1887
Volume 32, Issue 3-4
  • ISSN: 0812-3985
  • E-ISSN: 1834-7533

Abstract

In the Eastern Goldfields of Western Australia, airborne electromagnetic (AEM) data have been acquired over areas prospective for nickeliferous laterite deposits, although their application in exploring for this style of mineralisation is not well understood. In part, this can be attributed to a lack of detail concerning relationships between supergene Ni enrichment and the petrophysical, particularly electrical, properties associated with prospective regolith materials and settings. This issue was addressed using a combination of multi-parameter borehole geophysical techniques and laboratory analyses of mineralogy, geochemistry and soluble salt content for 24 drill holes in a zone of known mineralisation associated with the Cawse lateritic Ni deposits, located in the Eastern Goldfields, W.A.

The regolith associated with supergene Ni enrichment exhibited a complex vertical conductivity structure. In places, elevated conductivities were coincident with Ni-Mn-Co mineralisation. These correlations were noted to occur at hydromorphic barriers associated with structural discontinuities, or in places where regolith textural changes were marked. A better understanding of the complex spatial patterns associated with the electrical character of the regolith at Cawse, was achieved by examining the weathered profile as a set of hydrostratigraphic units, namely the transported cover, zone of illuviation and in situ regolith. This framework allows the observed regolith electrical structure to be explained in terms of contemporary groundwater processes and the accumulation of soluble salts.

The observed petrophysical (electrical) response of the regolith at Cawse suggests that AEM has a role in locating impermeable barriers and faults which may, respectively, represent sites for shallow, high grade Mn-Co-Ni and garnierite mineralisation, particularly where they are coincident with local accumulations of soluble salt and moisture.

© 2001 ASEG
Loading

Article metrics loading...

/content/journals/10.1071/EG01160
2001-09-01
2026-01-20

  • From This Site

    /content/journals/10.1071/EG01160
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Brand, N.W., Butt, C.R.M., and Hellsten, K.J., 1996, Structural and lithological controls in the formation of the Cawse nickel laterite deposits, Western Australia-Implications for supergene ore formation and exploration in deeply weathered terrains. Nickel '96. Conference Proc. Kalgoorlie, Nov. 1996, Aus IMM, Pub.No. 6/96, 185-190.
  2. Brand, N.W., 1997, Chemical and mineralogical characteristics of weathered komatiitic rocks, Yilgarn Craton, W.A.: Discrimination of nickel sulphide bearing and barren komatiites, University of Western Australia, PhD Thesis.
  3. Brand, N.W., Butt, C.R.M., and Elias, M., 1998, Nickel laterites: classification and features. AGSO Journal of Australian Geology and Geophysics, 17(4), 81-88.
  4. Clark, R.N., 1999. Spectroscopy of rocks and minerals, and principles of spectroscopy. IN: Rencz, A.N. (Ed.), Remote Sensing for the Earth Sciences. Manual of Remote Sensing (3rd. Ed.), 3. John Wiley and Sons, Inc., NY. 672pp.
  5. Commander, D.P., Fifield, L.K., Thorpe, P.M., Davie, R.F., Bird, J.R. and Turner, J.V., 1994, Chlorine-36 and carbon-14 measurements on hypersaline groundwater in Tertiary palaeochannels near Kalgoorlie, WesternAustralia: Geological Survey of Western Australia, Professional papers, Report 37.
  6. Denn, S., 1999, Cawse lateritic nickel deposit, Centre for teaching and research in strategic mineral deposits, Department of Geology and Geophysics, The University of Western Australia, p.1-20.
  7. Dickson, B.L. and Scott, K.M., 1989, Radioelements in weathered shales and mafic volcanics, Panglo gold deposit, Eastern Goldfields, WA. CSIRO Division of Exploration Geoscience, Restricted Report, 41R.
  8. Elias, M., Donaldson, M.J., Giorgetta, N., 1981, Geology, mineralogy, and chemistry of lateritic nickel-cobalt deposits near Kalgoorlie, Western Australia, Economic Geology, 76, 1775-1783
  9. Gozzard, J.R., Munday, T.J., Hunter, W.M., and Gabell, A.R., 1992, An evaluation of spot panchromatic imagery as an aid to regolith-landform mapping in the Ora Banda Area, Eastern Goldfields Province, WA restricted Report, 233R. CSIRO Australia, Division of Exploration and Mining, Perth, p 6-10.
  10. Hingston, F.J., and Gailitis, V., 1976, The geographic variation of salt precipitated over Western Australia: Australian Journal of Soil Research, 14, 319-335.
  11. Johnston, C.D., 1987a, Distribution of environmental chloride in relation to subsurface hydrology, in Hydrology and salinity in the Collie River Basin, Western Australia edited by A. J. PECK and D. R. WILLIAMSON: Journal of Hydrology, 94, Special Issue, no. 1/2, 67-88.
  12. Johnston, C.D., 1987b, Preferred water flow and localised recharge in a variable regolith, in Hydrology and salinity in the Collie River Basin, Western Australia edited by A. J. PECK and D. R. WILLIAMSON: Journal of Hydrology, 94, Special; Issue, no. 1/2, 129-142.
  13. Kern, A.M., 1995, Hydrogeology of the Kalgoorlie 1:250000 sheet, Geological Survey of Western Australia, 1:250 000 Hydrogeological Series Explanatory Notes, 16p.
  14. Lane, R., Green, A., Golding, C., Owers, M., Pik, P., Plunkett, C., Sattel, S. and Thorn, B., 2000, An example of 3D conductivity mapping using the TEMPEST airborne electromagnetic system: Exploration Geophysics, 31, 162-172.
  15. Lawrence, L., 1999, Geochemistry of nickel in the regolith, 1999, in Nickel Laterites, Centre for teaching and research in strategic mineral deposits, Department of Geology and Geophysics, The University of Western Australia, p.1-12.
  16. Loftus-Hills, G.D., 1975, Ora Banda lateritic nickel deposits, W.A., In: C.L., Knight (Editor), Economic Geology of Australia and Papua New Guinea, Australian Institute of Mining and Metallurgy, Melbourne, pp. 1010-1011.
  17. McArthur, J.M., Turner, J.V., Lyons, W.B., and Thirwall, M.F., 1989, Salt sources and water rock interaction on theYilgarn Block, Australia, isotopic and major element tracers, Applied Geochemistry, 4, 79-92.
  18. Mullins, C.E., 1977, Magnetic susceptibility of the soil and its significance in soil science: A review, Journal of Soil Science, 28, 223-246.
  19. Munday, T.J. and Sumpton, J., 1999, Regolith electrical structures associated with kimberlite dykes - an example from the Archaean Yilgarn Craton, Western Australia, Proc. South African Geophysical Assoc. 6th Biannual Conference, 13pp.
  20. Munday, T.J., Macnae, J., Bishop, J., and Sattel, D., 2001, A geological interpretation of observed electrical structures in the regolith: Lawlers, Western Australia. Exploration Geophysics, 32, 36-47.
  21. Peric, M., 1981, Exploration of Burundi nickeliferous laterites by electrical methods. Geophysical Prospecting, 29, 274-287.
  22. Rayment, G.E., and Higginson, F.R., 1992, Australian Laboratory Handbook of Soil and Water Chemical methods, Inkata Press, Melbourne, 330pp.
  23. Pontual, S., Merry, N., and Cocks, T., 1995, Field-based Alteration Mapping Using the PIMA, PACRIM '95., 6pp
  24. Rutherford, J.L., Munday, T.J., Cooper, M., Myers, J., 2001, Cawse Nickel Laterite Deposits: Observed relationships between regolith materials, Ni enrichment, hydrogeology and geophysical response, CSIRO Division of Exploration and Mining, Restricted Report 834R.
  25. Smith, B.H., 1977, Some aspects of the use of geochemistry in the search for nickel sulphides in lateritic terrain in Western Australia: Journal of Geochemical Exploration, 8, 259-281.
  26. Taylor, J.C., and Clapp, R.A., 1992, New features and advance applications of SIROQUANT, A personal computer ERD full profile quantitative analysis software package, Advances in X-ray Analysis, 35, 49-55.
  27. van de Graaff, W.J.E., Crowe, R.W.A., Bunting, J.A., and Jackson, M.J., 1977, Relict early Cainozoic drainages in arid Western Australia, Zeitschrift fur Geomorphologie N.F., 21, pt 4, p. 379-400.
  28. Witt, W.K., 1990, Geology of the Bardoc 1:100 000 sheet: Explanatory notes, Geological Survey of Western Australia, Record 1990/14.
/content/journals/10.1071/EG01160
Loading
  • Article Type: Research Article
Keyword(s): Cawse; conductivity; hydrogeology; Lateritic Ni-Co-Mn deposits; regolith petrophysics; Western Australia

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