Introduction.

As with tin, tungsten has been produced only in the Karagwe Tinfield. Scheelite and ferberite have been noted in veins in the Ibindi Njiapanda area of the Mpanda Mineral Field (Fig 34), but no production ensured. Minor amounts of wolframite and scheelite have been noted in several auriferous veins in the Lake Victoria greenstone belt. Cumulative production in Karagwe since 1935 has been 250-30tonnes of wolframite.

Geology.

The four productive areas (Chamunyana, Karugu, Kazumeru and Kibanda) in Karagwe Tinfield share several features in common and are probably similar in geology. In all four areas, wolframite is associated with quartz vein. At Karugu, Chamunyana and Kazumeru (Fig 44) the veins cut phyllite adjacent to a granite body. Other minerals noted are arsenopyrite, hematite, muscovite and tourmaline. Veins are up to 1.5 m wide and averaged 1.0-1.5% wolframite. Kibanda is described as a zone of greisen alteration above a buried granite cupola. The Karagwe tungsten mineralisation could be classified within the "W vein model", no 15a of Cox and Singer (1986). Metal occurrences in this part of Tanzania are described in UNDP REPORTS (1980 and 1985).

Opportunities.

Similar comments made for tin apply to tungsten mining in the Karagwe area. However, the relatively more sensitive mechanical separation of wolframite and ferberite from gangue minerals would be an additional consideration.