Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

Geological Magazine

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (16) Citing Articles via Google Scholar Google Scholar Articles by MAPEO, R. B. M. Articles by KAMPUNZU, A. B. Search for Related Content GeoRef GeoRef Citation

SHRIMP U–Pb zircon geochronology of gneisses from the Gweta borehole, northeast Botswana: implications for the Palaeoproterozoic Magondi Belt in southern Africa

R. B. M. MAPEO^*,, R. A. ARMSTRONG and A. B. KAMPUNZU^*

^* Department of Geology, University of Botswana, Private Bag 0022, Gaborone, Botswana
Research School of Earth Sciences, The Australian National University, Canberra, ACT 0200 Australia

Author for correspondence: e-mail: mapeorbm{at}mopipi.ub.bw

This paper presents new U–Pb zircon analyses from garnet–sillimanite paragneisses from the Gweta borehole in northeast Botswana. Concordant to near-concordant analyses of zircon from these rocks reveal a billion year history from 3015 ± 21 Ma for the oldest detrital grain measured, to the age of high-grade metamorphism, 2027 ± 8 Ma. The maximum age of sedimentation in the Magondi belt is constrained by the age of the youngest concordant detrital zircon at 2125 ± 6 Ma. This contrasts with the age of sedimentation in the Central Zone of the Limpopo belt which is Archaean. The comparison of our results with U–Pb zircon data from the Magondi belt in Zimbabwe suggests that the granulite-facies metamorphism in this belt extended between c. 2027–1960 Ma. Granulite-facies rocks with U–Pb zircon ages in this interval are also known in the Ubendian belt and lend support to the correlation of these two segments of Palaeoproterozoic belts in southern and central–eastern Africa. The granulite facies metamorphism in the Magondi belt is coeval with the high-grade metamorphism and granitoids documented further south in the Central Zone of the Limpopo Belt.

This article has been cited by other articles:

				B. M. Eglington, S. M. Reddy, and D. A. D. Evans The IGCP 509 database system: design and application of a tool to capture and illustrate litho- and chrono-stratigraphic information for Palaeoproterozoic tectonic domains, large igneous provinces and ore deposits; with examples from southern Africa Geological Society, London, Special Publications, January 1, 2009; 323(1): 27 - 47. [Abstract] [Full Text] [PDF]

				P. Alexandre, M. A.G. Andreoli, A. Jamison, and R. L. Gibson 40Ar/39Ar age constraints on low-grade metamorphism and cleavage development in the Transvaal Supergroup (central Kaapvaal craton, South Africa): implications for the tectonic setting of the Bushveld Igneous Complex South African Journal of Geology, September 1, 2006; 109(3): 393 - 410. [Abstract] [Full Text] [PDF]

				H.C. Dorland, N.J. Beukes, J. Gutzmer, D.A.D. Evans, and R.A. Armstrong Precise SHRIMP U-Pb zircon age constraints on the lower Waterberg and Soutpansberg Groups, South Africa South African Journal of Geology, June 1, 2006; 109(1-2): 139 - 156. [Abstract] [Full Text] [PDF]

				P. G. Silver, M. J. Fouch, S. S. Gao, M. Schmitz, and Kaapvaal Seismic Group Seismic anisotropy, mantle fabric, and the magmatic evolution of Precambrian southern Africa South African Journal of Geology, June 1, 2004; 107(1-2): 45 - 58. [Abstract] [Full Text] [PDF]

				S. McCourt, A.B. Kampunzu, Z. Bagai, and R.A. Armstrong The crustal architecture of Archaean terranes in Northeastern Botswana South African Journal of Geology, June 1, 2004; 107(1-2): 147 - 158. [Abstract] [Full Text] [PDF]

				R.B.M. Mapeo, A. B. Kampunzu, L.V. Ramokate, F. Corfu, and R. M. Key Bushveld-age magmatism in southeastern Botswana: evidence from U-Pb zircon and titanite geochronology of the Moshaneng Complex South African Journal of Geology, June 1, 2004; 107(1-2): 219 - 232. [Abstract] [Full Text] [PDF]

				I. S. Buick, I.S. Buick, I.S. Williams, R.L. Gibson, I. Cartwright, and J.A. Miller Carbon and U-Pb evidence for a Palaeoproterozoic crustal component in the Central Zone of the Limpopo Belt, South Africa Journal of the Geological Society, July 1, 2003; 160(4): 601 - 612. [Abstract] [Full Text] [PDF]

				R. E. Hanson Proterozoic geochronology and tectonic evolution of southern Africa Geological Society, London, Special Publications, January 1, 2003; 206(1): 427 - 463. [Abstract] [PDF]