-like" distribution in a vertical section. Their enrichment patterns are explained by the ascent of basement fluids through faults to sandstones and the circulation of basinal fluids around the deposit. The Pb isotope compositions of whole rocks are similar to expected values calculated from the concentrations of U, Th, and Pb except for sandstones close to the deposit. The data suggest that in situ decay of U and Th is responsible for the Pb isotope compositions of most sandstones and that highly radiogenic Pb dispersed from the deposit to the proximal sandstones long after the mineralization. This secondary dispersion is captured in PC8, which has low eigenvalue. The data suggests that the secondary dispersion has minor effect on the overall lithogeochemistry of sandstones.

  4. Preliminary photointerpretation map of landslide and other surficial deposits of the Mount Hamilton quadrangle and parts of the Mount Boardman and San Jose quadrangles, Alameda and Santa Clara Counties, California

    Science.gov (United States)

    Nilsen, Tor H.

    1972-01-01

    The nine San Francisco Bay region counties lie within a geologically active, young, and dynamic part of the central and northern Coast Ranges of California. Significant movements of the earth's crust are occurring here at the present time, posing numerous problems to urbanization, including some of special concern. Geological processes such as fault movements, earthquakes, land subsidence, landsliding, slow downslope movement of bedrock and surficial materials, coastal and stream erosion, flooding, and sedimentation are all potentially hazardous. Because of these factors, an understanding of the operation of physical processes in the bay region is desirable for harmonious, efficient, and safe land-use planning, particularly now, with greatly expanded pressures for urban growth. 

  5. Synchronous egress and ingress fluid flow related to compressional reactivation of basement faults: the Phoenix and Gryphon uranium deposits, southeastern Athabasca Basin, Saskatchewan, Canada

    Science.gov (United States)

    Li, Zenghua; Chi, Guoxiang; Bethune, Kathryn M.; Eldursi, Khalifa; Thomas, David; Quirt, David; Ledru, Patrick

    2018-02-01

    Previous studies on unconformity-related uranium deposits in the Athabasca Basin (Canada) suggest that egress flow and ingress flow can develop along single fault systems at different stages of compressional deformation. This research aims to examine whether or not both ingress and egress flow can develop at the same time within an area under a common compressional stress field, as suggested by the reverse displacement of the unconformity surface by the basement faults. The study considers the Phoenix and Gryphon uranium deposits in the Wheeler River area in the southeastern part of the Athabasca Basin. Two-dimensional numerical modeling of fluid flow, coupled with compressional deformation and thermal effects, was carried out to examine the fluid flow pattern. The results show that local variations in the basement geology under a common compressional stress field can result in both egress and ingress flow at the same time. The fault zone at Phoenix underwent a relatively low degree of deformation, as reflected by minor reverse displacement of the unconformity, and egress flow developed, whereas the fault zone at Gryphon experienced a relatively high degree of deformation, as demonstrated by significant reverse displacement of the unconformity, and ingress flow was dominant. The correlation between strain development and location of uranium mineralization, as exemplified by Gryphon and Phoenix uranium deposits, suggests that the localization of dilation predicted by numerical modeling may represent favourable sites for uranium mineralization in the Athabasca Basin.

  6. Persistent U(IV) and U(VI) following in-situ recovery (ISR) mining of a sandstone uranium deposit, Wyoming, USA

    Science.gov (United States)

    Gallegos, Tanya J.; Campbell, Kate M.; Zielinski, Robert A.; Reimus, P.W.; J.T. Clay,; N. Janot,; J. J. Bargar,; Benzel, William M.

    2015-01-01

    Drill-core samples from a sandstone-hosted uranium (U) deposit in Wyoming were characterized to determine the abundance and distribution of uranium following in-situ recovery (ISR) mining with oxygen- and carbon dioxide-enriched water. Concentrations of uranium, collected from ten depth intervals, ranged from 5 to 1920 ppm. A composite sample contained 750 ppm uranium with an average oxidation state of 54% U(VI) and 46% U(IV). Scanning electron microscopy (SEM) indicated rare high uranium (∼1000 ppm U) in spatial association with P/Ca and Si/O attributed to relict uranium minerals, possibly coffinite, uraninite, and autunite, trapped within low permeability layers bypassed during ISR mining. Fission track analysis revealed lower but still elevated concentrations of U in the clay/silica matrix and organic matter (several 10 s ppm) and yet higher concentrations associated with Fe-rich/S-poor sites, likely iron oxides, on altered chlorite or euhedral pyrite surfaces (but not on framboidal pyrite). Organic C (mining, the likely sequestration of uranium within labile iron oxides following mining and sensitivity to changes in redox conditions requires careful attention during groundwater restoration.

  7. Sulfur isotope geochemistry in the surficial environment : application to mineral exploration and mining in Australia

    International Nuclear Information System (INIS)

    Andrew, A.S.

    1997-01-01

    Future discovery and exploitation of Australian mineral deposits requires innovative use of geochemical and geophysical techniques. Isotopic methods are a powerful tool in understanding the interplay of processes active in the surficial environment and allow tracing of target signatures in exploration for non-outcropping mineralization and in monitoring the impact of mining in this ancient, low relief and fragile landscape. Isotope hydrogeochemistry represents an exciting new exploration technology. Despite only limited testing, S isotope methods could be usefully added to conventional hydrogeochemical surveys. The delta 34 S value of sulfate in groundwaters have proved highly effective for detecting sulfide mineralization and enlarging exploration targets with halos of up to several kilometres. In areas of highly saline groundwaters the delta 34 S value reflects mixing of sulfate derived from oxidation of sulfides and background sulfate derived from aerosol fallout. Isotope hydrogeochemistry is best suited to areas of low relief and low rainfall making it particularly relevant to exploration within the Australian continent. Sulfur isotope values of surface and groundwaters and sediments have been used to recognise and quantify the significance of tailings dam seepage within the Ranger Uranium Mine. A sulfur isotope study of potential S sources in surface and subsurface waters quantified the extent of tailings-dam seepage and has tracked seepage in ground and surface waters. (author)

  8. Guidebook on the development of regulations for uranium deposit development and production

    International Nuclear Information System (INIS)

    1996-02-01

    The main purpose of this guidebook is to discuss the various factors and questions that need to be considered by Government organizations in formulating and implementing a regulatory regime to control uranium resource projects. It also provides examples of regulatory requirements in countries where such regulations have evolved into more mature stages. It provides useful policy and technical guidance and directs the user to where greater detail can be found in the existing literature

  9. Oxidoreduction processus in a uranium deposit (Aumance - Cerilly Permian basin, Allier (France))

    International Nuclear Information System (INIS)

    Coelho, J.

    1982-04-01

    Stratigraphic and tectonic data are briefly reviewed. Then a method giving the oxidoreducing properties of elements and using the chemical oxygen demand is exposed. The study of secondary textures shows the effects of the oxidoreducing process. Three pyrite textures were identified at Cerilly by petrographic observations. They are always bound to a secondary enrichment in uranium and they can be used as an exploration guide. Application of factor analysis confirms the studied phenomenon [fr

  10. Application of combined shrinkage stoping and pillarless sublevel caving mining method to a uranium deposit

    International Nuclear Information System (INIS)

    Fan Changjun

    2012-01-01

    Pillarless sublevel caving mining method was used to mining ores in a uranium mine. Because ore-rock interface changed greatly, this part of ores can not be recovered effectively in the mining process, resulting in the permanent loss of these ores. Aimed at the problem, a combined shrinkage stoping and pillarless sublevel caving mining method is presented. Practices show that the ore recovery is increased, dilution rate is declined, and mining safety is improved greatly by using the combined method. (authors)

  11. Investigation of the characteristics of sandstone type uranium deposits in the Patagonia Region: Recent advances

    International Nuclear Information System (INIS)

    Navarra, P.R.; Tomellini, G.C.; Marveggio, N.M.

    2001-01-01

    In the years 1995 and 1996, additional 16,300 m of drilling was carried out in the Cerro Solo area, Province of Chubut, Patagonia Region. This led to the improvement of the resource estimate of the main orebodies, in tonnes of recoverable uranium at costs of up to $ 80/kg U to the following: reasonable assured resources: 2,200 t U; estimated additional resources (C.I): 900 t U. Additionally, the gathering of specific information gave consideration to the possibility of recovering molybdenum as a byproduct, as well as allowing laboratory tests that provided better understanding on the uranium leachability. Moreover, the derived the geological model will help and facilitate the exploration of the Eastern Slope of the Sierra de Pichinan District, and the regional research programmes in the San Jorge Gulf Basin as a whole. CNEA current priority in relation to the country's uranium resources, is the adoption of a policy that will permit the offering of the final feasibility study of the known orebodies and its exploitation to the private sectors. (author)

  12. Uranium and organic matters: use of pyrolysis-gas chromatography, carbon, hydrogen, and uranium contents to characterize the organic matter from sandstone-type deposits

    Science.gov (United States)

    Leventhal, Joel S.

    1979-01-01

    Organic matter seems to play an important role in the genesis of uranium deposits in sandstones in the western United States. Organic materials associated with ore from the Texas coastal plain, Tertiary basins of Wyoming, Grants mineral belt of New Mexico, and the Uravan mineral belt of Utah and Colorado vary widely in physical appearance and chemical composition. Partial characterization of organic materials is achieved by chemical analyses to determine atomic hydrogen-to-carbon (H/C) ratios and by gas chromatographic analyses to determine the molecular fragments evolved during stepwise pyrolysis. From the pyrolysis experiments the organic materials can be classified and grouped: (a) lignites from Texas and Wyoming and (b) hydrogen poor materials, from Grants and Uravan mineral belts and Wyoming; (c) naphthalene-containing materials from Grants mineral belt and Wyoming; and (d) complex and aromatic materials from Uravan, Grants and Wyoming. The organic materials analyzed have atomic H/C ratios that range from approximately 0.3 to at least 1.5. The samples with higher H/C ratios yield pyrolysis products that contain as many as 30 carbon atoms per molecule. Samples with low H/C ratios are commonly more uraniferous and yield mostly methane and low-molecular-weight gases during pyrolysis.

  13. Preliminary study on features of mineralogical zoning of epigenetic alteration at sandstone-type uranium deposit, Dongsheng area, Ordos basin

    International Nuclear Information System (INIS)

    Xiao Xinjian; Li Ziying; Chen Anping

    2004-01-01

    Sandstone-type uranium deposits located in Dongsheng area, northern Ordos basin, occur in Zhiluo Formation, Middle Jurassic. The Zhiluo Formation is divided into two members. The lower member is further divided into two submembers. The lower submember is dominantly composed of grey sandstone being the ore-hosting horizon; the upper submember consists of grey-green sandstone and mudstone. The upper member of Zhiluo Formation is made of mottled medium-fine grained sandstone and mudstone. Through the microscopic observation and study on sandstones of Zhiluo Formation, authors have established a vertical zonation of epigenetic alteration (from the top to the bottom): the limonitization + clayization + carbonation in the mottled fine-grained sandstone of the upper member of Zhiluo Formation; the green alteration (II) (mainly the chloritization of biotite, as well as the chloritization and epidotization of feldspar) + clayization + carbonation in the grey-green sandstone of the upper submember of the lower member of Zhiluo Formation; and the green alteration (I) (mainly the epidotization of feldspar) + carbonation in grey, grey-white sandstone of the lower submember. The epigenetic alteration basically occurs in grey-green sandstone. The sandstone shows grey-green color because it contains much green biotite (not chlorite). The epigenetic alteration in sandstone layer is closely associated with the uranium ore-formation

  14. Report on airborne radioactivity surveys and the uranium deposits in the Red River region of Texas and Oklahoma

    International Nuclear Information System (INIS)

    Blair, R.G.; Stehle, F.T.; Levich, R.A.

    1973-11-01

    The U. S. Atomic Energy Commission conducted an airborne radioactivity survey of the Red River region of Texas and Oklahoma beginning in December 1955 and ending in May 1956. All or parts of Archer, Clay, and Montague Counties in northern Texas and Carter, Cotton, Jefferson, and Stephens Counties in southern Oklahoma were surveyed. Particular attention was paid to those areas where exposures are found of red beds of the Permian Wichita Group. Field examinations were conducted of anomalies discovered by airborne reconnaissance as well as those reported by private individuals. Forty localities were examined, the majority in sandstones, siltstones, or conglomerates. Uranium and copper minerals were identified at several localities. Ferruginous staining, bleaching of the sandstone color, calcium carbonate cement, and carbonized plant remains are common to the deposits

  15. Methods of mineral potential assessment of uranium deposits: A mineral systems approach

    International Nuclear Information System (INIS)

    Jaireth, S.

    2014-01-01

    Conclusions: • Choice of methods depends on the objective; • Basics: – Know your mineral system (deposit-type): SCIENCE; – Create useful datasets: A MUST; • Mineral system approach can be rewarding. For successful examples visit GA’s website; • Don’t overdo or oversell it (only detailed exploration such as drilling can find a deposit)

  16. Methods and results of mapping of metasomatites of argillizite formation at fluorite-molybdenum-uranium deposit

    International Nuclear Information System (INIS)

    Korsakov, A.I.

    1983-01-01

    Techniques and results of mapping at uranium ore field of argillizites, characterized by the absence of clear metasomatic zonation are presented. A new technique for mapping by means of horizontal cross sections is suggested. Argillization degree in horizontal rock masses is expressed by the extensity indices (characterizing the volumes of rocks subjected to argillization) and intensity ones (degree of the process intensity in the total volume of argillized ores), which are established macroscopically according to ore tinge and microscopically. Results are put on a plan of borehole location according to each hypsometric level and represented with the aid of isolines

  17. Environment of deposition and stratigraphy of the uranium-bearing strata around Beaufort West, South Africa

    International Nuclear Information System (INIS)

    Horowitz, A.

    1976-04-01

    Palynological analyses of some 50 samples collected from uranium-bearing strata - as well as the layers immediately above and below them - around Beaufort West, South Africa, indicate that these sediments were laid down in a wide, rather shallow delta in Late Permian times. Most of the sediments are fluvio-deltaic, and most of the plant remains were transported from the north, the hinterland in those times. A considerable percentage of the microfossils, e.g. Veryhachium and hystrichospheres, are clearly from a marine environment. The occurrence of marine microfossils in the spectrum, as compared with those of terrestrial provenance, increases considerably southwards [af

  18. Deck41 Surficial Seafloor Sediment Description Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Deck41 is a digital summary of surficial sediment composition for 36,401 seafloor samples worldwide. Data include collecting source, ship, cruise, sample id,...

  19. Surficial Geologic Map of Rutland, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital data from VG09-7 Van Hoesen, J., 2009, Surficial Geologic Map of Rutland, Vermont: Vermont Geological Survey Open-File Report VG09-7, 9 plates, scale...

  20. Surficial Geologic Map of Weathersfield, Vermont

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital data from VG2017-5 Wright, S. F., 2017, Surficial Geology and Hydrogeology of the Town of Weathersfield, Vermont: Vermont Geological Survey Open File Report...

  1. Some genetic aspects of hydrothermal uranium deposits in the Bakulja granitoide (Serbia)

    International Nuclear Information System (INIS)

    Jelenkovic, Rade

    1998-01-01

    This paper discusses the influence of temperature and the way of hydrothermal fluids flow in function of both the degree of tectonized granitoid and the origin of solutions, and partly the processes accompanying mineralization expressed through physico-chemical, mineralogical and mechanical alterations of the mother rock. It has been concluded that heat energy exchange is in function of: 1) petrochemical characteristic of a rock the hydrothermal fluids flow through; 2) degree of tectonization of the surrounding mineralized rocks; 3) volume and morphology of the fissured-porous space; 4) form of uranium bonding in mineral carriers; 5) degree of uranium leaching in hydrothermal solutions; 6) the way of hydrothermal fluids flow, and 7) coefficient of heat exchange expressed by distribution of heat energy within a fluid-rock system. It has also been established that contraction of granite volume results from physico-chemical processes that take place within a granitoid-hydrothermal fluid system and its quantification has been carried out. (Author)

  2. Geophysical techniques for exploration of concealed uranium deposits in the Gwalior basin

    International Nuclear Information System (INIS)

    Choudhary, Kalpan; Singh, R.B.

    2004-01-01

    There is no direct geophysical method for the exploration of concealed uranium ore. Scope of geophysics for this in the Gwalior basin comprises delineating the basement topography, demarcation or zones of intense fracturing intersecting the unconformities and to identify the presence of carbonaceous rocks, specially in the graben-like structures. These geophysical problems have been successfully solved in other places by employing IP, resistivity, SP and gravity techniques for basement mapping, identification of fracture zone/shear zone, delineation of electrical conductors like carbonaceous rocks and sulphides. Three such case histories are presented here that include: a). basement and shear/fracture zone mapping in the Vindhyan basin north of Son-Narmada lineament, b). delineation of conductive zone (proved to be carbon phyllite) in the Mahakoshal Group of Kanhara area of Sonbhadra district, UP and c). Identification of a conductive zone, proved to be sulphide body, within the Mahakoshal group in the Gurharpahar area of Sidhi and Sonbhadra districts of MP and UP respectively. In the context of exploration for concealed uranium in the Gwalior basin, it is suggested to employ IP, resistivity, SP, gravity and magnetic methods for delineation of conductive zones like carbonaceous rocks, basement topography, including the graben like structures, fracture zone, geological boundaries and demarcation of the basin boundary. (author)

  3. Selected bibliography on the geology of Canadian deposits and occurrences of uranium and thorium

    International Nuclear Information System (INIS)

    Garneau, D.M.

    1976-01-01

    This bibliography is an update to one published in 1956. References are principally geological and mineralogical. Geophysical and geochemical literature is included only if it deals with specific deposits or occurrences. (E.C.B.)

  4. Yeguang granite and uranium metallogeny

    International Nuclear Information System (INIS)

    Gong Wenshu

    1988-03-01

    The geological, petrologic and geochemical characteristics of rock body of yeguang granite are discussed with emphasis on clarification of occurrence of uranium in rock body and uranium deposit characteristics related to rock body, based on extensive field observations and laboratory test. View points are presented that granite refers to genetic series of terrestial crust transformation tye and uranium deposit is hot water deposit

  5. Formation mechanism of self-potential at ISL-amenable interlayer oxidation zone sandstone-type uranium deposit and the simulation and application of self-potential anomalies

    International Nuclear Information System (INIS)

    Tang Hongzhi; Liu Qingcheng; Su Zhaofeng; Gong Yuling

    2006-01-01

    Based on the analysis of geochemical characteristics and metallogenic physico-chemical conditions of ISL-amenable sandstone-type uranium deposits, the formation mechanism of self-potential field is discussed, a mathematic calculation model has been set up, and the simulation calculation has been performed for self-potential anomalies above uranium ore bodies of ordinary form, features of survey curve are analysed and methods for correcting topography at self-potential anomalies are discussed, and a simulation curve of self-potential in the area of slope topography has been presented. Finally, the availability of the method is demonstrated by an example. (authors)

  6. GIS prospectivity mapping and 3D modeling validation for potential uranium deposit targets in Shangnan district, China

    Science.gov (United States)

    Xie, Jiayu; Wang, Gongwen; Sha, Yazhou; Liu, Jiajun; Wen, Botao; Nie, Ming; Zhang, Shuai

    2017-04-01

    Integrating multi-source geoscience information (such as geology, geophysics, geochemistry, and remote sensing) using GIS mapping is one of the key topics and frontiers in quantitative geosciences for mineral exploration. GIS prospective mapping and three-dimensional (3D) modeling can be used not only to extract exploration criteria and delineate metallogenetic targets but also to provide important information for the quantitative assessment of mineral resources. This paper uses the Shangnan district of Shaanxi province (China) as a case study area. GIS mapping and potential granite-hydrothermal uranium targeting were conducted in the study area combining weights of evidence (WofE) and concentration-area (C-A) fractal methods with multi-source geoscience information. 3D deposit-scale modeling using GOCAD software was performed to validate the shapes and features of the potential targets at the subsurface. The research results show that: (1) the known deposits have potential zones at depth, and the 3D geological models can delineate surface or subsurface ore-forming features, which can be used to analyze the uncertainty of the shape and feature of prospectivity mapping at the subsurface; (2) single geochemistry anomalies or remote sensing anomalies at the surface require combining the depth exploration criteria of geophysics to identify potential targets; and (3) the single or sparse exploration criteria zone with few mineralization spots at the surface has high uncertainty in terms of the exploration target.

  7. Applications of prospecting geochemical techniques to the search for and to the study of uranium deposits in metropolitan France

    International Nuclear Information System (INIS)

    Grimbert, Arnold

    1957-01-01

    After having recalled facts which leaded the CEA to use new geochemical techniques for the prospecting of uranium deposits through sampling and analysis of soils and waters, the author describes the organisation and methods implemented for this prospecting activity: team composition for sampling and analysis, role of each engineer and technician in the prospecting stages (preliminary study, routine prospecting, result interpretation), sampling and analysis processes. He also reports campaigns of geochemical prospecting: study of the La Chapelle Largeau deposit (objectives, geological context, preliminary study, routine prospecting, study of geochemical anomalies), tactical research on Verneix indices (study of radioactivity anomaly discovered by radio-prospecting), strategical searches in a non prospected area in the South of Avallon. The author discusses the issues of efficiency and cost price of this geochemical prospecting technique in soils and in waters. Appendices present the equipment and operation modality for soil sampling, and for soil sample preparation, and principles, equipment and products for soil analysis and for water analysis [fr

  8. Uranium-rich opal from the Nopal I uranium deposit, Peña Blanca, Mexico: Evidence for the uptake and retardation of radionuclides

    Science.gov (United States)

    Schindler, Michael; Fayek, Mostafa; Hawthorne, Frank C.

    2010-01-01

    The Nopal I uranium deposit of the Sierra Peña Blanca, Mexico, has been the focus of numerous studies because of its economic importance and its use as a natural analog for nuclear-waste disposal in volcanic tuff. Secondary uranyl minerals such as uranophane, Ca[(UO 2)(SiO 3OH)] 2(H 2O) 5, and weeksite, (K,Na) 2[(UO 2) 2(Si 5O 13)](H 2O) 3, occur in the vadose zone of the deposit and are overgrown by silica glaze. These glazes consist mainly of opal A, which contains small particles of uraninite, UO 2, and weeksite. Close to a fault between brecciated volcanic rocks and welded tuff, a greenish silica glaze coats the altered breccia. Yellow silica glazes from the center of the breccia pipe and from the high-grade pile coat uranyl-silicates, predominantly uranophane and weeksite. All silica glazes are strongly zoned with respect to U and Ca, and the distribution of these elements indicates curved features and spherical particles inside the coatings. The concentrations of U and Ca correlate in the different zones and both elements inversely correlate with the concentration of Si. Zones within the silica glazes contain U and Ca in a 1:1 ratio with maximum concentrations of 0.08 and 0.15 at.% for the greenish and yellow glazes, respectively, suggesting trapping of either Ca 1U 1-aqueous species or -particles in the colloidal silica. X-ray photoelectron spectroscopy (XPS), Fourier-transform infra-red spectroscopy (FTIR), and oxygen-isotope ratios measured by secondary-ion mass spectrometry (SIMS) indicate higher U 6+/U 4+ ratios, higher proportions of Si-OH groups and lower δ 18O values for the greenish silica glaze than for the yellow silica glaze. These differences in composition reflect increasing brecciation, porosity, and permeability from the center of the breccia pipe (yellow silica glaze) toward the fault (green silica glaze), where the seepage of meteoric water and Eh are higher.

  9. Some problems on target-area selection for searching interstratified infiltration sandstone-type uranium deposits suitable to in-situ leaching

    International Nuclear Information System (INIS)

    Hu Shaokang

    2005-01-01

    The sandstone-type uranium deposits are widely distributed in the world, but only 3 regions where deposits reach uranium province size and are suitable for in-situ leaching have been found. Deposits are all of the interstratified-oxidation type, and developed at the combination sites of the most recent orogenic belt with young or old platforms in form of 'branching, inclining and disappearing' of the former. Geomorphologically, these regions consist of 3 big 'steps' from high mountain regions through lower mountains or hills to the margins of the basin, which are in form of declining slope and form a good hydrodynamic conditions. Climatically, an arid climate was always required for the period of sandstone-type uranium ore formation, while annual evaporation is higher than the annual precipitation, the high mountain regions with high potential energy of water melted from glacier and snow which is thought to be a long-term and steady underground water supplier for lower mountains or hill regions and the margins of the basin. However, in orogenic belt there is a good number of inter-mountain basins with at least two big 'steps' indicating a good potential to discover interstratified-oxidation sandstone-type uranium deposits in coal-bearing basins. Many Chinese and foreign uranium geologists have noticed that there is an east-west oriented Hercynian uranium mineralization belt lying across the middle of Europe, the eastern section is superimposed on the Ural-Tianshan-Mongolian mobile belt and together with the latter it was infected by the Alpine-Himalayan movement in Meso-Cenozoic. This resulted in a complicated metallogenic scene with different ore-forming times, multiple types of deposits, and spatial concentration. In addition, a sub-meridional-oriented 'Vebris belt' running through the eastern part of Asia is considered as combination part of the Central Asian mobile belt with the Western Pacific mobile belt which reflects inhomogeneity in crustal construction of

  10. Late quaternary history and uranium isotopic compositions of ground water discharge deposits, Crater Flat, Nevada

    International Nuclear Information System (INIS)

    Paces, J.B.; Taylor, E.M.; Bush, C.

    1993-01-01

    Three carbonate-rich spring deposits are present near the southern end of Crater Flat, NV, approximately 18 km southwest of the potential high-level waste repository at Yucca Mountain. We have analyzed five samples of carbonate-rich material from two of the deposits for U and Th isotopic compositions. Resulting U-series disequilibrium ages indicate that springs were active at 18 ± 1, 30 ± 3, 45 ± 4 and >70 ka. These ages are consistent with a crude internal stratigraphy at one site. Identical ages for two samples at two separate sites suggest that springs were contemporaneous, at least in part, and were most likely part of the same hydrodynamic system. In addition, initial U isotopic compositions range from 2.8 to 3.8 and strongly suggest that ground water from the regional Tertiary-volcanic aquifer provided the source for these hydrogenic deposits. This interpretation, along with water level data from near-by wells suggest that the water table rose approximately 80 to 115 m above present levels during the late Quaternary and may have fluctuated repeatedly. Current data are insufficient to allow reconstruction of a detailed depositional history, however geochronological data are in a good agreement with other paleoclimatic proxy records preserved throughout the region. Since these deposits are down gradient from the potential repository site, the possibility of higher ground water levels in the future dramatically shortens both vertical and lateral ground water pathways and reduces travel times of transported radionuclides to potential discharge sites

  11. Variation of properties of clayey minerals and associated phases about uranium deposits related to proterozoic discordances; Variation des proprietes des mineraux argileux et des phases associees autour des gisements d'uranium lies aux discordances Proterozoiques

    Energy Technology Data Exchange (ETDEWEB)

    Beaufort, D.; Patrier, P.; Laverret, E.; Gaboreau, St.; Billault, V. [HYDRASA, Universite de Poitiers-CNRS, 86 - Poitiers (France); Quirt, D. [AREVA Resources Canada AREVA Resources Canada Inc., Saskatoon, SK (Canada)

    2009-07-01

    The authors propose explanations for the clayey alteration which surrounds uranium deposits related to proterozoic discordances as it is noticed in Canada (Athabasca) and Australia (Kombolgie). The observed mineral sequences are interpreted as the product of an increasing interaction between infiltrated diagenetic acid and oxidising solutions on the one hand, and platform rocks on the other hand, at temperatures between 150 and 200 C. These interpretations are based on crystallographic and crystallochemical investigations

  12. Uranium in soils and water; Uran in Boden und Wasser

    Energy Technology Data Exchange (ETDEWEB)

    Dienemann, Claudia; Utermann, Jens

    2012-07-15

    The report of the Umweltbundesamt (Federal Environmental Agency) on uranium in soils and water covers the following chapters: (1) Introduction. (2) Deposits and properties: Use of uranium; toxic effects on human beings, uranium in ground water and drinking water, uranium in surface waters, uranium in soils, uranium in the air. (3) Legal regulations. (4) Uranium deposits, uranium mining, polluted area recultivation. (5) Diffuse uranium entry in soils and water: uranium insertion due to fertilizers, uranium insertion due to atmospheric precipitation, uranium insertion from the air. (6) Diffuse uranium release from soils and transfer in to the food chain. (7) Conclusions and recommendations.

  13. Surficial Geologic Map of the Great Smoky Mountains National Park Region, Tennessee and North Carolina

    Science.gov (United States)

    Southworth, Scott; Schultz, Art; Denenny, Danielle; Triplett, James

    2004-01-01

    The Surficial Geology of the Great Smoky Mountains National Park Region, Tennessee and North Carolina was mapped from 1993 to 2003 under a cooperative agreement between the U.S. Geological Survey (USGS) and the National Park Service (NPS). This 1:100,000-scale digital geologic map was compiled from 2002 to 2003 from unpublished field investigations maps at 1:24,000-scale. The preliminary surficial geologic data and map support cooperative investigations with NPS, the U.S. Natural Resource Conservation Service, and the All Taxa Biodiversity Inventory (http://www.dlia.org/) (Southworth, 2001). Although the focus of our work was within the Park, the geology of the surrounding area is provided for regional context. Surficial deposits document the most recent part of the geologic history of this part of the western Blue Ridge and eastern Tennessee Valley of the Valley and Ridge of the Southern Appalachians. Additionally, there is great variety of surficial materials, which directly affect the different types of soil and associated flora and fauna. The surficial deposits accumulated over tens of millions of years under varied climatic conditions during the Cenozoic era and resulted from a composite of geologic processes.

  14. Sedimentation of the basal Kombolgie Formation (Upper Precambrian-Carpentarian) Northern Territory, Australia: possible significance in the genesis of the underlying Alligator Rivers unconformity-type uranium deposits

    International Nuclear Information System (INIS)

    Ojakangas, R.W.

    1979-10-01

    The 1400 to 1500 My old Kombolgie Formation of the MacArthur Basin of the Northern Territory overlies or has overlain unconformity-type uranium deposits including Jabiluka, Ranger, Koongarra, Nabarlek and the small deposits of the South Alligator River Valley. A brief study of the basal portion of the formation showed it to consist entirely of mature conglomerates and quartzose sandstones. Analysis of the bedding types (planar cross beds, trough cross beds and parallel beds) and other sedimentary structures (mainly ripple marks and parting lineation) fit a braided alluvial plain model. A paleocurrent study utilizing about 400 measurements from nine localities located along the westward-facing 250 kilometer-long erosional escarpment of the Arnhem Land Plateau showed the dominant paleocurrent trend to be from west and northwest towards the east and southeast, with local divergence. The data and interpretation presented are relevant to the supergene model of uranium deposition at the unconformity, for they add to the suggestion that additional uranium deposits similar to Jabiluka Two may underlie the Kombolgie Formation eastward from the present escarpment

  15. Changes and events in uranium deposit development, exploration, resources, production and the world supply-demand relationship. Proceedings of a technical committee meeting

    International Nuclear Information System (INIS)

    1997-09-01

    This report consists of the proceedings of the Technical Committee Meeting on Recent Changes and Events in Uranium Deposit Development, Exploration, Resources, Production and the World Supply/Demand Relationship, held in co-operation with the OECD Nuclear Energy Agency (OECD/NEA) in Kiev, Ukraine, from 22 to 26 May 1995. Some of the information from this meeting was also used in preparation of the 1995 edition of ''Uranium - Resources, Production and Demand'' a joint report by the OECD/NEA and the IAEA. At the Beginning of 1995 there were 432 nuclear power plants in operation with a combined electricity generating capacity of 340 GW(e). This represents nearly a 100% increase over the last decade. In 1995 over 2228 TW·h of electricity were generated, equivalent to about 17% of the world's total electricity. To achieve this, about 61,000 t U were required as nuclear fuel. For about a decade and a half uranium production and related activities have been decreasing because of declining uranium prices. For many participants in the nuclear industry there has been little interest in uranium supply because of the oversupplied market condition. The declining production led to the development of a supply and demand balance were production is currently meeting a little over 50% of reactor requirements and the excess inventory is being rapidly drawn down. This very unstable relationship has resulted in great uncertainty about the future supply or uranium. One of the objectives of this Technical Committee meeting was to bring together specialists in the field of uranium supply and demand to collect information on new developments. This helps provide a better understanding of the current situation, as well as providing information to plan for the future. Refs, figs, tabs

  16. Methodology of simulation of underground working in metal mines. Application to a uranium deposit in Australia

    International Nuclear Information System (INIS)

    Deraisme, J.; de Fouquet, C.; Fraisse, H.

    1983-01-01

    For the Ben Lomond (Northern Queensland Australia) underground uranium mining project, studies were carried out to compare the feasibility of different mining methods according to their cost per ton and selectivity, i.e. cut and fill, sublevel stopping and both mixed. First, a geostatistical orebody model was built. The ore grade variability of this model results from the drillhole structural analysis. Working on two dimensional vertical cross sections, the usual hand drawing stope reserve estimate obtained with computer assisted design for each of the three different mining methods is compared with the results obtained with automatic algorithms allocated to the characteristics of each mining method. These algorithms use mathematical morphology to reproduce the geometrical constraints connected with each mining method and/or dynamic programmation. These techniques lead to fully automatic of optimal economical stope design. Comparison is positive: automatic stopes designs are in agreement with hand made drawings, but they can be defined faster through interactive questionning of the computer, and the total maximum profit obtained is a least as high as the best profit found through hand designed projects [fr

  17. Hydrogeochemical situation in the flooding water of a uranium mine - the Niederschlema/Alberoda deposit

    International Nuclear Information System (INIS)

    Wolkersdorfer, C.

    1996-01-01

    For reasons of economic viability and environmental considerations, the former uranium mine Niederschlema/Alberoda near Aue in the Erzgebirge (Ore Mountains) has been flooded since 1991. In statistical and hydrogeochemical evaluation of analyses, each with up to 60 parameters, it is shown that the water in the mine can be classified into three types: drainage water, intermediary water and mine water. All three types show significant differentiation in their chemical characteristics, whereby drainage water has the least mineral content and mine water the most. During the period of examination from January 1991 to December 1994, drainage and intermediary waters revealed no statistically significant changes in their physiochemical parameters, whereas the value of most of the physicochemical parameters of the mine water have increased more or less constantly up to 1994. At the end of 1994 the rate of increases in many of the parameters had slowed down or come to a halt. This is either a result of saturation of the water or it is a balance reaction of limited duration. To determine the hydrodynamic situation of the mine water a tracer experiment was carried out together with numerous deepness dependent temperature, conductibility, pH and redox measurements. (orig./SR) [de

  18. Mass balances by uranium-series disequilibria in natural phosphate deposits and mine products

    International Nuclear Information System (INIS)

    Osmond, J.K.; Cowart, J.B.

    1985-01-01

    In a closed system U-238 is in radioactive equilibrium with its longer lived daughters, U-234, Th-230, and Ra-226. In a system that is open on a time scale of 10 4 to 10 5 years, as in rock weathering, the various daughters and isotopes become separated. Nevertheless, equilibrium still pertains to the total system, so that material balances between weathering components and residual products can be calculated, based on parent-daughter radioactivity ratios. The authors have applied this balancing concept to the weathering of phosphatic ores in central Florida and to phosphate mining products. In the natural system studied in Florida, the leached zones are ten times more extensive than enriched zones, and have higher concentrations of Th-230 and Ra-226 relative to U-238 and U-234. Although there are significant movements of long-lived radio-elements locally, and occasional notable disequilibria of short-lived daughters, leaching by ground water is not a major factor in the regional budget. In the mining process, uranium follows the enriched phosphate and also the clay residues. Thorium and radium follow the clay residues and the gypsum by-product. Mine effluent waters, although somewhat higher in radioactivity than natural waters, do not remove appreciable amounts of the radio-elements

  19. Gamma dosimetry of the uranium deposit in Sao Jose de Espinharas, Paraiba, Brazil

    International Nuclear Information System (INIS)

    Silva, Alberto Antonio da; Santos Junior, Jose Araujo dos; Cunha, Andre Felippe Vieira da; Amaral, Romilton dos Santos; Oliveira, Iane Andrade de; Bezerra, Jairo Dias; Silva, Flavio Ferreira da

    2013-01-01

    Radioecology studies contribute to the monitoring of both anthropic and natural radionuclides, as well as their correlation with the ecosystem and the population. Terrestrial sources, which mainly include the primary radionuclides of the 238 U, 232 Th, and 40 K series, contribute to a higher effective dose received by humanity, with 84% from terrestrial radionuclides and another 16% derived from cosmogenic nuclides. Areas with high levels of natural radiation, above the acceptable limits, are of great relevance for the development of dosimetry studies, whose core aims include the preservation of the environment and the control of the population's exposure to radiation. The town of Sao Jose de Espinharas, Paraiba, Brazil, has a uranium oxide mine with an average grade of 1,200 mg/kg. In the present study, non-destructive, in situ assays were performed along the entire radiometrically anomalous area. The results obtained in terms of effective doses varied from 3.79 to 93.80 mSv.y -1 , with an average of 19.47 mSv.y -1 thus leading to the conclusion that all of the monitored points presented environmental doses of above the reference value of 2.4 mSv.y -1 , suggesting that both qualitative and quantitative analyses concerning the environmental matrixes in question need to be performed. (author)

  20. Characterization of titanite generations from Gameleira-I deposit (U-anomaly 35) Lagoa Real Uranium Province (LRUP), Bahia state, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Camila M. dos; Rios, Francisco Javier; Amorim, Lucas E.D.; Palmieri, Helena E., E-mail: cms@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-11-01

    The Lagoa Real Uranium Province (LRUP) is located in northwest of Bahia state and is the major uranium deposit of Brazil. Titanite is a common accessory mineral in rocks of LRUP and usually is part of uranium ore assemblage. Thirty three polished thin sections of F10 drill-hole located in Gameleira I deposit (anomaly 35) were petrographically studied and used for mineral chemistry study. Petrographically, titanite can be differentiated according to texture between granular and prismatic. Granular titanite is generally associated with magmatic assemblage (alkali feldspar hypersolvus granite) and it is present in some albitites (barren magnetite albitite). Prismatic titanite is restricted to albitite (garnet and mineralized magnetite albitite) and is associated with metamorphic assemblage. Microprobe analyses shows a trend from granites to mineralized albitites and do not cluster titanite by its texture, but by its host rocks. On the other hand, trace elements can distinguish titanite generation according to texture. Granular titanite is characterized by some highest high field strength elements (HFSE) values, like Hf, Pb, Th, U and HREE+Y, and the lowest V content. Vanadium has positive correlation with Zr/Hf ratio and inverse with U. Vanadium versus U relationship is inverse to the previously found by literature in LRUP what indicates that titanite was submitted to complexes processes of uranium loss after its crystallization. In addition, hafnium loss can be related to precipitation of hydrothermal zircon as it is strongly partitioned to this mineral. (author)

  1. Characterization of titanite generations from Gameleira-I deposit (U-anomaly 35) Lagoa Real Uranium Province (LRUP), Bahia state, Brazil

    International Nuclear Information System (INIS)

    Santos, Camila M. dos; Rios, Francisco Javier; Amorim, Lucas E.D.; Palmieri, Helena E.

    2017-01-01

    The Lagoa Real Uranium Province (LRUP) is located in northwest of Bahia state and is the major uranium deposit of Brazil. Titanite is a common accessory mineral in rocks of LRUP and usually is part of uranium ore assemblage. Thirty three polished thin sections of F10 drill-hole located in Gameleira I deposit (anomaly 35) were petrographically studied and used for mineral chemistry study. Petrographically, titanite can be differentiated according to texture between granular and prismatic. Granular titanite is generally associated with magmatic assemblage (alkali feldspar hypersolvus granite) and it is present in some albitites (barren magnetite albitite). Prismatic titanite is restricted to albitite (garnet and mineralized magnetite albitite) and is associated with metamorphic assemblage. Microprobe analyses shows a trend from granites to mineralized albitites and do not cluster titanite by its texture, but by its host rocks. On the other hand, trace elements can distinguish titanite generation according to texture. Granular titanite is characterized by some highest high field strength elements (HFSE) values, like Hf, Pb, Th, U and HREE+Y, and the lowest V content. Vanadium has positive correlation with Zr/Hf ratio and inverse with U. Vanadium versus U relationship is inverse to the previously found by literature in LRUP what indicates that titanite was submitted to complexes processes of uranium loss after its crystallization. In addition, hafnium loss can be related to precipitation of hydrothermal zircon as it is strongly partitioned to this mineral. (author)

  2. Mapping the Surficial Geology of the Arctic Ocean

    Science.gov (United States)

    Mosher, D. C.; Jakobsson, M.; Gebhardt, C.; Mayer, L. A.

    2014-12-01

    Surficial geologic mapping of the Arctic Ocean was undertaken to provide a basis for understanding different geologic environments in this polar setting. Mapping was based on data acquired from numerous icebreaker and submarine missions to the polar region. The intent was to create a geologic layer overlying the International Bathymetric Chart of the Arctic Ocean. Analysis of subbottom profiler and multibeam bathymetric data in conjunction with sediment cores and the regional morphology rendered from the IBCAO data were used to map different surficial geologic units. For a relatively small ocean basin, the Arctic Ocean reveals a plethora of margin and basin types reflecting both the complex tectonic origins of the basin and its diverse sedimentation history. Broad and narrow shelves were subjected to a complex ice-margin history in the Quaternary, and bear the sediment types and morphological features as a result. Some shelfal areas are heavily influenced by rivers. Extensive deep water ridges and plateaus are isolated from coastal input and have a long history of hemipelagic deposition. An active spreading ridge and regions of recent volcanism have volcani-clastic and heavily altered sediments. Some regions of the Arctic Ocean are proposed to have been influenced by bolide impact. The flanks of the basins demonstrate complex sedimentation patterns resulting from mass failures and ice-margin outflow. The deep basins of the Arctic Ocean are filled with turbidites resulting from these mass-flows and are interbedded with hemiplegic deposits.

  3. Studies on hydrogeological conditions for mineralization of some sandstone type uranium deposit

    International Nuclear Information System (INIS)

    Wang Zhiming; Li Sen; Xiao Feng; Qi Daneng; Yin Jinshuang

    1996-11-01

    Based on the analysis for regional geology, structural and hydrogeological conditions of Erennaoer Depression, Erlian Basin, the hydrogeological hydraulic zoning was carried out for groundwater in the study area, structural-palaeo-hydrogeological stages and the feature of deep-seated groundwater were studied, and, two important U-mineralization periods were determined. The conditions of recharge, runoff and discharge of groundwater in ore bearing aquifers and the hydraulic mechanism were revealed by isotope hydrology and single-well tracing technique. By study of hydrogeochemistry, it is indicated that both Subeng and Nuheting U-deposit are located at the parts where groundwater characteristics intensely variate, and the ore indicators are determined. Oil and gas transportation and the relationships between groundwater and U-metallogenetic process were discussed by using of organic geochemistry method. It shows that the bleeding of oil and gas is very important for the forming of U-deposits. It is suggested that the interlayered oxidation zone type sandstone U-deposit which is suitable for in-situ leaching could be existed in the Tenggeer formation, Bayanhua group of Lower Cretaceous, accordingly, two prospecting areas are delimited. (4 refs., 3 figs., 2 tabs.)

  4. Development of data processing system for regional geophysical and geochemical exploration of sandstone-hosted uranium deposits based on ArcGIS Engine

    International Nuclear Information System (INIS)

    Han Shaoyang; Ke Dan; Hou Huiqun; Hu Shuiqing

    2010-01-01

    According to the data processing need of geophysical and geochemical exploration of sandstone-hosted uranium deposits, the function design of the regional geophysical and geochemical data processing system is completed in the paper. The geophysical and geochemical data processing software with powerful functions is also developed based on ArcGIS Engine which remedies the shortage of GIS software for performing the geophysical and geochemical data processing. The development technique route of system software and key techniques are introduced, and the development processes of system software are showed through some development examples. Application practices indicate that the interface of developed system software with friendly interface and utility functions, may quickly perform the data processing of regional geophysical and geochemical exploration and provide the helpful deep information for predicting metallogenic prospective areas of sandstone-hosted uranium deposits. The system software is of a great application foreground. (authors)

  5. Iron oxi-hydroxides characterization and associated elements (S, Se, As, Mo, V, Zr) in the redox environments favorable for uranium deposits

    International Nuclear Information System (INIS)

    Pons, Tony

    2015-01-01

    This work presents a multi-scale and a multi-technical study for the characterization of iron oxi-hydroxides in three uranium-type deposits and host rock. The choice of sites has focused on a roll front deposit: Zoovch Ovoo in a Cretaceous basin of East Gobi (Mongolia); a tectonic-lithological type: Akola/Ebba in Tim Mersoi basin (Niger) and a Proterozoic unconformity type: Kiggavik in Thelon basin (Canada). A new approach has been implemented to characterize the iron oxi-hydroxides on macroscopic samples: field infrared spectroscopy using the ASD TerraSpec spectrometer. From the original indexes calculated on the spectra, it was possible both to characterize the iron oxi-hydroxides; only hematite and goethite were identified in the different parts of oxidized uranium fronts, and visualize the alteration zonation along the redox front. In addition, the visible part of spectrum was used to quantify the color of samples through the IHS system parameters (Intensity - Hue - Saturation) and the Munsell system. The color setting of the study identified a specific hue for mineralized samples studied: a mixture of yellow and red (2.5 to 10 Yr in Munsell notation). At the crystals scale, the iron-hydroxides were characterized by μ-Raman spectroscopy. The study highlighted a difference in crystallinity of hematite crystals in different fields. From a morphological point of view, the crystals of goethite in the Zoovch Ovoo deposit, is only authigenic iron oxi-hydroxides described in this uranium front, are twinned in the form of six-pointed star, reflecting a low crystallization temperature, compared to Niger and Kiggavik deposits. This crystallization is mainly controlled by the availability of Fe(III) ions in the fluid, released by pyrite dissolution in an oxidizing environment and pH. From a chemical point of view, iron oxi-hydroxides record the fluid passage owing their uranium content. Secondly, the composition in trace elements marks the type of deposit, for example

  6. PROCESS OF RECOVERING URANIUM

    Science.gov (United States)

    Carter, J.M.; Larson, C.E.

    1958-10-01

    A process is presented for recovering uranium values from calutron deposits. The process consists in treating such deposits to produce an oxidlzed acidic solution containing uranium together with the following imparities: Cu, Fe, Cr, Ni, Mn, Zn. The uranium is recovered from such an impurity-bearing solution by adjusting the pH of the solution to the range 1.5 to 3.0 and then treating the solution with hydrogen peroxide. This results in the precipitation of uranium peroxide which is substantially free of the metal impurities in the solution. The peroxide precipitate is then separated from the solution, washed, and calcined to produce uranium trioxide.

  7. Rare earth elements in a uranium deposit in Pedra, Pernambuco, Brazil

    International Nuclear Information System (INIS)

    Damascena, Kennedy Francys Rodrigues; Amaral, Romilton dos Santos; Santos Junior, Jose Araujo dos; Bezerra, Jairo Dias; Oliveira, Iane Andrade de; Silva, Alberto Antonio da

    2013-01-01

    Rare Earth Elements (REEs) are similar in the physical and chemical properties of their compounds and are most commonly found in nature associated with terrestrial radionuclides. The high interest in conducting research on REEs is due to their multiple applications and high economic value. In this light, the present study analyzed samples of soil and rocks from an anomalous area replete with uranium and thorium, in the town of Pedra, Pernambuco, Brazil, in an attempt to identify the occurrence and concentrations of these elements. For these analyses, neutron activation, followed by high-resolution gamma spectrometry, was used to define the REEs. The following REEs were identified in the study area: La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, and Sc. The most abundant elements in the region, within samples of soil and rock, respectively, were: Ce (63-503 mg.kg -1 / 19.6 to 2243.5 mg.kg -1 ), Nd (25.0 to 249.0 mg.kg -1 / 3.8 to 1951.0 mg.kg -1 ), and La (30.6 to 253.0 mg.kg -1 / 12.1 to 517.0 mg.kg -1 ). The other REEs presented concentrations of between the detection limit and 46.0 mg.kg -1 . The results indicate that the Ce, La, and Nd concentrations appeared in up to 12 times the average occurrences in the earth's crust and up to 4.6 times higher than the averages reported in studies worldwide, including Brazil. Therefore, further studies are warranted to examine the economic viability of REEs in the area and to confirm the occurrence of these anomalous elements in the studied region. (author)

  8. Video processing of remote sensor data applied to uranium exploration in Wyoming. [Roll-front U deposits

    Energy Technology Data Exchange (ETDEWEB)

    Levinson, R.A.; Marrs, R.W.; Crockell, F.

    1979-06-30

    LANDSAT satellite imagery and aerial photography can be used to map areas of altered sandstone associated with roll-front uranium deposits. Image data must be enhanced so that alteration spectral contrasts can be seen, and video image processing is a fast, low-cost, and efficient tool. For LANDSAT data, the 7/4 ratio produces the best enhancement of altered sandstone. The 6/4 ratio is most effective for color infrared aerial photography. Geochemical and mineralogical associations occur in unaltered, altered, and ore roll-front zones. Samples from Pumpkin Buttes show that iron is the primary coloring agent which makes alteration visually detectable. Eh and pH changes associated with passage of a roll front cause oxidation of magnetite and pyrite to hematite, goethite, and limonite in the host sandstone, thereby producing the alteration. Statistical analysis show that the detectability of geochemical and color zonation in host sands is weakened by soil-forming processes. Alteration can only be mapped in areas of thin soil cover and moderate to sparse vegetative cover.

  9. Uranium loans

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    When NUEXCO was organized in 1968, its founders conceived of a business based on uranium loans. The concept was relatively straightforward; those who found themselves with excess supplies of uranium would deposit those excesses in NUEXCO's open-quotes bank,close quotes and those who found themselves temporarily short of uranium could borrow from the bank. The borrower would pay interest based on the quantity of uranium borrowed and the duration of the loan, and the bank would collect the interest, deduct its service fee for arranging the loan, and pay the balance to those whose deposits were borrowed. In fact, the original plan was to call the firm Nuclear Bank Corporation, until it was discovered that using the word open-quotes Bankclose quotes in the name would subject the firm to various US banking regulations. Thus, Nuclear Bank Corporation became Nuclear Exchange Corporation, which was later shortened to NUEXCO. Neither the nuclear fuel market nor NUEXCO's business developed quite as its founders had anticipated. From almost the very beginning, the brokerage of uranium purchases and sales became a more significant activity for NUEXCO than arranging uranium loans. Nevertheless, loan transactions have played an important role in the international nuclear fuel market, requiring the development of special knowledge and commercial techniques

  10. The evaluation of in-situ leaching hydrological-geologic condition in a sandstone-type uranium deposits of a low-grade and thick ledge

    International Nuclear Information System (INIS)

    Jiang Yan

    2014-01-01

    The ore aquifer of a sandstone-type uranium deposits is thick, the grade, and uranium amount per square meter is low. To demonstrate the economic rationality of the in-situ leaching deposit, the Pumping test on the spot, recovery of water levels test, Pumping test and Injection test, Injection test in a Drilling hole, the pumping and injection balance test are carried out. And the hydro geological parameters of mineral aquifer are acquired. The parameters includes coefficient of transmissibility, Coefficient of permeability, Specific discharge of a well and Water injection. Radius of influence etc. The relation between discharge of drilling and Drawdown is researched. The capability of pumping and injection by a drilling hole is determined. The Hydraulic between the aquifer with mineral and the upper and lower aquifer is researched. The reasonable Mining drawdown is testified, the hydrogeological conditions of in-Situ leaching of the mining deposit is found out, this provides necessary parameters and basis for this kind of Situ-leach uranium mining wells, the designing of Spacing of wells, and the economic evaluation of In-situ leaching technology. (author)

  11. Study on exploration theory and SAR technology for interlayer oxidation zone sandstone type uranium deposit and its application in Eastern Jungar Basin

    International Nuclear Information System (INIS)

    Pan Wei; Liu Dechang; Rui Benshan; Zhao Yingjun; Huang Xianfang; Huang Shutao

    2001-01-01

    Started with analyzing the features of metallogenetic epoch and space distribution of typical interlayer oxidation zone sandstone type uranium deposit both in China and abroad and their relations of basin evolution, the authors have proposed the idea that the last unconformity mainly controls the metallogenetic epoch and the strength of structure activity after the last unconformity determines the deposit space. An exploration theory with the kernel from new events to the old one is put forward. The means and method to use SAR technology to identify ore-controlling key factors are discussed. An application study in Eastern Jungar Basin is performed

  12. The opportunities for uranium development in South Australia

    International Nuclear Information System (INIS)

    Jackson, N.

    1979-07-01

    The opportunities for uranium development in South Australia are discussed. The author outlines the likely development of three known uranium deposits, shows the world energy and uranium requirements and makes some observations on uranium enrichment

  13. Surficial and applied surficial geology of the Belchertown Quadrangle, Massachusetts

    Science.gov (United States)

    Caggiano, Joseph A.

    1977-01-01

    Till and stratified drift overlie maturely dissected topography in the Belchertown quadrangle, an area that straddles the New England Upland and Connecticut Valley Lowland in central Massachusetts. Lower Paleozoic, massive quartzo-feldspathic gneiss, quartzite and schist of the Pelham dome and Devonian granodiorite and quartz diorite of the Belchertown intrusive complex are in contact with Triassic arkosic fanglomerate and basalt along a lengthy normal fault separating the New England Upland from the Connecticut Valley Lowland. The orientation of striae, roches moutonnees, and streamline ridges indicate that the last Wisconsinian glacier advanced generally south 12? east. This glacier removed several meters of rock from the upland and an unknown larger quantity from the preglacial valley of the Connecticut River. Till is thin in the uplands, but several tens of feet of drift overlie bedrock in the lowland. Three lithic facies of sandy, clast-rich, non-compact, subarkosic till derived from the three major source rocks rest on bedrock or on highly weathered, compact, clast-poor, fissile probably older till. The mean for all upper till is 69.6% sand, 21.7% silt, and 8.8% clay; lower till consists of 48% sand, 23% silt and 29% clay. Mud-rich, compact, sparsely stony till in drumlins in and along the flank of the Connecticut Valley Lowland is composed of 51.5% sand, 28% silt, and 20.5% clay. Upper tills are facies equivalent deposits of the youngest Wisconsinian drift. Lower till is compact deeply weathered, jointed and stained suggesting it is correlative with other lower till in New England deposited by an earlier Wisconsinian glacier. Drumlin till may be a facies equivalent of a lower till or a mud-rich upper till derived from earlier glaciolacustrine deposits. Upper and lower till of the Belchertown quadrangle is texturally similar to other New England upper and lower tills to which they are equivalent. Both tills are interpreted as lodgment till derived from

  14. Uranium isotopes as radioactive pollutants in groundwaters of the Morro do Ferro thorium deposit, Brazil

    International Nuclear Information System (INIS)

    Bonotto, D.M.

    1991-01-01

    Groundwater and surface water samples were collected at Morro do Ferro, a thorium and rare earth deposit located on the Pocos de Caldas Plateau, Minas Gerais State, Brazil, to evaluate if the mechanisms related to the migration of 238 U and 234 U isotopes can generate concentrations greater than the gross-alpha activity contaminant limit. The 238 U content range was 0.003-0.24 pCi/1 and the 234 U content range was 0.004-0.25 pCi/1, showing that the studied hydrologic environment doesn't indicate pollution by radioactivity due to these nuclides. However, 226 Ra and 228 Ra isotopes can be considered as radioactive pollutants in groundwaters but not in surface waters of the Morro do Ferro. (author)

  15. Discussion on some problems concerned the origin of hydrothermal uranium deposit from the point of remelting in situ view

    International Nuclear Information System (INIS)

    Zhang Ke

    2001-01-01

    The authors try to discuss some problems concerned the origin of hydrothermal uranium (U) deposit from the point of remelting in situ view about granite formation. The problems include the time differences between mineralization and country rock (granite), characteristics, differences between 'large granite bodies' and 'small granite bodies', granite discriminant that is used to judge whether or not granite produce U deposit as well as relationship of U mineralization to W(Sn), Nd, Ta mineralization, red beds and tectonic movements. According to the theory of remelting in situ, granite bodies in the same period that can be investigated are actual doming portions of the same remelting layer, which had be so stripped by erosion that granite bodies rustled. Thus the size variation of granite bodies implies only the fact of different erosion levels. Since U always moves in long distance with hydrothermal solution from its parent granite, it always deposits in outer contact zone, which, as a kind of country rock, might be sedimentary rock (including red bed), metamorphic rock, of early period granite. The two former situations indicate less erosion levels (small granite bodies) while the later situation indicates larger erosion levels (large granite bodies). Because the country rock of later is granite, an illusion of large time difference between mineralization related granite and granite might be made. Also, there is no direct and simple connection between U mineralization and discriminant which is calculated from primary chemical composition of granite and has been unsuccessfully used as an index to judge whether of not a granite body would produce U mineralization because in this situation the granite is only country rock. Besides, the U mineralization is later than the one of W(Sn), Nd, Ta in general so that it often relate to 'large granite bodies', in which 'mineralization crust' is lower than the one of W(Sn), Nd, Ta and mineral composition is relatively simple