| Abstract |
Rungwe volcanic province is marked by Plio/Pleistocene to recent eruptive and tectonic events. It is located at southern triple junction of the East Africa Rift System (EARS) in Mbeya region, southern Tanzania. The province is dominated by three major volcanic centres, namely; The Main Rungwe volcano, Kiejo volcano and Ngozi volcano. This paper describes structural influences on volcanism and hydrothermal systems in the area based on field observations. Structurally Rungwe Volcanic Province is characterised by presence of Rungwe caldera, Ngozi caldera, caldera ring structures, the dominant NW trending structures including the Mbaka fault, Mbeya front escarpment, Ifisi fault, Mbalizi fault and Lupa fault system, which follow the regional NW trending structural corridor largely influenced by Neogene Nyasa rifting and Rukwa rifting. It is observed that underlying structures may have not only influenced the locations of these three volcanic centres but also the hydrothermal system associated with them. Rungwe being the main volcanic system and underlying basement structure may have enabled magma conduits to the north and south resulting in Ngozi and Kiejo eruptions. |