The Kapalagulu basic complex, Tanganika Territory

Abstract

The Kapalagulu Complex is situated near the eastern coast of Lake Tanganyika, and some 70 miles south of Kigoma. The Complex is sill-like to lopolithicin shape, intrudes the Basement System (Archaean) , and is overlain by sediments of the Bukoban System. Locally, both the Complex and the country-rocks have been tilted to a sub-vertical position., and consequently they are exposed in stratigraphical cross-section along the land surface. As a result of magmatic segregation during crystallization of the Intrusion, three 'conformable' z:ones are formed: (1) A Basal Zone of bronzite picrite; ( 2) An Intermediate Zone of banded olivine hyperite; and (3) A Main Zone, in which the most cormmon rock-type is hyperite,. The Main Zone contains an interstratified Anorthosite Band. Within the Basal Zone is a horizon along which there is a high concentration of sulphides. The sulphides of this Ore Zone are mostly pyrrhotite, and presumably they concentrated by settling on –––becoming immiscible in the magma.