Structural Studies on the Uranium Deposit of the Fay Mine, Eldorado, Northwest Saskatchewan

1972 ◽  
Vol 9 (7) ◽  
pp. 803-823 ◽  
Author(s):  
R. D. Morton ◽  
G. P. Sassano
Keyword(s):  
Uranium Deposit ◽  
Regional Metamorphism ◽  
Local Deformation ◽  
Structural Studies ◽  
Long Period ◽  
Northern Saskatchewan

The Fay Mine uranium deposit is composed of veins parallel to the foliation of the paragneisses and paraschists of the Fay Mine Complex, which in turn overlies the Donaldson Lake Gneiss and Foot Bay Gneiss, within the Tazin Group of the Beaverlodge District, northern Saskatchewan. A computer oriented study of 5500 strike-dip measurements of planar features within the Fay Mine reveals that the lowest member of the metamorphic sequence, the Foot Bay Gneiss, is unique in that it exhibits Kenoran (?) structures associated with F1, NW-SE or N-S trending folds. Subsequent to the Kenoran (?) folding, an Aphebian (?) sequence of sediments and volcanics, now represented by the Donaldson Lake Gneiss and the Fay Mine Complex, was deposited. NE-SW trending, Hudsonian, F2 folds then developed and extensive cataclasis was effected. The F2 structures also affected the uppermost, taphrogeosynclinal Martin Formation sediments and volcanics. The major faults of the district are thought to have been initiated either as F2-shear joints or F2-tension fractures and have undergone multiple movement over a long period of time. The pitchblende ± quartz ± carbonates ± hematite ± chlorite veins, classified as 'mobilized stratabound deposits', occur parallel to S2 foliation planes in the crests, troughs, or limbs of F2 folds, wherever minimal plunge is observed. Such deposits may have been generated during regional metamorphism by mobilization of uranium-rich fractions from the originally uraniferous Aphebian precursors of the Fay Mine Complex. Later movement of such major structures as the St. Louis Fault has apparently caused only local deformation and brecciation of the uraniferous veins and has caused no more than limited recrystallization.

U–Pb geochronology of minerals from the Midwest uranium deposit, northern Saskatchewan

1984 ◽  
Vol 21 (6) ◽  
pp. 642-648 ◽  
Author(s):  
H. Baadsgaard ◽  
G. L. Cummino ◽  
J. M. Worden
Keyword(s):  
First Generation ◽  
Second Generation ◽  
Uranium Deposit ◽  
Paragenetic Sequence ◽  
Secondary Material ◽  
Basement Rocks ◽  
Northern Saskatchewan ◽  
Host Rocks ◽  
Sampling Problems ◽  
Late Stages

Analyses of U/Pb ratios in 30 microsamples of pitchblende and coffinite from the Midwest uranium deposit in northern Saskatchewan, as well as two altered zircons from host rocks, indicate an age of mineralization for primary pitchblende of 1328 ± 17 Ma. The primary material was remobilized at 1110 ± 28 Ma, forming the second generation of pitchblende and coffinite. First-generation pitchblende appears to have lost Pb either by diffusion or by a series of episodic losses at 300–100 Ma, whereas the secondary material proved more susceptible to Pb loss in the recent past.There is evidence of migration of pitchblende downwards into the basement rocks under the deposit at least as recently as 700 Ma ago, but we have been unable to date with certainty any late stages in the paragenetic sequence because of sampling problems associated with the small size of material clearly identifiable as stage 3 or 4 of the paragenetic sequence of Wray et al.

Ages of major uranium mineralization and lead loss in the Key Lake uranium deposit, northern Saskatchewan, Canada

1984 ◽  
Vol 79 (6) ◽  
pp. 1378-1386 ◽  
Author(s):  
Linda K. Trocki ◽  
David B. Curtis ◽  
Alexander J. Gancarz ◽  
Joseph C. Banar
Keyword(s):  
Uranium Deposit ◽  
Uranium Mineralization ◽  
Northern Saskatchewan

Isotopic studies of lead-depleted pitchblende, secondary radioactive minerals, and sulphides from the Rabbit Lake uranium deposit, Saskatchewan

1979 ◽  
Vol 16 (9) ◽  
pp. 1702-1715 ◽  
Author(s):  
G. L. Cumming ◽  
J. Rimsaite
Keyword(s):  
Electron Microprobe ◽  
Uranium Deposit ◽  
Uranium Mineralization ◽  
Polished Section ◽  
Radiogenic Lead ◽  
Isotopic Studies ◽  
Different Types ◽  
Northern Saskatchewan ◽  
Radioactive Minerals

Uranium–lead and lead isotopic studies have been made on different types of pitchblende, on secondary Pb-rich and Pb-poor uranium-bearing minerals, and on sulphides (radiogenic galena and pyrite) from the Rabbit Lake uranium deposit in northern Saskatchewan. Most specimens have been selected on the basis of their mineralogy and Pb/U ratios as determined by electron microprobe analyses. The Pb/U ratio varied between 1/2 and 1/665 as a result of diverse episodes of crystallization, differential losses of uranium and radiogenic lead, recrystallization of remobilized uranium and lead in different proportions in secondary radioactive minerals, and possible loss or enrichment of radon gas.All concentrates yielded discordant ages. Six samples contained an excess of radiogenic lead and yielded Pb/U ratios above the concordia curve. P-1 (primary) pitchblende samples were found to be depleted of radiogenic lead, thus grading into the Pb-depleted pitchblende of type P-2, and the data on even the "best" material can, thus, only be interpreted in terms of a discordia line which yields intersections at about 1281 and 440 Ma.A second discordia intersects the concordia curve at 1085 Ma and was obtained on concentrates containing several types of pitchblende including some samples difficult to distinguish in polished section from those of the 1281–440 Ma line, and secondary Pb-rich and Pb-poor uranyl-bearing aggregates that fell above, and at the lower end of, the concordia curve. This discordia intersection agrees well with previously published ages.The important event related to the replacement of pitchblende by sulphides, selenides, and arsenides, accompanied by marked losses of radiogenic lead and mobilization of uranium from the partly-resorbed "primary" pitchblende of type P-1, took place at a time no greater than 800–900 Ma ago. Reactions between remobilized uranium and altered silicates, and between the uranium and silica to form uraniferous phyllosilicates and coffinite, occurred 440 and ca. 200 Ma ago. Crystallization of hydrous uranyl-bearing aggregates, including precipitation of amorphous crusts in fractures of argillized rocks, continues at the present time.The Rabbit Lake deposit has been affected by superimposed alterations and recurring fracturing leaving fragments of partly resorbed and Pb-depleted pitchblende as the only remnants of the original intensive and widespread uranium mineralization.

An interpretation of surface and borehole seismic surveys for mine planning at the Millennium uranium deposit, northern Saskatchewan, Canada

Geophysics ◽  
2012 ◽  
Vol 77 (5) ◽  
pp. WC203-WC212 ◽  
Author(s):  
Garnet Wood ◽  
Clare O’Dowd ◽  
Calin Cosma ◽  
Nicoleta Enescu
Keyword(s):  
Uranium Deposit ◽  
Mine Planning ◽  
Athabasca Basin ◽  
Seismic Surveys ◽  
Vertical Seismic Profiling ◽  
Surface Survey ◽  
Northern Saskatchewan ◽  
Hydrogeologic Setting ◽  
Mine Development ◽  
Borehole Seismic

The Millennium uranium deposit is located within the Athabasca Basin, in northern Saskatchewan, Canada. The deposit is hosted within moderately dipping Paleoproterozoic gneisses that are unconformably overlain by more than 500 m of flat lying, porous Paleoproterozoic to late Mesoproterozoic Athabasca Group sandstones. The deposit is associated with the sandstone-basement unconformity, post-Athabasca structure, and hydrothermal alteration. These features combine to create a complex 3D hydrogeologic setting that presents challenges with respect to mine development, production, and safety. In 2007, as part of a prefeasibility study for potential mine development, a seismic program consisting of a 3D surface survey, vertical seismic profiling, moving source profiling, and side-scan surveys was undertaken to map the complex geology. The geometry and resolution of these different seismic surveys allowed for direct imaging of the geologic targets of interest, regardless of orientation and size. After integration with drill-defined geology, the program successfully imaged the location and character of the unconformity, the post-Athabasca structural setting at camp and deposit scales, and the alteration around the deposit. This information increased the understanding of geotechnical aspects of the geology hosting the deposit, and is currently being used to help minimize risk and costs associated with mine development. Seismic surveys are now viewed as an integral part of risk reduction associated with mining in the Athabasca Basin.

On nearly-commensurable periods in the restricted problem of three bodies, with calculations of the long-period variations in the interior 2:1 case

1966 ◽  
Vol 25 ◽  
pp. 197-222 ◽  
Author(s):  
P. J. Message
Keyword(s):  
Periodic Solution ◽  
Periodic Solutions ◽  
Large Amplitude ◽  
Restricted Problem ◽  
Small Amplitude ◽  
Minor Planets ◽  
Long Period ◽  
Numerical Integrations ◽  
Period Variations ◽  
The Mean

An analytical discussion of that case of motion in the restricted problem, in which the mean motions of the infinitesimal, and smaller-massed, bodies about the larger one are nearly in the ratio of two small integers displays the existence of a series of periodic solutions which, for commensurabilities of the typep+ 1:p, includes solutions of Poincaré'sdeuxième sortewhen the commensurability is very close, and of thepremière sortewhen it is less close. A linear treatment of the long-period variations of the elements, valid for motions in which the elements remain close to a particular periodic solution of this type, shows the continuity of near-commensurable motion with other motion, and some of the properties of long-period librations of small amplitude.To extend the investigation to other types of motion near commensurability, numerical integrations of the equations for the long-period variations of the elements were carried out for the 2:1 interior case (of which the planet 108 “Hecuba” is an example) to survey those motions in which the eccentricity takes values less than 0·1. An investigation of the effect of the large amplitude perturbations near commensurability on a distribution of minor planets, which is originally uniform over mean motion, shows a “draining off” effect from the vicinity of exact commensurability of a magnitude large enough to account for the observed gap in the distribution at the 2:1 commensurability.

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