Hostname: page-component-77c89778f8-m8s7h Total loading time: 0 Render date: 2024-07-20T16:31:11.026Z Has data issue: false hasContentIssue false
  • English
  • Français

Magnesian ilmenite in picritic basalts from the Karoo Province, South Africa

Published online by Cambridge University Press:  05 July 2018

R. Grant Cawthorn ,
John W. Bristow  and
David I. Groves
R. Grant Cawthorn
Affiliation:
Geology Department, University of the Witwatersrand, Wits, 2050, South Africa
John W. Bristow
Affiliation:
Geology Department, De Beers Consolidated Mines, Box 47, Kimberley, 8300, South Africa
David I. Groves
Affiliation:
Geology Department, University of Western Australia, Nedlands, 6009, Australia
Get access Rights & Permissions [Opens in a new window]

Abstract

Some picritic lavas from near the base of the volcanic succession in the Lebombo region of the Karoo Province contain phenocrysts of olivine and skeletal microphenocrysts of ilmenite, the latter indicating rapid crystallization from the magma. These ilmenite grains contain up to 6% MgO. The near-liquidus crystallization and the high MgO content of the ilmenite are highly anomalous for ilmenite in tholeiitic rocks. These features reflect the atypical nature (high MgO and TiO2) of the parental magma and/or highly reduced conditions of crystallization.

Keywords

magnesian ilmeniteilmenitebasaltsKaroo ProvinceSouth Africa
Type
Research Article
Information
Mineralogical Magazine , Volume 53 , Issue 370 , April 1989 , pp. 245 - 252
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1989

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bishop, F. C. (1980) Am. J. Sci. 280, 46-77.CrossRefGoogle Scholar
Bowles, J. F. W. (in press) Am. Mineral. Google Scholar
Bristow, J. W. (1984) Spec. Publ. Geol, Sac. S. Aft. 13, 105-23.Google Scholar
Bristow, J. W. and Cleverly, R. W. (1983) Trans. Geol. Sac. S. Afr. 86, 55-61.Google Scholar
Bristow, J. W. and Cleverly, R. W. and Saggerson, E. P. (1983) Bull. Volcanol. 46, 135-59.CrossRefGoogle Scholar
Cawthorn, R. G., Groves, D. L. and Marchant, T. (1985) Can. Mineral. 23, 609-18.Google Scholar
Cawthorn, R. G., Groves, D. L. and Marchant, T., Maske, S., De Wet, M., Groves, D. I. and Cassidy, K. F. (1988) Ibid. 26Google Scholar
Cox, K. G. (1983) In Continental Basalts and Mantle Xenoliths (Hawkesworth, C. J. and Norry, M. J., eds.) Shiva Publishers, 139-57.Google Scholar
Cox, K. G. and Jamieson, B. G. (1974) J. Petrol. 15, 269-302.CrossRefGoogle Scholar
Dowset, J. S. and Reid, N. T. (1967) Trans. Geol. Sac. S. Afr. 70, 67-79.Google Scholar
Drever, H. I. and Johnston, R. (1957) Trans. Roy. Sac. Edin. 63, 289-315.CrossRefGoogle Scholar
Duncan, A. R., Erland, A. J. and Marsh, J. S. (1984) Geol. Sac. S. Aft. Spec. Pub. 13, 355-88.Google Scholar
Eales, H. V. and Marsh, J. S. (1979) S. Afr. J. Sci. 75, 400-4.Google Scholar
Eales, H. V. and Marsh, J. S., Reynolds, I. M. and Gouws, D. A. (1981) Trans. Geol. Soc. S. Afr. 83, 243-53.Google Scholar
Eales, H. V. and Marsh, J. S., Marsh, J. S. and Cox, K. G. (1984) Geol. Soc. S. Aft. Spec. Pub. 13, 1-26.Google Scholar
Frondel, J. W. (1975) Lunar Mineralogy. John Wiley and Sons.Google Scholar
Groves, D. I., Marchant, T., Maske, S. and Cawthorne, R.G, (1986) Econ. Geol. 81, 725-31.CrossRefGoogle Scholar
Haggerty, S. E. (1973) Proc. Lunar Sci. Conf. 4th, Houston, 777-97.Google Scholar
Haggerty, S. E. (1976) In Oxide Minerals (Rumble, D., ed.) Min. Soc. Am. Hgl01-300.Google Scholar
Haggerty, S. E. and Tompkins, L. A. (1984) In Kimberlites—l: Kimberlites and related rocks (Kornprobst, J., ed.). Elsevier, Amsterdam, 335-58.CrossRefGoogle Scholar
Le Roex, A. P. and Reid, D. L. (1978) Contrib. Mineral. Petrol. 66, 351-60.CrossRefGoogle Scholar
Lighffoot, P. C. and Naldrett, A. J. (1984) Can. Mineral. 22, 111-23.Google Scholar
Lighffoot, P. C. and Naldrett, A. J. and Hawkesworth, C. J. (1984) Econ. Geol. 79, 1857-79.CrossRefGoogle Scholar
Lighffoot, P. C. and Naldrett, A. J. and Hawkesworth, C. J. (1987) Can. Mineral. 25, 79-90.Google Scholar
Lipman, P. W. (1971) J. Geol. 79, 438-56.CrossRefGoogle Scholar
Mitchel, R. H. (1973) Ibid. 81, 301-11.Google Scholar
Reynokls, I. M. (1983) Trans. Geol. Soc. S. Afr. 86, 211-20.Google Scholar
Scboltz, D. L. (1936) Ibid. 39, 81-210.Google Scholar
Shee, S. R. (1984) In Kimberlites—l: Kimberlites and related rocks (Kornprobst, J., ed.). Elsevier, Amsterdam, 59–74.CrossRefGoogle Scholar
Thompson, R. N. (1976) Mineral. Mag. 40, 857-2.CrossRefGoogle Scholar
Tischler, S. E., Cawthorn, R. G., Kingston, G. A. and Maske, S. (1981) Can. Mineral. 19, 607-18.Google Scholar
Usselman, T. M. and Lofgren, G. E. (1976) Proc. Lunar. Sci. Conf. 7th, Houston, Texas, 1345-63.Google Scholar
Von Knorring, O. and Cox, K. G. (1961) Mineral. Mag. 32, 676-82.Google Scholar
Walker, D., Kirkpatrick, R. J., Longhi, J. and Hays, J. F. (1976) Bull. Geol. Soc. Am. 87, 646-56.2.0.CO;2>CrossRefGoogle Scholar
Walker, D., Kirkpatrick, R. J., Longhi, J. and Hays, J. F., Shibata, T. and Delong, S. E. (1979) Contrib. Mineral. Petrol. 70, 111-25.CrossRefGoogle Scholar
Walker, F. and Poldervaart, A. (1949) Bull. Geol. Soc. Am. 60, 591-706. Google Scholar
Woermann, E., Hirschberg, A. and Lamprecht, A. (1969) Fortsch. Miner. 49, 79-80.Google Scholar