1887
Volume 23, Issue 1-2
  • ISSN: 0812-3985
  • E-ISSN: 1834-7533

Abstract

Published examples show that the palaeomagnetic method may furnish constraints upon the timing of a mineralisation for a variety of ore-deposits. Success of the palaeomagnetic method relies upon:

1. Knowledge of the apparent polar wander path (APWP) for the continent or terrane in which the deposit occurs.

2. Crystallisation of new magnetic minerals in a deposit or its wall-rocks during a principal phase of mineralisation, constituting a magnetisation event.

3. Duration of the mineralisation event having been sufficiently long to average palaeosecular variation of the Earth’s magnetic field.

4. The ore deposit having a sufficiently isotropic magnetic fabric to record accurately the Earth’s magnetic field direction.

5. Knowledge of the history of tectonic disturbance of the mineral deposit.

6. A lack of complete alteration of the magnetic phases, leading to total palaeomagnetic overprinting in a later, and different, magnetic field-direction.

Even when a number of these requirements for dating are not met, the palaeomagnetic method still has the potential to discriminate syngenetic from epigenetic mineralisation or provide a minimum estimate of mineralisation-age. By sampling both the ore deposit and the country rocks surrounding the zone of mineral alteration, it can be established whether the two have comparable or different magnetisation histories. The former relationship characterises a syngenetic deposit; the latter an epigenetic deposit. In the case of total remagnetisation of an ore, only a minimum mineralisation age can be estimated from the remagnetisation direction.

The usefulness and precision of the palaeomagnetic method varies from continent to continent and with mineralisation age. In favourable circumstances, a precision of within half a geological period is estimated during Phanerozoic times. Precision generally decreases with increasing mineralisation age. Potential applications of the method to Western Australian base-metal and iron-ore deposits serve to illustrate the dependence of the method on (i) the density of existing palaeomagnetic data and (ii) the rate and course of APW at the approximate time of mineralisation.

© 1992 ASEG
Loading

Article metrics loading...

/content/journals/10.1071/EG992373
1992-03-01
2026-01-25

  • From This Site

    /content/journals/10.1071/EG992373
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Bachtadse, V, and Briden, J. C. (1991). ‘Palaeomagnetism of Devonian ring complexes from the Bayuda Desert, Sudan — new constraints on the apparent polar wander path for Gondwanaland’. Geophys. J. Int.104, 635–646.
  2. Bachtadse, V, Van der Voo, R., Haynes, F. M., and Kesler, S. E. (1987). ‘Late Palaeozoic magnetisation of mineralised and unmineralised Ordovician carbonates from East Tennessee: Evidence for a post-ore chemical event’. J. Geophys. Res., 92, 14165–14176.
  3. Beales, F. W., Carracedo, J. C., and Strangway, D. W. (1974). ‘Palaeomagnetism and origin of Mississippi Valley-Type ore deposits’. Can. J. Earth Sci.11, 211–223.
  4. Browning, T. D., and Beske-Diehl, S. (1987). ‘Palaeomagnetism and the age of copper mineralization in the Portage Lake Volcanics, Upper Peninsula, Michigan’. Can. J. Earth Sci.24, 2396–2404.
  5. Byrne, D. R., and Harris, L. B. (1992). ‘Structural control on the base metal vein deposits of the Northampton Complex, Western Australia’. Ore Geol. Rev., in press.
  6. Chamalaun, F. H., and Dempsey, C. E. (1978). ‘Palaeomagnetism of the Gawler Range Volcanics and implications for the genesis of the Middleback hematite ore bodies’. J. Geol. Soc. Aust.25, 255–265.
  7. Clark, D. A., and Schmidt, P. W. (1986a). ‘Magnetic properties of the banded-iron-formations of the Hamersley Group, W.A’. CSIRO Restricted Investigation Report 1638R.
  8. Clark, D. A., and Schmidt, P. W. (1986b). ‘Geological structure and magnetic signatures of Hamersley BIF’s’. CSIRO Restricted Investigation Report 1639R.
  9. Cogne, J. P. (1988). ‘Strain-induced AMS in the granite of Flamanville and its effects upon TRM acquisition’. Geophys. J.92, 445–453.
  10. Embleton, B. J. J., and Schmidt, P. W. (1985). ‘Age and significance of magnetisations in dolerite dykes from the Northampton Block, Western Australia’. Aust. J. Earth Sci.32, 279–286.
  11. Evans, A. M., and El-Nikhely, A. (1982a). ‘Some palaeomagnetic dates from the West Cumbrian hematite deposits, England’. Trans. Inst. Min. Metall. B 91, 41–43.
  12. Evans, A. M., and El-Nikhely, A. (1982b). ‘Palaeomagnetic age for mineralization at Auchenstilloch. Lanarkshire, Scotland’. Trans. Inst. Min. Metall. B 91, 43–44.
  13. Evans, A. M., and Evans, N. D. M. (1977). ‘Some preliminary palaeomagnetic studies of mineralisation in the Mendip orefield’. Trans. Inst. Min. Metall. B 86, 149–151.
  14. Gronlie, A., and Torsvik, T. H. (1989). ‘On the origin of hydrothermal thorium-enriched carbonate veins and breccias in the More-Trondelag Fault Zone, Central Norway’. Norsk Geologiske Tidssskrift69, 1–19.
  15. Gutmanis, J. C., Hailwood, E. A., Maddock, R. H., and Vita-Finzi, C. (1991). ‘The use of dating techniques to constrain the age of fault activity: a case history from north Somerset, United Kingdom’. Q. J. Eng. Geol.24, 363–374.
  16. Hanus, V., and Krs, M. (1963). ‘Palaeomagnetic dating of hydrothermal deposits in Czechoslovakia’. Geophys. J. Roy. astron Soc.8, 82–101.
  17. Harmsworth, R. A., Kneeshaw, M., Morris, R. C., Robinson, C. J., and Shrivastava, P. K. (1990). ‘BIF-derived iron ores of the Hamersley Province’. In F. E. Hughes (ed.), Geology of the Mineral Deposits of Australia and Papua New Guinea, pp. 617–642. Aust. Inst. Min. Metall., Melbourne.
  18. Idnurm, M. (1985). ‘Late Mesozoic and Cenozoic palaeomagnetism of Australia — I. A redetermined apparent polar wander path’. Geophys. J. Roy. astron. Soc.83, 399–418.
  19. Idnurm, M., and Giddings, J. W. (1988). ‘Australian Precambrian polar wander: A review’. Precamb. Res.40/41, 61–88.
  20. Irving, E. A. (1979). ‘Palaeopoles and palaeolatitudes of North America and speculations about displaced terrains’. Can. J. Earth Sci.15, 669–694.
  21. Jowett, E. C., Pearce, G. W., and Rydzewski, A. (1987). ‘A mid-Triassic palaeomagnetic age of the Kupferscheifer mineralisation in Poland, based on a revised apparent polar wander path for Europe and Russia’. J. Geophys. Res.92, 581–598.
  22. Krs, M., and Stovichova, N. (1966). ‘Palaeomagnetic investigation of hydrothermal deposits in the Jachymov (Joachimsthal) Region, Western Bohemia’. Trans. Inst. Min. Metall.75, 51–57.
  23. Li, Z. X., Powell, C. McA., Thrupp, G. A., and Schmidt, P. W. (1990). ‘Australian Palaeozoic palaeomagnetism and tectonics II: A revised apparent polar wander path and palaeogeography’. J. struct. Geol.12, 567–577.
  24. Li, Z. X., Powell, C. McA., and Trench, A. (1992). ‘Palaeozoic global reconstructions’. In J. Long (ed), Palaeozoic Vertebrates, Belhaven Press, London, in press.
  25. Lowrie, W., Hirt, A. M., and Kligfield, R. (1986). ‘Effects of tectonic deformation on the remanent magnetisation of rocks’. Tectonics5, 713–722.
  26. McElhinny, M. W. (1973). ‘Palaeomagnetism and plate tectonics’. Cambridge University Press, Cambridge, 358pp.
  27. McFadden, P. L. (1977). ‘A palaeomagnetic determination of the emplacement temperature of some South African kimberlites’. Geophys. J. Roy. astron. Soc.50, 587–604.
  28. McFadden, P. L., and Jones, D. L. (1977). ‘The palaeomagnetism of some Upper Cretaceous kimberlite occurrences in South Africa’. Earth Plan. Sci. Lett.34, 125–135.
  29. McWilliams, M. O. (1981). ‘Palaeomagnetism and Precambrian tectonic evolution of Gondwana’. In A. Kroner (ed.), Precambrian Plate Tectonics. Elsevier Publishing Co. Amsterdam, 649–687.
  30. Morris, W. A. (1980). ‘Tectonic and metamorphic history of the Sudbury norite: the evidence from palaeomagnetism’. Econ. Geol.75, 260–277.
  31. Morris, W. A. (1981). ‘Intrusive and tectonic history of the Sudbury micropegmatite: The evidence from palaeomagnetism’. Econ. Geol.76, 791–804.
  32. Morris, W. A., and Pay, R. (1981). ‘Genesis of the Foy (?) Offset and its sulphide ores: the palaeomagnetic evidence from a study in Hess Township, Sudbury, Ontario’. Econ. Geol.76, 1895–1905.
  33. Mory, A. J., and Dunn, P. R. (1990). ‘Bonaparte, Canning, Ord and Officer Basins — Regional geology and mineralisation. In Geology of the mineral deposits of Australia and Papua New Guinea (ed. F.E.Hughes), pp. 1089-1096. Austr. Inst. Min. Metall., Melbourne.
  34. Pan, H., Symons, D. T. A., and Sangster, D. F. (1990). ‘Palaeomagnetism of the Mississippi Valley-Type ores and host rocks in the Northern Arkansas and Tri-state districts’. Can. J. Earth Sci.27, 923–931.
  35. Parry, W. T., and Geissman, J. W. (1991). ‘Palaeomagnetic test of the age of gold mineralisation in the Mercur district, Utah’. EOS, Trans. Amer. Geophys. Un. (Supplement), Fall meeting 1991 Program and Abstracts, p.144.
  36. Personen, L. J., Torsvik, T. H., Elming, S. A., and Bylund, G. (1989). ‘Crustal evolution of Fennoscandia — palaeomagnetic constraints’. Tectonophysics162, 27–49.
  37. Porath, H., and Chamaulaun, F. H. (1968). ‘Palaeomagnetism of Australian hematite ore bodies — II, Western Australia’. Geophys. J. Roy. astron. Soc.15, 253–264.
  38. Refai, E., Wassif, N. A., and Shoaib, A. (1989). ‘Stability of remanence and palaeomagnetic studies of some chromite ores from Barramiya and Allawi occurrences, Eastern Desert, Egypt.’ Earth Plan. Sci. Lett.94, 151–159.
  39. Sangster, D. F. (1986). ‘Age of mineralisation in Mississippi Valley-Type (MVT) deposits: a critical requirement for genetic modelling’. In C. J. Andrew, R. W. A. Crowe, S. Finlay, W. M. Penell and J. F. Pyne (eds), Geology and Genesis of Mineral Deposits in Ireland, 625-634. Irish Association for Economic Geology.
  40. Sverjensky, D. A. (1986). ‘Genesis of Mississippi Valley-Type lead-zinc deposits’. Ann. Rev. Earth Plan. Sci.14, 177–199.
  41. Symons, D. T. A., Quick, A. W., and Stupavsky, M. (1982). ‘Magnetic and palaeomagnetic characteristics of the Archaean Iron Formation and host rocks at the Adams Mine, Ontario’. Ontario Geol. Sunv. Misc. Paper98, 293–307.
  42. Symons, D. T. A., and Sangster, D. F. (1991a). ‘Palaeomagnetic age of the Central Missouri barite deposits and its genetic implications’. Econ. Geol.86, 1–12.
  43. Symons, D. T. A., and Sangster, D. F. (1991b). ‘Palaeomagnetism of the Central Mississippi Valley-Type (MVT) Ba-Pb-Zn deposits, USA: Showing that the mineralisation and magnetisation events are coeval’. IAGA XX General Assembly, Vienna, Program and Abstracts, p.152.
  44. Symons, D. T. A., and Sangster, D. F. (1992). ‘Late Devonian palaeomagnetic age for the Polaris Mississippi Valley-type Zn-Pb deposit, Canadian Arctic Archipelago.’ Can. J. Earth Sci.29, 15–25.
  45. Symons, D. T. A., and Stupavsky, M. (1980). ‘Magnetic anomaly type curves and palaeomagnetism of the Algoman-Type Iron Formation near Temagami, Ontario’. Ontario Geol. Surv. Misc. Paper93, 215–219.
  46. Symons, D. T. A., Walley, D. S., and Stupavsky, M. (1980). ‘Component magnetisation of the Algoman Iron Formation and host rocks, Moose Mountain Mine, Ontario’. Ontario Geol. Surv., Misc. Paper93, 198–214.
  47. Torsvik, T. H., Smethurst, M. A., Van der Voo, R., Trench, A., Abrahamsen, N., and Halvorsen, E. (1992b). ‘BALTICA — A synopsis of Vendian-Permian palaeomagnetic data and their palaeotectonic implications’. Earth Sci. Rev., in press.
  48. Torsvik, T. H., Sturt, B. A., Swensson, E., Andersen, T. B., and Dewey, J. F. (1992a). ‘Palaeomagnetic dating of fault rocks: evidence for Permian and Mesozoic movements and brittle deformation along the extensional Dalsfjord Fault, western Norway’. Geophys. J. Int.109, 565–580.
  49. Van der Voo, R. (1990). ‘Phanerozoic palaeomagnetic poles from Europe and North America and comparisons with continental reconstructions’. Rev. Geophys.28, 167–206.
  50. Van der Voo, R., and Meert, J. G. (1991). ‘Late Proterozoic palaeomagnetism and tectonic models: a critical appraisal’. Precamb. Res.53, 149–163.
  51. Wisniowiecki, M. J., Van der Voo, R., McCabe, C,, and Kelly, W. C. (1983). ‘A Pennsylvanian palaeomagnetic pole from the mineralised Late Cambrian Bonneterre Formation, southeast Missouri’. J. Geophys. Res.88, 6540–6548.
  52. Wu, Y., and Beales, F. W. (1981). ‘A reconnaissance study by palaeomagnetic methods of the age of mineralisation along the Viburnum Trend, southeast Missouri.’ Econ. Geol.76,1879–1894.
/content/journals/10.1071/EG992373
Loading
  • Article Type: Research Article

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