Quick Search:    advanced search

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

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted 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 (3) Citing Articles via Google Scholar Google Scholar Articles by Johnston, S.T. Articles by Mitchell, A. A. Search for Related Content GeoRef GeoRef Citation

The Tugela Terrane, Natal belt: Kibaran magmatism and tectonism along the southeast margin of the Kaapvaal Craton

School of Earth and Ocean Science, University of Victoria, PO Box 3055, STN CSC Victoria, British Columbia, Canada, V8W 3P6, e-mail: stj{at}uvic.ca

S. McCourt, A. Bisnath and A. A. Mitchell

Department of Geology, University of Durban-Westville, Private Bag X54001, Durban, 4000, South Africa

This paper is a preliminary report on the geology of the Mandleni tectonostratigraphic package (MTP) part of the Tugela terrane, the northernmost element of the Natal belt in southeastern Africa. The Dondwana gneiss unit, a metamorphosed bimodal magmatic sequence comprising feldspathic gneiss, with lesser amounts of amphibolite, underlies much of the MTP. All primary structures in these rocks have been obliterated during post-depositional metamorphism and deformation. Fabrics attributable to the oldest recognised tectonic event (D₁) have largely been overprinted during subsequent deformation. D₂ was characterised by syn-kinematic high-pressure (P>9 kbar) granulite facies metamorphism. The dominant S₂ planar fabric is a penetrative gneissic foliation that parallels lithological contacts. It is defined by colour and compositional banding, and by parallelism of coarsely crystalline mineral grains. D₃ tectonism produced asymmetric north-verging folds, faults and shear zones, which accommodated overthrusting of the MTP onto the Kaapvaal craton. Plagioclase ± biotite mantles on garnet developed at this time and are attributable to uplift of the MTP from the mid- to deep-crustal levels established during D₂. Ultramafic rocks (the Evuleka ultramafics) tectonically interleaved with the Dondwana gneiss unit during D₃, consist of talc schist, and massive serpentinite with disseminated chromite and magnetite. These ultramafic rocks are interpreted as altered and sheared mantle or cumulate from the lower portion of an ophiolite sequence. Granitoid magmatism associated with D₃ is related to subduction beneath the MTP. This subduction led to basin-closure and emplacement of the MTP onto the Kaapvaal craton. The final tectonic event (D₄) produced broad open south-plunging folds and sinistral shear zones.

This article has been cited by other articles:

				I. J. Basson, I.J. Basson, and M.K. Watkeys Tectonic implications from the geochemistry of Mfongosi Group metasediments, Natal Metamorphic Province, South Africa South African Journal of Geology, December 1, 2003; 106(4): 265 - 280. [Abstract] [Full Text] [PDF]