Deep-crustal granulites with migmatitic and mylonitic fabrics from the Zambezi Belt, northeastern Zimbabwe |
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| Authors: | J N CARNEY P J TRELOAR C M BARTON M J CROW J A EVANS S SIMANGO |
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| Institution: | British Geological Survey, Keyworth, Nottingham NG12 5GG, UK;Department of Geology, Imperial College, London SW7 2BP, UK;British Geological Survey, St Just, 30 Pennsylvania Road, Exeter EX4 6BX, UK;NERC Isotope Geosciences Laboratory, Keyworth, Nottingham NG12 5GG, UK;Geological Survey Department, PO Box 8039, Causeway, Harare, Zimbabwe |
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| Abstract: | Abstract High- P granulites contained in two allochthonous tectonic units were thrust southwards onto the northern margin of the Zimbabwe craton during the Pan-African Zambezi orogeny. In the lower sheet, the Masoso Metamorphic Suite contains mafic garnet granulite assemblages formed during a high- P-T metamorphic event, although the suite as a whole is predominantly granitic. The garnet granulites occur as relicts within narrow mafic layers characterized by migmatitic and mylonitic fabrics. The annealed mylonites represent surfaces of deep-crustal tectonic imbrication that formed immediately before the Pan-African orogeny. Gabbros which intruded the granulites after the main phase of migmatization have formed corona textures that document a low- P-T metamorphic event at mid-crustal levels. The style of deformation then changed and the Masoso Suite with its mylonitic layers was folded and thrusted southwards onto the Archaean Zimbabwe craton. |
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| Keywords: | granulite migmatite mylonite Zambezi Belt Zimbabwe |
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