SEAMIC Newsletter Vol. 10

Musoma-Mara greenstone belt: The Buhemba Mine produced 12.4 tons of gold and ranked
second after Geita in 1960s. Rocks of Nyanzian Supergroup host the gold mineralisation and
comprise a sequence of basic and felsic volcanics and tuffs with BIF. The Kiabakari, another old
mine, is tabular, siliceous, with steeply dipping ore bodies in sericitic schist, overlain by laterite.
It has been mined to a depth of 450m. The main ore body has a grade of 6.7g/t and is under
exploration. The mine was once the third largest gold producer in Tanzania.
The Afrika Mashariki Mine (Nyabirama and Nyabigena) in North Mara, is a mine under
production with an ore resource of 4.1 M oz gold. The deposit, hosted in andesites and
andesitic tuffs occurs along shear zones. Other deposits include Ikungu, Mrangi, Simba Sirori,
Nyanisero, Nyasirori and Golden Glory.
Nzega greenstone belt: Greenstones of the Nyanzian Supergroup comprise felsic volcanics,
BIF, and subordinate mafic volcanics and sedimentary rocks. Mineralisation is hosted by BIF
or felsic tuffs.
Golden Pride gold deposit: This mine has a resource of over 2.8 M oz at a grade of 2.6 g/t.
Mineralisation is hosted within an east-west striking, steeply dipping, brittle-ductile shear zone
within a sequency of volcaniclastic and siliclastic rocks of Archean age. Lithologies dip steeply
to the north and south. The shear zone mineralization extends over 14 km. Other mines
include: Canuck mine and Matinje mine.
Iramba-Sekenke greenstone belt: Greenstone-belt gold prospects occur over a broad area
concentrated around the Iramba Plateau. The Sekenke Gold Mine was discovered in 1907 and
worked at an average grade of 15.4 g/t gold and 2.5 g/t silver. Several parallel quartz veins
contain gold values close to the contact between greenstones and diorite. Other old mines in
the belt include Kirondatal, Union Gold Mine, Kinyalele, and Kisamamba.
Lupa gold field: The Lupa Gold Field is underlain by a block of deformed and highly
metamorphosed schists and gneisses with intermixed BIF, volcanics and granitic intrusions.
The belt differs from the Lake Victoria goldfield in being hosted by metamorphic rocks of
predominantly Proterozoic age rather than Archean. Gold is associated with quartz reefs
emplaced in shear zones. Alluvial and eluvial gold deposits are not uncommon. The known gold
deposits with past mining record in the area are: New Saza, Gap, Nkutano, Ruth, Maperi,
Razorback, Ntumbi reef, Andura, Chisu, Kasanga bridge and Kizumbe. Placer gold used to be
mined at Chapa, Zira and Matundas. Currently, few exploration companies are in the area
trying to locate mineable gold deposits. Small-scale gold miners are producing limited amount
of gold.
Mpanda gold field: This belt is underlain mainly by rocks of Paleoproterozoic age though some
Archean dates have been reported. The known deposits are: The Mukwamba old base metal
mine (essentially a 0.1-1% copper, 1-3% lead, 1.5 g/t gold and 50-200g/t silver deposit).
Mineralisation is confined to a shear zone in chlorite-sericite schist. In general the veins consist
of banded quartz with variable amounts of siderite, calcite, barite, sericite, hematite, pyrite,
galena, chalcopyrite and gold. Other deposits in the area include, Magamba Reef, D-Reef,
Sikitiko Kapapa and Katuma.
Copper, cobalt and associated minerals
Base-metal occurrences have been found in Archean and Proterozoic rocks of Tanzania. A
world class Kapalagulu platinum-copper-nickel prospect is now under extensive exploration.
The Kabanga nickel-cobalt-copper is another world class deposit on advanced stage of
exploration.
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