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Growth of zircon and titanite during metamorphism in the granitoid-gneiss terrane south of the Barberton greenstone belt, South Africa

Published online by Cambridge University Press:  05 July 2018

A. Dziggel*
Affiliation:
Economic Geology Research Institute, University of the Witwatersrand, Private Bag 3, PO Wits 2050, Johannesburg, South Africa
R. A. Armstrong
Affiliation:
Research School for Earth Sciences, The Australian National University, Canberra, ACT 0200, Australia
G. Stevens
Affiliation:
Department of Geology, University of Stellenbosch, Matieland, 7140, Stellenbosch, South Africa
L. Nasdala
Affiliation:
Institut für Geowissenschaften — Mineralogie, Johannes Gutenberg-Universität, D-55099 Mainz, Germany

Abstract

SHRIMP U-Pb zircon and titanite dating have been used to constrain the timing of mid- to lower- crustal metamorphism (∼650—700°C and 8—11 kbar) and syn-kinematic melting in the granitoid gneiss- dominated terrane south of the Barberton greenstone belt, South Africa. This study is concentrated on a clastic metasedimentary unit exposed in one of several greenstone remnants and a late-kinematic trondhjemite intrusive into spatially associated mixed gneisses. Locally, the clastic metasediments show extensive replacement of garnet and plagioclase by epidote and titanite. The titanites yield an upper intercept date of 3229±9 Ma, and provide a minimum age for the peak of metamorphism. Zircons separated from the same unit record a range of concordant and near-concordant 207Pb/206Pb dates between ∼3560 and 3230 Ma, the youngest group yielding a weighted mean date of 3227±7 Ma. This range of dates is interpreted to be due to a combination of metamorphic recrystallization and high- temperature Pb-loss in originally detrital zircons during regional metamorphism. A minimum age for the timing of deformation is given by the emplacement age of 3229±5 Ma for the late-kinematic trondhjemite. Thus, geochronological data support the notion of a major metamorphic episode that coincided with the proposed short-lived terrane accretion event in the centre of the Barberton greenstone belt.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2005

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Footnotes

Current address: Institut für Mineralogie und Lagerstättenlehre, RWTH Aachen, Wüllnerstraße 2, D-52062 Aachen, Germany

References

Anhaeusser, C.R. and Robb, L.J. (1980) Regional and detailed field and geochemical studies of Archaean trondhjemitic gneisses, migmatites and greenstone xenoliths in the southern part of the Barberton mountain land, South Africa. Precambrian Research, 11, 373397.CrossRefGoogle Scholar
Anhaeusser, C.R., Robb, L.J. and Barton, J.M. Jr., (1983a) Mineralogy, petrology and origin of the Boesmanskop syeno-granite complex, Barberton Mountain Land, South Africa. Special Publications of the Geological Society of South Africa, 9, 169183.Google Scholar
Anhaeusser, C.R., Robb, L.J. and Viljoen, M.J. (1983b) Notes on the provisional geological map of the Barberton greenstone belt and surrounding granitic terrane, eastern Transvaal and Swaziland (1:250,000 colour map). Special Publications of the Geological Society of South Africa, 9, 221223.Google Scholar
Armstrong, R.A., Compston, W., de Wit, M.J. and Williams, I.S. (1990) The stratigraphy of the 3.5-3.2 Ga Barberton greenstone belt revisited; a single zircon ion microprobe study. Earth and Planetary Science Letters, 101, 90106.CrossRefGoogle Scholar
Ashwal, L.D., Tucker, R.D. and Zinner, E.K. (1999) Slow cooling of deep crustal granulites and Pb-loss in zircon. Geochimica et Cosmochimica Acta, 63, 28392851.CrossRefGoogle Scholar
Brandl, G. and de Wit, M.J. (1997) The Kaapvaal Craton, South Africa. Pp. 581607 in: Greenstone Belts (de Wit, M.J. and Ashwal, L.D., editors). Oxford Monographs on Geology and Geophysics, 35, Oxford University Press, Oxford, UK.Google Scholar
Carson, C.J., Ague, J.J., Grove, M., Coath, C.D. and Harrison, T.M. (2002) U-Pb isotopic behaviour of zircon during upper-amphibolite facies fluid infiltration in the Napier Complex, east Antarctica. Earth and Planetary Science Letters, 199, 287310.CrossRefGoogle Scholar
Cherniak, D.J. (1993) Lead diffusion in titanite and preliminary results on the effects of radiation damage on Pb transport. Chemical Geology, 110, 177194.CrossRefGoogle Scholar
Cloete, M. (1991) An overview of metamorphism in the Barberton greenstone belt. Pp. 8598 in: Two Cratons and an Orogen — Excursion Guidebook and Review Articles for a Field Workshop through Selected Archaean Terranes of Swaziland, South Africa and Zimbabwe (Ashwal, L.D., editor). IGCP Project 280, Dept. of Geology, University of the Witwatersrand, Johannesburg, South Africa.Google Scholar
Cloete, M. (1994) Aspects ofvolcanism and metamorphism of the Onverwacht Group lavas in the southwestern portion of the Barberton greenstone belt. Ph.D. thesis (unpublished), University of the Witwatersrand, Johannesburg, 419 pp.Google Scholar
Compston, W., Williams, I.S., Kirschvink, J.L., Zhang, Z. and Ma, G. (1992) Zircon U-Pb ages for the early Cambrian time-scale. Journal of the Geological Society, London, 149, 171184.CrossRefGoogle Scholar
Degeling, H., Eggins, S. and Ellis, D.J. (2001) Zr budgets for metamorphic reactions and the formation of zircon from garnet breakdown. Mineralogical Magazine, 65, 749758.CrossRefGoogle Scholar
De Ronde, C.E.J. and de Wit, M.J. (1994) Tectonic history of the Barberton greenstone belt, South Africa; 490 million years of Archaean crustal evolution. Tectonics, 13, 9831005.CrossRefGoogle Scholar
De Ronde, C.E.J. and Kamo, S.L. (2000) An Archaean arc-arc collisional event: a short-lived (ca 3 Myr) episode, Weltevreden area, Barberton greenstone belt, South Africa. Journal of African Earth Science, 2, 219248.CrossRefGoogle Scholar
Dziggel, A., Stevens, G., Poujol, M., Anhaeusser, C.R. and Armstrong, R.A. (2002) Metamorphism of the granite-greenstone terrane to the south of the Barberton greenstone belt, South Africa: an insight into the tectono-thermal evolution of the ‘lower’ portions of the Onverwacht Group. Precambrian Research, 114, 221247.CrossRefGoogle Scholar
Dziggel, A., Stevens, G., Poujol, M. and Armstrong, R.A. (2005) Contrasting source components of clastic metasedimentary rocks in the lowermost formations of the Barberton greenstone belt. Geological Society of America Special Paper, 405 (in press).Google Scholar
Frost, B.R., Chamberlain, K.R. and Schumacher, J.C. (2000) Sphene (titanite): phase relations and role as geochronometer. Chemical Geology,172, 131 — 148.Google Scholar
Hawkins, D.P. and Bowring, S.A. (1999) U-Pb monazite, xenotime and titanite geochronological constraints in the prograde to post-peak metamorphic thermal history of Paleoproterozoic migmatites from the Grand Canyon, Arizona. Contributions to Mineralogy and Petrology, 134, 150169.CrossRefGoogle Scholar
Irmer, G. (1985) Zum Einfluß der Apparatefunktion auf die Bestimmung von Streuquerschnitten und Lebensdauern aus optischen Phononenspektren. Experimentelle Technik der Physik, 33, 501506.Google Scholar
Kamo, S.L. and Davis, D.W. (1994) Reassessment of Archaean crustal development in the Barberton Mountain Land, South Africa, based on U-Pb dating. Tectonics, 13, 165192.CrossRefGoogle Scholar
Kisters, A.F.M., Stevens, G., Dziggel, A. and Armstrong, R.A. (2003) Extensional detachment faulting at the base of the Barberton greenstone belt: evidence for a 3.2 Ga orogenic collapse. Precambrian Research, 127, 355378.CrossRefGoogle Scholar
Kretz, R. (1983) Symbols for rock-forming minerals. American Mineralogist, 68, 277279.Google Scholar
Leake, B.E., Woolley, A.R., Arps, C.E.S., Birch, W.D., Gilbert, M.C., Grice, J.D., Hawthorne, F.C., Kato, A., Kisch, H.J., Krivovichev, V.G., Linthout, K., Laird, J., Mandarino, J., Maresch, W.V., Nickel, E.H., Rock, N.M.S., Schumacher, J.C., Smith, D.C., Stephenson, N.C.N., Ungaretti, L., Whitaker, E.J.W. and Youzhi, G. (1997) Nomenclature of amphiboles: report of the Subcommittee on Amphiboles of the International Mineralogical Association Commission on New Minerals and Mineral Names. European Journal of Mineralogy, 9, 623651.CrossRefGoogle Scholar
Lee, J.K.W., Williams, I.S. and Ellis, D.J. (1997) Pb, U and Th diffusion in natural zircon. Nature, 390, 159162.CrossRefGoogle Scholar
Lopez Martinez, M., York, D., Hall, CM. and Hanes, J.A. (1984) Oldest reliable 40Ar/39Ar ages for terrestrial rocks: Barberton Mountain komatiites. Nature, 307, 352354.CrossRefGoogle Scholar
Lopez Martinez, M., York, D. and Hanes, J.A. (1992) A 40Ar/39Ar geochronological study of komatiites and komatiitic basalts from the lower Onverwacht volcanics: Barberton Mountain Land, South Africa. Precambrian Research, 57, 91119.CrossRefGoogle Scholar
Lowe, D.R. (1994) Accretionary history of the Archaean Barberton greenstone belt (3.55-3.22 Ga), South Africa. Geology, 22, 10991102.2.3.CO;2>CrossRefGoogle Scholar
Lowe, D.R. (1999) Geologic evolution of the Barberton greenstone belt and vicinity. Geological Society of America Special Paper, 329, 287312.Google Scholar
Ludwig, K.R. (2000a) Isoplot/Ex: a geochronological toolkit for Microsoft Excel®. Berkeley Geochronology Center, Berkeley, California.Google Scholar
Ludwig, K.R. (2000b) SQUID 1.00, A User's Manual. Berkeley Geochronology Center Specical Publications, 2, Berkeley, California, 17 pp.Google Scholar
Meldrum, A., Boatner, L.A., Weber, W.J. and Ewing, R.C. (1998) Radiation damage in zircon and monazite. Geochimica et Cosmochimica Acta, 62, 25092520.CrossRefGoogle Scholar
Mezger, K. and Krogstad, E.J. (1997) Interpretation of discordant U-Pb zircon ages: an evaluation. Journal of Metamorphic Geology, 15, 127140.CrossRefGoogle Scholar
Möller, A., Mezger, K. and Schenk, V. (2000) U-Pb dating of metamorphic minerals: Pan-African metamorphism and prolonged slow cooling of high pressure granulites in Tanzania, East Africa. Precambrian Research, 104, 123146.CrossRefGoogle Scholar
Möller, A., O'Brian, P.J., Kennedy, A. and Kröner, A. (2002) Polyphase zircon in ultrahigh-temperature granulites (Rogaland, SW Norway): constraints for Pb diffusion in zircon. Journal of Metamorphic Geology, 20, 727740.CrossRefGoogle Scholar
Murakami, T., Chakoumakos, B.C., Ewing, R.C., Lumpkin, G.R. and Weber, W.J. (1991) Alpha-decay event damage in zircon. American Mineralogist, 76, 15101532.Google Scholar
Nasdala, L., Wolf, D. and Irmer, G. (1995) The degree of metamictization in zircon: a Raman spectroscopic study. European Journal of Mineralogy, 7, 471478.CrossRefGoogle Scholar
Nasdala, L., Pidgeon, R.T., Wolf, D. and Irmer, G. (1998) Metamictization and U-Pb isotopic discordance in single zircons: a combined Raman micro-probe and SHRIMP ion probe study. Mineralogy and Petrology, 62, 127.CrossRefGoogle Scholar
Nasdala, L. Wenzel, M., Vavra, G., Irmer, G., Wenzel, T. and Kober, B. (2001) Metamictisation of natural zircon: accumulation versus thermal annealing of radioactivity-induced damage. Contributions to Mineralogy and Petrology, 141, 125144.CrossRefGoogle Scholar
Nasdala, L., Lengauer, C.L., Hanchar, J.M., Kronz, A., Wirth, R., Blanc, P., Kennedy, A.K. and Seydoux-Guillaume, A.M. (2002) Annealing radiation damage and the recovery of cathodoluminescence. Chemical Geology, 191, 121140.CrossRefGoogle Scholar
Paces, J.B. and Miller, J.D. Jr (1993) Precise U-Pb ages of Duluth Complex and related mafic intrusions, northeastern Minnesota: geochronological insights to physical, petrogenetic, paleomagnetic and tectono-magmatic processes associated with the 1.1 Ga Midcontinental Rift System. Journal of Geophysical Research, B98, 1399714013.CrossRefGoogle Scholar
Robb, L.J., Armstrong, R.A. and Waters, D.J. (1999) The history of granulite-facies metamorphism and crustal growth from single zircon U-Pb geochronology: Namaqualand, South Africa. Journal of Petrology, 40, 17471770.CrossRefGoogle Scholar
Stacey, J.S. and Kramers, J.D. (1975) Approximation of terrestrial lead isotope evolution by a two stage model. Earth and Planetary Science Letters, 26, 207221.CrossRefGoogle Scholar
Stevens, G., Droop, G.T.R., Armstrong, R.A. and Anhaeusser, C.R. (2002) Amphibolite facies metamorphism in the Schapenburg schist belt: A record of the mid-crustal response to ∼3.23 Ga terrane accretion in the Barberton greenstone belt. South African Journal of Geology, 105, 271284.CrossRefGoogle Scholar
Vavra, G., Schmid, R. and Gebauer, D. (1999) Internal morphology, habit and U—Th-Pb microanalysis of amphibole to granulite facies zircon. Contributions to Mineralogy and Petrology 134, 380404.CrossRefGoogle Scholar
Westraat, J.D., Kisters, A.F.M., Poujol, M. and Stevens, G. (2005). Transcurrent shearing, granite sheeting and the incremental construction of the tabular 3.1 Ga Mpuluzi batholith, Barberton granite-greenstone terrane, South Africa. Journal of the Geological Society, London, 162, 373388.Google Scholar
Williams, I.S. (1998) U-Th-Pb geochronology by ion microprobe. Pp. 135 in: Applications of Microanalytical Techniques to Understanding Mineralising Processes (McKibbon, M.A. Shanks, W.C. III and Ridley, W.I., editors). Reviews in Economic Geology, 7.Google Scholar
Williams, I.S. and Claesson, S. (1987) Isotopic evidence for the Precambrian provenance and Caledonian metamorphism of high grade paragneisses from the Seve Nappes, Scandinavian Caledonides. II. Ion microprobe zircon U-Th-Pb. Contributions to Mineralogy and Petrology, 97, 205–21.CrossRefGoogle Scholar
Xie, X., Byerly, G.R. and Ferrell, R.E. Jr, (1997) IIb trioctahedral chlorite from the Barberton greenstone belt; crystal structure and rock composition constraints with implications to geothermometry. Contributions to Mineralogy and Petrology, 126, 275291.CrossRefGoogle Scholar
Zeck, H.P. and Whitehouse, M.J. (2002) Repeated age resetting in zircons from Hercynian-Alpine poly-metamorphic schists (Betic-Rif tectonic belt, S. Spain) — a U-Th-Pb ion microprobe study. Chemical Geology, 182, 275292.CrossRefGoogle Scholar