Mozambique Orogenic Belt Research Articles

Photogeology and structure of the Mozambique orogenic front near Kolo, north-east Tanzania

A regional investigation into part of the Mozambique Orogenic Belt in north-east Tanzania is based on photogeological interpretation supported by ground work at selected localities. A 15-mile traverse was made, near Kolo, from the granitoid Tanganyika Shield towards the adjacent orogen in order to establish the structure and tectonic relationships across the front. Three tectonic domains and two subsequent deformations were recognized. One of the domains (Kondoan) corresponds to the tectonically reworked margin of the Shield, which itself consists of a batholithic granite and a marginal series of gneisses (Parangan). Analysis of the structural data obtained on the ground shows that the tectonic domains which were postulated, in part photogeologically, on grounds of distinctive structural styles, display some degree of structural homogeneity. The western domains, which constitute the foreland, are deformed by shearing. The onset of tectonic reworking in the Kondoan domain converts the pre-existing rocks into flaggy gneisses dipping to the east. The axial planes of all the imposed folds dip eastwards towards the orogenic belt and the axes of deformation plunge predominantly towards the east-southeast and south-east, i.e. transverse to the general north-south trend of the orogenic belt. Comparison with other regions suggests that at similar tectonic levels folding, with stretching in the axial direction transverse to the orogenic front, is a common feature in the development of mountain chains.

Photogeological Investigation of the Mozambique Front in Tanzania

THE boundary between the Tanganyika Shield arid the Mozambique Orogenic Belt in north-central Tanzania is being investigated by means of an initial photogeological study of an area of about 70,000 square miles, making use of the extensive reconnaissance mapping by the Tanzania Geological Survey.

Zones of Progressive Regional Metamorphism Across the Western Margin of the Mozambique Belt in Rhodesia and Mozambique

AbstractInvestigations of the sedimentary rocks of the Umkondo System have enabled six zones of eastwardly increasing metamorphic grade to be delineated on the basis of index mineral assemblages in pelite horizons.Chlorite, garnet (almandine), staurolite, kyanite, and sillimanite isograds have been recognized over a distance of 500 km. along the eastern border of Southern Rhodesia and are plotted on a map. More detailed reconnaissance work has been confined to the Barué highlands north-east of Inyanga. In addition, a “zone of intermediate isotopic age measurements” is proposed to the west of the lowermost chlorite zone. The isograds lie parallel to the structural edge of the north-south trending Mozambique orogenic belt and can be joined with those of similar metamorphic rocks in the east-west trending Zambesi orogenic belt, suggesting contemporaneity of the c. 500 m.y. regional tectono-thermal event in these two belts.

Monte Senga-Senga, a domal structure in Central Moçambique

A circular structure, first recognized on aerial photographs, occurs at the northern end of the Gairezi-Barue highlands in the province of Manica e Sofala. This feature, known as Mte. Senga-Senga, was visited briefly and was found to consist of a nearly perfectly circular core of granitic gneiss of Mozambique Orogenic Belt type overlain by outward-dipping quartzites and pelites of the late-Precambrian Umkondo System. Although the structure of this feature is problematical, it might be a mantled gneiss dome. Other domes occur elsewhere in the area, but Senga-Senga which is completely encircled by the mantle rocks, and may represent a high structural level, is particularly worthy of a more detailed study.