Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-20T03:44:55.807Z Has data issue: false hasContentIssue false

Perovskite from the Dutoitspan kimberlite, Kimberley, South Africa: implications for magmatic processes

Published online by Cambridge University Press:  05 July 2018

R. C. Ogilvie-Harris*
Affiliation:
Department of Earth Science, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, UK
M. Field
Affiliation:
Department of Earth Science, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, UK
R. S. J. Sparks
Affiliation:
Department of Earth Science, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, UK
M. J. Walter
Affiliation:
Department of Earth Science, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, UK
*

Abstract

Perovskite compositions are used to investigate the relationship between the minor components (i.e. LREE, Fe3+ and Nb) and the oxygen fugacity (fo2) of perovskite in four different kimberlite lithofacies from the Dutoitspan pipe, Kimberley, South Africa, which range from diamondiferous to barren. The perovskite textures and chemical variations provide insight into magmatic and eruptive processes. Some crystals display cores with rims separated by a sharp boundary. The cores contain larger Na and LREE contents relative to the rims, which show a large increase in Fe3+ and Al. The mid-grade and barren kimberlites have bi-modal cores, reflected in the mineral chemistry, signifying multiple batches of magma and magma mixing. The fo2 of the magma is determined by an Fe-Nb oxygen barometer. The most diamondiferous kimberlite has the greatest Fe3+ content and highest fo2 (NNO –3.6 to –1.1). The kimberlite containing large diamonds has the smallest Fe3+ content and lowest fo2 (NNO –5.2 to –3.0). The barren and mid-grade kimberlites display a wide range of fo2,(NNO –5.3 to –1.5) as a result of perovskites forming in different melts and subsequently mixing together. Chemical and petrological evidence suggests that the volatile content, degassing, decompression and rate of crystallization can influence the rate at which the magma is erupted. One possibility is that the most oxidized magma, containing the highest volatile content, is therefore erupted much more rapidly, preserving diamond as a consequence.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2009

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

Anderson, A.T. (1976) Magma mixing: Petrological process and volcanological tool. Journal of Volcanology and Geothermal Research, 1, 333.CrossRefGoogle Scholar
Arima, M. (1998) Experimental study of growth and resorption of diamond in kimberlite melts at high pressures and temperatures. Pp. 32—34 in: Extended Abstracts of the 7th International Kimberlite Conference, Cape Town, RSA.Google Scholar
Ballhaus, C. and Frost, B.R. (1994) The generation of oxidized CO2-bearing basaltic melts from reduced CI-Lt-bearing upper mantle sources. Geochimica et Cosmochimica Ada, 62, 329331.Google Scholar
Baswick, A.E. and Carmichael, I.S.E. (1978) Constraints on mantle source composition imposed by phosphorus and rare-earth elements. Contributions to Mineralogy and Petrology, 67, 317330.CrossRefGoogle Scholar
Bellis, A.J. and Canil, D. (2007) Ferric iron in CaTiO3perovskite in as an oxygen barometer for kimberlite magmas I: Experimental Calibration. Journal of Petrology, 48, 219230.CrossRefGoogle Scholar
Boctor, N.Z. and Boyd, F.R. (1980) Oxide minerals in the Liqhobong kimberlite, Lesotho. American Mineralogist, 65, 631638.Google Scholar
Brown, R.J., Buse, B., Sparks, R.S.J. and Field, M. (2008) On the welding of pyroclasts from very low viscosity magmas: examples from kimberlite volcanoes. Journal of Geology, 116, 354374.CrossRefGoogle Scholar
Candela, P.A. (1997) A review of shallow, ore-related granites: textures, volatiles, and ore metals. Journal of Petrology, 38, 16191633.CrossRefGoogle Scholar
Canil, D. and Bellis, A.J. (2007) Ferric iron in CaTiO3perovskite as an oxygen barometer for kimberlite magmas II: applications. Journal of Petrology, 48, 231252.CrossRefGoogle Scholar
Carmichael, I.S.E. and Ghiorso, M.S. (1986) Oxidation—reduction relations in basic magma: a case for homogeneous equilibria. Earth and Planetary Science Letters, 78, 200210.CrossRefGoogle Scholar
Carmichael, I.S.E. and Nicholls, J. (1967) Iron-titanium oxides and oxygen fugacities in volcanic rocks. Journal of Geophysical Research, 72, 46654687.CrossRefGoogle Scholar
Chakhmouradian, A.R. and Mitchell, R.H. (1998) A structural study of the perovskite series CaTii. 2xFexNbxO3 . Journal of Solid State Chemistry, 138, 272277.CrossRefGoogle Scholar
Chakhmouradian, A.R. and Mitchell, R.H. (2000) Occurrence, alteration patterns and compositional variation of perovskite in kimberlites. The Canadian Mineralogist, 38, 975994.CrossRefGoogle Scholar
Chakhmouradian, A.R. and Mitchell, R.H. (2001) Three compositional varieties of perovskite from kimberlites of the Lac de Gras field (Northwest Territories, Canada). Mineralogical Magazine, 65, 133148.CrossRefGoogle Scholar
Clement, C.R. (1982) A comparative geological study of some major kimberlite pipes in the Northern Cape and Orange Free State. Ph.D. thesis, University of Cape Town, RSA.Google Scholar
Cortes, J.A., Wilson, M., Condliffe, E. and Francalanci, L. (2006) The occurrence of forsterite and highly oxidizing conditions in basaltic lavas from Stromboli Volcano, Italy. Journal of Petrology, 47, 13451373.CrossRefGoogle Scholar
Davies, G.R. and Lloyd, F.E. (1989) Pb-Sr-Nd isotope and trace element data bearing on the origin of the potassic subcontinental lithosphere beneath South West Uganda. Pp. 784794 in: Kimberlites and related rocks, vol 2., Special Publication 14, Geological Society of Australia.Google Scholar
Eccles, D.R., Heaman, L.M., Luth, R.W. and Creaser, R.A. (2004) Petrogenesis of the late Cretaceous northern Alberta kimberlite province. Lithos, 76, 435459.CrossRefGoogle Scholar
Fedortchouk, Y. and Canil, D. (2004) Intensive variables in kimberlite magmas, Lac de Gras, Canada and implications for diamond survival. Journal of Petrology, 45, 17251745.CrossRefGoogle Scholar
Fedortchouk, Y., Canil, D. and Carlson, J.A. (2005) Dissolution forms in Lac de Gras diamonds and their relationship to the temperature and redox state of kimberlite magma. Contributions to Mineralogy and Petrology, 150, 5469.CrossRefGoogle Scholar
Fedortchouk, Y., Canil, D. and Semenets, E. (2007) Mechanisms of diamond oxidation and their bearing on the fluid composition in kimberlite magmas. American Mineralogist, 92, 12001212.CrossRefGoogle Scholar
Field, M., Stiefenhofer, J., Robey, J.A. and Kurszlaukis, S. (2008) The kimberlite-hosted diamond deposits of southern Africa: A review. Ore Geology Reviews, 34, 3375.CrossRefGoogle Scholar
J.W., Harris and E.R., Vance (1974) Studies of the reaction between diamond and heated kimberlite. Contributions to Mineralogy and Petrology, 47, 237244.Google Scholar
Jones, A.P. and Wyllie, P.J. (1984) Minor elements in perovskites from kimberlites and the distribution of the rare earth elements. Earth and Planetary Science Letters, 69, 128140.CrossRefGoogle Scholar
Kjarsgaard, B.A., Pearson, D.G., Tappe, S., Nowell, G.M. and Dowall, D.P. (2008) Kimberlites: High H2O/CO2, MgO-rich, Al- and K-poor silica under-saturated magmas. 9th International Kimberlite Conference Extended Abstract No. 91KC-A-00197. Google Scholar
Luhr, J.F. and Carmichael, I.S.E. (1980) The Colima volcanic complex, Mexico I. Post-caldera andesites from Volcan Colima. Contributions to Mineralogy and Petrology, 71, 343372.CrossRefGoogle Scholar
Mitchell, R.H. (1972) Composition of perovskite in kimberlite. American Mineralogist, 57, 17481753.Google Scholar
Mitchell, R.H. (1973) Composition of olivine, silica activity and oxygen fugacity in kimberlite. Lithos, 6, 6581.CrossRefGoogle Scholar
Mitchell, R.H. (1986) Kimberlites: Mineralogy, Geochemistry and Petrology. Plenum, New York. 464 pp.CrossRefGoogle Scholar
Mitchell, R.H. (1996) Perovskites: a revised classification scheme for an important rare earth element host in alkaline rocks. Pp. 41—76 in: Rare Earth Minerals: Chemistry, origin and ore deposits (Jones, A.P., Wall, F. and Williams, C. T., editors). Chapman & Hall, London.Google Scholar
Mitchell, R.H. (2002) Perovskites Modern and Ancient. Almarez Press, Thunder Bay, Ontario, Canada, 314 pp.Google Scholar
Mitchell, R.H. (2008) Petrology of hypabyssal kimberlites: Relevance to primary magma compositions. Journal of Volcanology and Geothermal Research, 174, 18.CrossRefGoogle Scholar
Mitchell, R.H. and Reed, S.J.B. (1988) Ion microprobe determination of rare earth elements in perovskite from kimberlites and alnoites. Mineralogical Magazine, 52, 331339.CrossRefGoogle Scholar
Pasteris, J.D. (1983) Spinel zonation in the De Beers kimberlite, South Africa: possible role of phlogopite. Canadian Mineralogy, 21, 4158.Google Scholar
Roeder, P.L. and Schulze, D.J. (2008) Crystallization of groundmass spinel in kimberlite. Journal of Petrology, 49, 14731495.CrossRefGoogle Scholar
Skinner, E.M.W. and Clement, C.R. (1979) Mineralogical classification of Southern African kimberlites. Pp. 129139 in: Proceedings of 2nd International Kimberlite Conference (Boyd, F. R. and Meyer, H.A.O., editors). American Geophysical Union, Washington, D.C. Google Scholar
Sparks, R.S.J. and Pinkerton, H. (1978) Effect of degassing on rheology of basaltic lava. Nature, 276, 385386.CrossRefGoogle Scholar
Sparks, R.S.J., Baker, L., Brown, R.J., Field, M., Schumacher, J., Stripp, G. and Walters, A. (2006) Dynamical constraints on kimberlite volcanism. Journal of Volcanology and Geothermal Research, 155, 1848.CrossRefGoogle Scholar
Sparks, R.S.J., Brooker, R.A., Field, M., Kavanagh, J., Schumacher, J.C., Walter, MJ. and White, J. (2009) The nature of erupting kimberlite melts. Lithos, 112 (Suppl. 1), 4, 29438.Google Scholar
Turner, J.S. and Campbell, I.H. (1986) Convection and mixing in magma chambers. Earth Science Reviews, 23, 255352.CrossRefGoogle Scholar
Upton, B.G.J., Craven, J.A. and Kirstein, L.A. (2006) Crystallization of mela-aillikites of the Narsaq region, Gardar alkaline province, South Greenland and relationships to other aillikitic-carbonatitic associations in the province. Lithos, 92, 300319.CrossRefGoogle Scholar
Wyllie, PJ. (1980) The origin of kimberlite. Journal of Geophysical Research, 85, 69026910.CrossRefGoogle Scholar
Yang, Y., Wu, F., Wilde, S.A., Liu, X., Zhang, Y., Xie, L. and Yang, J. (2009) In situ perovskite Sr-Nd isotopic constraints on the petrogenesis of the Ordovician Mengyin kimberlites in the North China craton. Chemical Geology, 264, 2442.CrossRefGoogle Scholar