1887
ASEG2003 - 16th Geophysical Conference
  • ISSN: 2202-0586
  • E-ISSN:

Abstract

A high resolution gravity traverse (27.2 km-long, 50 m or 100 m station-spacing) across the unconformity-associated McArthur River uranium deposit, Athabasca Basin, Canada was conducted to investigate basement geology and locate alteration zones related to mineralization. In this geological environment, amplitudes of gravity anomalies relevant to uranium exploration (related to offsets of the basement unconformity, basement relief and alteration zones) are typically ˂ 1 mGal, but range up to 2 mGal. Alteration near the McArthur River deposit is commonly present as silicification of the basin sandstones, located above basement quartzite units. Many short to intermediate wavelength (250-1800 m) anomalies, amplitudes ˂ 0.5 mGal, are identified along the traverse profile, superposed on longer wavelength and larger amplitude (up to 6000 m, and 1.8 mGal, respectively) anomalies. Preliminary modeling of anomalies, constrained by magnetic data, drill-hole logs and density information, and reflection seismic data, indicates a variety of geological contributions. Short wavelength anomalies are attributed to changes in thickness of the glacial overburden, thickening in some places being linked to preferential erosion along an underlying fault. Long wavelength anomalies are explained by variations in basement density and offsets of the basement unconformity. Importantly, from an exploration perspective, most intermediate wavelength positive anomalies are explained by a combination of silicification within the Athabasca Sandstone, and associated basement relief produced by underlying basement quartzite units. Desilicification is also modeled, but limited. The gravity method, apparently, has been successful in identifying alteration zones that may be of significant interest for uranium exploration, because of their association with mineralizing fluids, and because patterns of silicification/desilicification are important for studies of fluid flow.

© ASEG 2003
Loading

Article metrics loading...

/content/journals/10.1071/ASEG2003ab171
2003-08-01
2026-01-17

  • From This Site

    /content/journals/10.1071/ASEG2003ab171
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Annesley, I.R. and Madore, C, 1993, Laboratory measurements of magnetic susceptibility and density from lithological units of the Wollaston Domain, Saskatchewan: Saskatchewan Research Council Publication R-1230-11-C-93.
  2. Gyorfi, I., Hajnal, Z., Bernier, S., Takacs, E., Reilkoff, B., White, D., Powell, B., and Koch R., 2002, Initial seismic images along line 14 from the McArthur River high-resolution survey (Abstract): in Abstracts Volume 27, Geological Association of Canada - Mineralogical Association of Canada Joint Annual Meeting, Saskatoon, p. 43.
  3. Hajnal, Z., White, D.W., Reilkoff, B., Adam, E., Bellefleur, G., Koch, R., Powell, B., and Annesley, I.R., 2001, EXTECH IV sub-project 1: Seismic studies at the McArthur River mining camp: in Summary of Investigations 2001, volume 2, Saskatchewan Geological Survey, Saskatchewan Energy and Mines, Miscellaneous Report 2001-4.2, 199-203.
  4. Hasegawa, K, Davidson, G.I., Wollenberg, P., and Iida, Y., 1990, Geophysical exploration for unconformity-related uranium deposits in the northeastern part of the Thelon Basin, Northwest Territories, Canada: Mining Geology, 40, 83-94.
  5. Marlatt, J., McGill, B., Matthews, R., Sopuck, V., and Pollock, G., 1992, The discovery of the McArthur River uranium deposit, Saskatchewan, Canada: in New Developments in Uranium Exploration, Resources, Production and Demand. Proceedings of a Technical Committee Meeting jointly organized by the International Atomic Energy Agency and the Nuclear Energy Agency of the Organization for Economic Cooperation Development, Vienna, 26-29 August, 1991, IAEA-TECDOC-650, 118-127.
  6. Matthews, R., Koch, R., Leppin, M., Powell, B., and Sopuck, V., 1997, Advances in integrated exploration for unconformity uranium deposits in Western Canada: in Gubins, A.G. (ed.), Proceedings of Exploration 97: Fourth Decennial International Conference on Mineral Exploration, GEOF/X, 993-1001.
  7. McGill, B.D., Marlatt, J.L., Matthews, R.B., Sopuck, V.J., Homeniuk, L.A., and Hubregtse, J.J., 1993, The P2 North uranium deposit Saskatchewan, Canada: Exploration Mining Geology, 2, 321-331.
  8. McMullan, S.R., Matthews, R.B., and Robertshaw, P., 1987, Exploration geophysics for Athabasca uranium deposits: in Garland, G.D. (ed.), Proceedings of Exploration ‘87: Third Decennial International Conference on Geophysical and Geochemical Exploration for Minerals and Groundwater, Ontario Geological Survey, Special Volume 3, 547-566.
  9. Ramaekers, P., Yeo, G., and Jefferson, C, 2001, Preliminary overview of regional stratigraphy in the late Paleoproterozoic Athabasca Basin, Saskatchewan and Alberta: in Summary of Investigations 2001, volume 2, Saskatchewan Geological Survey, Saskatchewan Energy and Mines, Miscellaneous Report 2001-4.2, 240-251.
  10. Thomas, D.J., Jefferson, C.W., Yeo, G.M, Card, C, and. Sopuck, V.J., 2002, I. Introduction: in Andrade, N., Breton, G., Jefferson, C.W., Thomas, D.J., Tourigny, G., Wilson, S., and Yeo, G.M. (eds.), Field trip Al. The eastern Athabasca Basin and its uranium deposits, Geological Association of Canada/Mineralogical Association of Canada.
/content/journals/10.1071/ASEG2003ab171
Loading
  • Article Type: Research Article
Keyword(s): exploration; gravity; modelling; silicification; uranium

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error