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A review of the geochronology of the Precambrian of Saskatchewan—some clues to uranium mineralization

Published online by Cambridge University Press:  05 July 2018

Keith Bell*
Affiliation:
Dept. of Geology, Carleton University, Ottawa, Ontario, Canada

Abstract

Assessment of available geochronological information, as well as new whole-rock Rb-Sr data from several granitoid rocks of Saskatchewan, shows a close relationship between magmatic-metamorphic events in the Hudsonian orogen and uranium mineralization. Most uranium deposits lie to the west of the Needle Falls Shear Zone and occur as either: (i) vein-type deposits or (ii) unconformity-type deposits close to the contact between the Athabasca sediments and their basement. At least two metamorphisms have affected the pre-Athabasca rocks: the Kenoran at about 2500 Ma ago, and the more pervasive ‘main’ Hudsonian event at 1740 Ma. A much younger thermal event (perhaps associated with uplift and cooling) at 1540 Ma is also indicated. The post-Kenoran K-Ar dates suggest prolonged thermal activity from about 1900 Ma through to about 1500 Ma ago. Granitoid events at 1870 Ma and 1740 Ma ago are outlined by both U-Pb zircon and Rb-Sr whole-rock isochron data. Whole-rock Rb-Sr data from the unmetamorphosed Athabasca sediments suggest an approximate depositional age of 1450±50 Ma, a figure that is consistent with the age of the underlying Hudsonian basement and the truncation of the sediments by the Cree Lake diabase dyke swarm at about 1200–1300 Ma ago. Although several episodes of uranium deposition have been documented, the main ones seem to have occurred at 1860 Ma (syngenetic uraninite in pegmatites), 1740 Ma (the Beaverlodge vein-type deposits) and between 1300 and 800 Ma (the epigenetic uranium of the unconformity-type deposits). Whereas the two earlier episodes can be correlated with periods of either magmatic or metamorphic activity, the late Proterozoic episodes cannot. The close agreement between the age of the Cree Lake dyke swarm and the late Proterozoic mineralization suggests that at about 1300 Ma ago possible hydrothermal activity from relatively deep-seated fractures may have been responsible for the solution and transportation of the uranium of the unconformity-type deposits. The period 1300 Ma to about 900 Ma, in other parts of the Canadian Shield, was a time of crustal rifting, basic magmatism, carbonatite activity, and intense deformation. Prior to the deposition of the Athabasca sediments uranium was concentrated by Hudsonian magmatic and metamorphic processes whereas subsequently, transportation and intermittent deposition of the unconformity-type deposits were related to fairly long-lived, low-temperature hydrothermal activity.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1981

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References

Beck, L. S. (1969). Uranium deposits of the Athabasca region, Saskatchewan. Sask. Dept. Mineral. Resources, Rept. 126, 140 pp.Google Scholar
Beck, L. S. (1970). Genesis of uranium in the Athabasca region and its significance in exploration. Can. Inst. Min. Trans. 73, 73-69.Google Scholar
Beck, L. S. (1977). History of uranium exploration in northern Saskatchewan with special reference to the changing ideas of metallogenesis. I. Uranium in Saskatchewan, Spec. Pub. Sask. Geol. Soc. No. 3, 3-10.Google Scholar
Bell, K. and Blenkinsop, J. (1980). Saskatchewan Shield Geochronology Project. In Summary of lnvestigations 1980. Sask. Geol. Surv. Misc. Rept. 80-4, 18.Google Scholar
Bell, K. and Macdonald, R. (in prep.). Geochronological calibration of the early Proterozoic (Hudsonian) cycle in Saskatchewan, Canada.Google Scholar
Burwash, R. A., Baadsgaard, H., and Peterman, Z. E, (t962). Precambrian K-Ar dates from the Western Canada sedimentary basin. J. Geophys. Res. 67, 67-25.Google Scholar
Camfield, P. A. and Gough, D. I. (1977). A possible Proterozoic plate boundary in North America. Can. J. Earth Sci. 14, 14-38.CrossRefGoogle Scholar
Cumming, G. L. and Rimsaite, J. (1979). Isotopic studies of lead-depleted pitchblende, secondary radioactive minerals and sulphides from the Rabbit Lake uranium deposit, Saskatchewan. Ibid. 16, 16-15.Google Scholar
Dahlkamp, F. J. (1977). Geologic appraisal of the Key Lake U-Ni deposits, northern Saskatchewan. Geol. Soc. Am. Prog. Abst. 9, 941.Google Scholar
Dunn, C. E. (1977) (editor). Uranium in Saskatchewan. Spec. Pub. Sask. Geol. Soc. No. 3, 396 pp.Google Scholar
Gancarz, A. J. (1979). Chronology of the Cluff Lake uranium deposit, Canada. (Abst.) International Uranium Symposium on the Pine Creek geosyncline N. T., Australia. Extended Abstracts, 91-4.Google Scholar
Hoeve, J. (1978). Classification of uranium deposits in Northern Saskatchewan. In Short course in uranium deposits: their mineralogy and origin. Short course handbook, Vol. 3. Min. Assoc. Can. 397-402.Google Scholar
Hoeve, J. and Sibbald, T. I. I. (1978). Uranium concentration related to the sub-Athabasca unconformity, Northern Saskatchewan, Canada. Ibid. 475-84.Google Scholar
Hoeve, J., Ramaekers, P. P., and Lewry, J. F. (1980). Athabasca basin unconformity-type uranium deposits: a special class of sandstone-type deposits? In Uranium in the Pine Creek geosyncline. Int. At. En. Agency, Vienna, 575-94.Google Scholar
Knipping, H. D. (1971). Geology and uranium metallogenesis, Wollaston Lake area, Saskatchewan (Abst.). Can. Inst. Min. Met. Bull. 64, 51.Google Scholar
Knipping, H. D. (1974). The concept of supergene versus hypogene emplacement of uranium at Rabbit lake, Saskatchewan, Canada. Int. At. En. Agency, Vienna. Paper Sm-186/38, 38-49.Google Scholar
Koeppel, V. (1968). Age and history of the uranium mineralization of the Beaverlodge area, Saskatchewan, Geol. Surv. Can., Paper 67-31, 111 pp.Google Scholar
Langford, F. F. (1974). Origin of Australian uranium deposits: a universal process that can be applied to deposits in Saskatchewan. I. Fuels: a geological appraisal. Spec. Pub. Sask. Geol. Soc. No. 2, 2-44.Google Scholar
Lewry, J. F. and Sibbald, T. L I. (1977). Variation in lithology and tectonometamorphic relationships in the Precambrian basement of northern Saskatchewan. Can. J. Earth Sci. 14, 14-67.Google Scholar
Lewry, J. F. (1979). A review of Pre-Athabasca basement geology in northern Saskatchewan. I. Uranium Exploration Techniques. Spec. Pub. Sask. Geol. Soc. No. 4, 4-58.Google Scholar
Lewry, J. F. and Rees, C. J. (1978). Metamorphic patterns and their relation to tectonism and phitonism in the Churchill Province in Northern Saskatchewan. I. Metamorphism in the Canadian Shield. Geol. Surv. Can. Paper 78-10, 10-54.Google Scholar
Little, H. W. (1974). Uranium in Canada. Rept. of Activities. Part. A, Ibid. Paper 74-1. 137-9.CrossRefGoogle Scholar
Macdonald, R. and Broughton, P. (1980) (compilers). Geological Map of Saskatchewan. Prov. edit. 1:1000000. Saskatchewan Geological Survey.Google Scholar
Munday, R. J. (1978). Uranium mineralization in northern Saskatchewan (Abst.. Can. Inst. Min. Met. Bull. 71, 76.Google Scholar
Pagel, M. (1975). Détermination des conditions physicochemiques de la silicification diagénétiques des gres Athabasca (Canada) au moyen des inclusions fiuides. C. R. Acad. Sci. Paris, 280, Sér. D, 2301-4.Google Scholar
Ramaekers, P. P. (1979). Stratigraphy of the Athabasca Basin. I. Summary of Investigations 1979. Sask. Geol. Survey, Misc. Rept. 79-10, 10-60.Google Scholar
Ramaekers, P. P. and Dunn, C. E. (1977). Geology and geochemistry of the eastern margin of the Athabasca basin. I. Uranium in Saskatchewan. Spec. Pub. Sask. Geol. Soc. No. 3, 3-322.Google Scholar
Ray, G. E. and Wanless, R. K. (1980). The age and geological history of the Wollaston, Peter Lake and Rottenstone domains in northern Saskatchewan. Can. J. Earth Sci. 17, 17-47.CrossRefGoogle Scholar
Rimsaite, J. (1978). Application of mineralogy to the study of multi-stage mineralization in remobilized uranium deposits, Saskatchewan. I. Short course in uranium deposits: their mineralogy and origin. Short course handbook. Min. Assoc. Can. Vol. 3, 3-30.Google Scholar
Robinson, S. C. (1955). Mineralogy of uranium deposits, Goldfields, Saskatchewan. Geol. Surv. Can. Bull. 31, 128 pp.Google Scholar
Sassano, G. P., Fritz, P., and Morton, R. D. (1972). Paragenesis and isotopic composition of some gangue minerals from the uranium deposits of Eldorado, Saskatchewan. Can. J. Earth Sci. 9, 9-57.CrossRefGoogle Scholar
Sassano, G. P., Baadsgaard, H., and Burwash, R. A. (1974). Rb-Sr age of the late-kinematic phase of the Hudsonian Orogeny in the Beaverlodge area, Saskatchewan. Ibid. 11, 11-9.Google Scholar
Steiger, R. and Jäger, E. (1977). Subcommission on geochronology: convention on the use of decay constants in geo- and cosmochronology. Earth Planet. Sci. Lett. 36, 36-62.CrossRefGoogle Scholar
Tremblay, L. P. (1958). Geology and uranium deposits of Beaverlodge region, Saskatchewan, U.N. 2nd Int. Conf. Peaceful Uses of At. Energy. Geneva, 2, 49–17.Google Scholar
Tremblay, L. P. (1970). The significance of uranium in quartzite in the Beavedodge area, Saskatchewan. Can. J. Earth Sci. 7, 7-305.CrossRefGoogle Scholar
Tremblay, L. P. (1972). Geology of the Beaverlodge mining area, Saskatchewan. Geol. Surv. Can. Mere. 367.CrossRefGoogle Scholar
Tremblay, L. P. (1978). Geologic setting of the Beaverlodge-type of vein uranium deposit and its comparison to that of the unconformity-type. In Short course on uranium deposits: their mineralogy and origin. Short course handbook. Vol. 3, Min. Assoc. Can. 431-56.Google Scholar
Wanless, R. K., Stevens, R. D., Lachance, C. R., and Delabio, R. N. (1974). Age determinations and geological studies, K-Ar isotopic ages. Rept. 11. Geol. Surv. Can. Paper 73-2, 139 pp.Google Scholar
Wendt, I., Hohndorf, A., Lenz, H., and Voultsidis, V. (1978). Radiometric age determinations on samples of Key Lake uranium deposits. I. Short Paper of the Fourth Int. Conf. Geochronology, Cosmochronology, Isotope Geology, 1978. U.S. Geol. Surv. Open File Rept. 78-701, 701-9.Google Scholar