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Tinderet volcano, Kenya: an altered natrocarbonatite locality?

Published online by Cambridge University Press:  05 July 2018

A. N. Zaitsev*
Affiliation:
Department of Mineralogy, Faculty of Geology, St Petersburg State University, University Emb. 7/9, St Petersburg 199034, Russia Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK
T. Wenzel
Affiliation:
Fachbereich Geowissenschaften, Universität Tübingen, Wilhelmstr. 56, Tübingen 72074, Germany
T. Vennemann
Affiliation:
Institute of Earth Sciences, University of Lausanne, Géopolis, CH-1015 Lausanne, Switzerland
G. Markl
Affiliation:
Fachbereich Geowissenschaften, Universität Tübingen, Wilhelmstr. 56, Tübingen 72074, Germany

Abstract

The Tinderet volcano (19.9 to 5.5 Ma), located within the Kavirondo rift in Kenya, contains blocks of carbonatite lavas with calcite, minor apatite, fluorite, spinel-group minerals, accessory perovskite and 'plumbopyrochlore'; nyerereite is present as inclusions in the perovskite. At least four types of calcite are present in the carbonatite lavas; they differ in morphology, composition and origin. The dominant variety is secondary type-II calcite, which is enriched in sodium (up to 1.1 wt.% Na2O) and strontium (up to 1.3 wt.% SrO). The spinel-group minerals are manganese-bearing and include Mn-rich magnetite, magnesioferrite and jacobsite. Oxygen isotope data for bulk carbonatite samples (δ18O = +16.2 % to +22.6 % VSMOW) support a low crystallization temperature for the secondary calcite. Petrographic, mineralogical and isotopic data indicate that the Tinderet carbonatites are similar to natrocarbonatites from the Oldoinyo Lengai and Kerimasi volcanoes that have altered and recrystallized to form calcite carbonatites. These data support the hypothesis that some of the Tinderet carbonatites were originally alkali-rich rocks which contained primary nyerereite.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2013

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References

Bailey, D.K. (1993) Carbonate magmas. Journal of the Geological Society, 150, 637651.CrossRefGoogle Scholar
Bailey, D.K. and Kearns, S. (2002) High-Ti magnetite in some fine-grained carbonatites and the magmatic implications. Mineralogical Magazine, 66, 379384.CrossRefGoogle Scholar
Bailey, K. Garson, M. Kearns, S. and Velasco, A.P. (2005) Carbonate volcanism in Calatrava, central Spain: a report on the initial findings. Mineralogical Magazine, 69, 907915.CrossRefGoogle Scholar
Baker, B.H., Williams, L.A.J., Miller, J.A. and Fitch F.J. (1971) Sequence and geochronology of the Kenya rift volcanics. Tectonophysics, 11, 191215.CrossRefGoogle Scholar
Christy, A.G. and Atencio, D. (2013) Clarification of status of species in the pyrochlore supergroup. Mineralogical Magazine, 77, 1320.CrossRefGoogle Scholar
Church, A.A. (1995) The petrology of the Kerimasi Carbonatite Volcano and the carbonatites of Oldoinyo Lengai with a review of other occurrences of extrusive carbonatites. Unpublished PhD thesis, University of London, London, 384 pp.Google Scholar
Clark, M.G.C. and Roberts, B. (1986) Carbonated melilitites and calcitized alkali carbonatites from Homa Mountain, western Kenya: a reinterpretation. Geological Magazine, 123, 683692.CrossRefGoogle Scholar
Dawson, J.B. (1962) The geology of Oldoinyo Lengai. Bulletin Volcanologique, 24, 348387.CrossRefGoogle Scholar
Dawson, J.B. (1993) A supposed sövite from Oldoinyo Lengai, Tanzania: result of extreme alteration of alkali carbonatite lava. Mineralogical Magazine, 57, 93101.CrossRefGoogle Scholar
Dawson, J.B. (2008) The Gregory Rift Valley and Neogene–Recent Volcanoes of Northern Tanzania. Memoir of the Geological Society of London, 33. The Geological Society, London, 102 pp.Google Scholar
Dawson, J.B., Garson, M.S. and Roberts, D. (1987) Altered former alkalic carbonatite lava from Oldoinyo Lengai, Tanzania: inferences for calcite carbonatite lavas. Geology, 15, 765768.2.0.CO;2>CrossRefGoogle Scholar
Deans, T. and Roberts, B. (1984) Carbonatite tuffs and lava clasts of the Tinderet foothills, western Kenya: a study of calcified natrocarbonatites. Journal of the Geological Society, London, 141, 563580.CrossRefGoogle Scholar
Genge, M.J., Balme, M. and Jones, A.P. (2001) Saltbearing fumarole deposits in the summit crater of Oldoinyo Lengai, Northern Tanzania: interactions between natrocarbonatite lava and meteoric water. Journal of Volcanology and Geothermal Research, 106, 111122.CrossRefGoogle Scholar
Gittins, J. (1989) The origin and evolution of carbonatites magmas. Pp. 580600. in: Carbonatites: Genesis and Evolution (Bell, K., editor). Unwin Hyman, London.Google Scholar
Gittins, J. and Harmer, R.E. (1997) Dawson’s Oldoinyo Lengai calciocarbonatite: a magmatic sövite or an extremely altered natrocarbonatite? Mineralogical Magazine, 61, 351355.Google Scholar
Gittins, J. and Jago, B.C. (1991) Extrusive carbonatites: their origins reappraised in the light of new experimental data. Geological Magazine, 128, 301305.CrossRefGoogle Scholar
Guzmics, T., Mitchell, R.H., Szabo, C., Berkesi, M., Milke, R. and Ratter, K. (2012) Liquid immiscibility between silicate, carbonate and sulfide melts in melt inclusions hosted in co-precipitated minerals from Kerimasi volcano (Tanzania): evolution of carbonated nephelinitic magma. Contributions to Mineralogy and Petrology, 164, 101122.CrossRefGoogle Scholar
Hay, R.L. (1983) Natrocarbonatite tephra of Kerimasi volcano, Tanzania. Geology, 11, 599602.2.0.CO;2>CrossRefGoogle Scholar
Hay, R.L. (1986) Role of tephra in the preservation of fossils in Cenozoic deposits of East Africa. Geological Soci e ty of London, Special Publications, 25, 339344.CrossRefGoogle Scholar
Keller, J. and Krafft, M. (1990) Effusive natrocarbonatite activity of Oldoinyo Lengai, June 1988. Bulletin of Volcanology, 52, 629645.CrossRefGoogle Scholar
Keller, J. and Zaitsev, A.N. (2006) Calciocarbonatite dykes at Oldoinyo Lengai, Tanzania: the fate of natrocarbonatite. The Canadian Mineralogist, 44, 857876.CrossRefGoogle Scholar
King, B.C. and Chapman, G.R. (1972) Volcanism of the Kenya Rift Valley. Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 271, 185208.Google Scholar
King, B.C., Le Bas, M.J. and Sutherland, D.S. (1972) The history of the alkaline volcanoes and intrusive complexes of eastern Uganda and western Kenya. Journal of the Geological Society, 128, 173205.CrossRefGoogle Scholar
Kjarsgaard, B.A. and Mitchell, R.H. (2008) Solubility of Ta in the system CaCO3–Ca(OH)2–NaTaO3– NaNbO3 – F at 0.1 GPa: implications for the crystallization of pyrochlore-group minerals in carbonatites. The Canadian Mineralogist, 46, 981990.CrossRefGoogle Scholar
Kogarko, L.N., Plant, D.A. and Henderson, C.M.B. (1991) Na-rich carbonate inclusions in perovskite and calzirtite from the Guli intrusive Ca-carbonatite, polar Siberia. Contributions to Mineralogy and Petrology, 109, 124129.CrossRefGoogle Scholar
Le Bas, M.J. (1989) Diversification of carbonatites. Pp. 428447. in: Carbonatites: Genesis and Evolution (Bell, K., editor). Unwin Hyman, London.Google Scholar
Le Bas, M.J. and Dixon, J.A. (1965) A new carbonatite in the Lagetet Hills, Kenya. Nature, 207, 68.Google Scholar
Mariano, A.N. and Roeder, P.L. (1983) Kerimasi: a neglected carbonatite volcano. Journal of Geology, 91, 449455.CrossRefGoogle Scholar
Mitchell, R.H. (2006a) An ephemeral pentasodium phosphate carbonate from natrocarbonatite lapilli, Oldoinyo Lengai, Tanzania. Mineralogical Magazine, 70, 211218.CrossRefGoogle Scholar
Mitchell, R.H. (2006b) Mineralogy of stalactites formed by subaerial weathering of natrocarbonatite hornitos at Oldoinyo Lengai, Tanzania. Mineralogical Magazine, 70, 437444.CrossRefGoogle Scholar
Mitchell, R.H. and Belton, F. (2004) Niocalite– cuspidine solid solution and manganoan monticellite from natrocarbonatite, Oldoinyo Lengai, Tanzania. Mineralogical Magazine, 68, 787799.CrossRefGoogle Scholar
Mitchell, R.H. and Belton, F. (2008) Cuspidine-sodalite natrocarbonatite from Oldoinyo Lengai, Tanzania: a novel hybrid carbonatite formed by assimilation of ijolite. Mineralogical Magazine, 72, 12611277.CrossRefGoogle Scholar
Ngwenya, B.T. and Bailey, D.K. (1990) Kaluwe carbonatite, Zambia: an alternative to natrocarbonatite. Journal of the Geological Society, London, 147, 213216.CrossRefGoogle Scholar
O’Neil, J.R., Clayton, R.N. and Mayeda, T.K. (1969) Oxygen isotope fractionation in divalent metal carbonates. Journal of Chemical Physics, 51, 55475558.CrossRefGoogle Scholar
Onuonga, I.O., Fallick, A.E. and Bowden, P. (1997) The recognition of meteoric-hydrothermal and supergene processes in volcanic carbonatites, Nyanza Rift, western Kenya, using carbon and oxygen isotopes. Journal of African Earth Sciences, 25, 103113.CrossRefGoogle Scholar
Peterson, T.D. (1990) Petrology and genesis of natrocarbonatite. Contributions to Mineralogy and Petrology, 105, 143155.CrossRefGoogle Scholar
Pickford, M. (1986) Sedimentation and fossil preservation in the Nyanza Rift System, Kenya. Geological Society of London, Special Publications, 25, 345362.CrossRefGoogle Scholar
Reguir, E.P., Chakhmouradian, A.R., Nalden, N.M., Yang, P. and Zaitsev, A.N. (2008) Early magmatic and reaction-induced trends in magnetite from the carbonatites of Kerimasi, Tanzania. The Canadian Mineralogist, 46, 879900.CrossRefGoogle Scholar
Rosatelli, G., Wall, F. and Le Bas, M.J. (2003) Potassic glass and calcite carbonatite in lapilli from extrusive carbonatites at Rangwa Caldera Complex, Kenya. Mineralogical Magazine, 67, 931955.CrossRefGoogle Scholar
Shackleton, R.M. (1950) A contribution to the geology of the Kavirondo Rift Valley. Quarterly Journal of the Geological Society, 106, 345392.CrossRefGoogle Scholar
Spoetl, C. and Vennemann, T.W. (2003) Continuousflow isotope ratio mass spectrometric analysis of carbonate minerals. Rapid Communications in Mass Spectrometry, 17, 10041006.CrossRefGoogle Scholar
Stoppa, F. and Principe, C. (1998) Eruption style and petrology of a new carbonatitic suite from the Mt. Vulture (Southern Italy): the Monticchio Lake Formation. Journal of Volcanology and Geothermal Research, 80, 137153.CrossRefGoogle Scholar
Stoppa, F., Woolley, A.R., Lloyd, F.E. and Eby, N. (2000) Carbonatite lapilli-bearing tuff and a dolomite carbonatite bomb from Murumuli crater, Katwe volcanic field, Uganda. Mineralogical Magazine, 64, 641650.CrossRefGoogle Scholar
Veksler, I.V., Nielsen, T.F.D. and Sokolov, S.V. (1998) Mineralogy of crystallized melt inclusions from Gardner and Kovdor ultramafic alkaline complexes: implications for carbonatite genesis. Journal of Petrology, 39, 20152031.CrossRefGoogle Scholar
Vinogradov, A.P., Kropotova, O.I. and Gerasimovsky, V.I. (1970) Isotopic carbon composition of carbonatites of East Africa. Geokhimiya, 6, 643646. [in Russian].Google Scholar
Vinogradov, A.P., Dontseva, E.I., Gerasimovskiy V.I. and Kuznetsova, L.D. (1971) Oxygen isotopic composition of carbonatites from the rift zones of East Africa. Geochemistry International, 8, 307317.Google Scholar
Williams, L.A.J. (1969) Volcanic associations in the Gregory Rift Valley, East Africa. Nature, 224, 6164.CrossRefGoogle Scholar
Woolley, A.R. (1969) Some aspects of fenitization with particular reference to Chilwa Island and Kangankunde, Malawi. Bulletin of the British Museum (Natural History), Mineralogy, 2, 189219.Google Scholar
Woolley, A.R. (2001) Alkaline Rocks and Carbonatites of the World. Part 3: Africa. 2001. The Geological Society, London, 372 pp.Google Scholar
Woolley, A.R. and Church, A.A. (2005) Extrusive carbonatites: a brief review. Lithos, 85, 114.CrossRefGoogle Scholar
Woolley, A.R., Barr, M.W.C., Din, V.K., Jones, G.C., Wall, F. and Williams, C.T. (1991) Extrusive carbonatites from the Uyaynah area, United Arab Emirates. Journal of Petrology, 32, 11431167.CrossRefGoogle Scholar
Zaitsev, A.N. (2010) Nyerereite from calcite carbonatite at the Kerimasi volcano, northern Tanzania. Geology of Ore Deposits, 52, 630640.CrossRefGoogle Scholar
Zaitsev, A.N. and Chakhmouradian, A.R. (2002) Calcite-amphibole-clinopyroxene rock from the Afrikanda Complex, Kola Peninsula, Russia; mineralogy and a possible link to carbonatites. II. Oxysalt minerals. The Canadian Mineralogist, 40, 103120.CrossRefGoogle Scholar
Zaitsev, A.N. and Keller, J. (2006) Mineralogical and chemical transformation of Oldoinyo Lengai natrocarbonatites, Tanzania. Lithos, 91, 191207.CrossRefGoogle Scholar
Zaitsev, A.N., Keller, J., Spratt, J., Perova, E.N. and Kearsley, A. (2008) Nyerereite-pirssonite-calciteshortite relationships in altered natrocarbonatites, Oldoinyo Lengai, Tanzania. The Canadian Mineralogist, 46, 843860.CrossRefGoogle Scholar
Zaitsev, A.N., Keller, J. and Billström, K. (2009) Isotopic composition of Sr, Nd, and Pb in pirssonite, shortite and calcite carbonatites from Oldoinyo Lengai volcano, Tanzania. Doklady Earth Sciences, 425, 302306.CrossRefGoogle Scholar
Zaitsev, A.N., Williams, C.T., Britvin, S.N., Kuznetsova, I.V., Spratt, J., Petrov, S.V. and Keller, J. (2010) Kerimasite, Ca3Zr2(Fe3+ 2 Si)O12, a new garnet from carbonatites of Kerimasi volcano and surrounding explosion craters, northern Tanzania. Mineralogical Magazine, 74, 841858.CrossRefGoogle Scholar