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Deep‐crustal granulites with migmatitic and mylonitic fabrics from the Zambezi Belt, northeastern Zimbabwe
Author(s) -
CARNEY J. N.,
TRELOAR P. J.,
BARTON C. M.,
CROW M. J.,
EVANS J. A.,
SIMANGO S.
Publication year - 1991
Publication title -
journal of metamorphic geology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.639
H-Index - 114
eISSN - 1525-1314
pISSN - 0263-4929
DOI - 10.1111/j.1525-1314.1991.tb00540.x
Subject(s) - granulite , geology , mylonite , geochemistry , orogeny , craton , metamorphic rock , mafic , shear zone , metamorphism , petrology , archean , tectonics , seismology , geomorphology , facies , structural basin
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.