ABSTRACT
The Belingwe Greenstone Belt and surrounding terrain record a complex and diverse deformational and metamorphic history in the period from ca. 3600–2000 Ma ago. Several distinct structural units can be identified. The ancient gneissic basement to the east of the greenstone belt, the Shabani Gneiss Complex, was complexly deformed and then intruded by granodioritic bodies ca. 3500 Ma ago. About 600 Ma later, 2800–2900 Ma ago, the Chingezi Gneiss Complex formed to the west of the belt, immediately followed by intrusion of the Chingezi Tonalite to the west and the Mashaba Tonalite to the east A complex series of deformational and metamorphic events can be recognised in the Shabani Gneiss Complex, but the intense gneiss-forming deformation which occurred in the Chingezi terrain cannot be definitely recognised in the Shabani Complex.
The lower of the two stratigraphic sequences in the Belingwe Belt, the Mtshingwe Group, may have been laid down on an older basement of the Chingezi terrain in the west and Shabani Gneiss in the east. Evidence is strong but not definite that this basal contact is an unconformity. The Mtshingwe Group was folded about a north-east striking axial plane and eroded prior to the unconformable deposition of the 2700 Ma Ngezi Group on a varied terrain of Mtshingwe Group, gneiss and tonalite. This latter unconformity is unequivocally demonstrated by good exposure. Both greenstone sequences were folded and have undergone metamorphism of varying grade, in places up to amphibolite facies but elsewhere in the zeolite facies. Intrusion of younger adamellite and dykes, including the Great Dyke, took place on the margins of the belt.
