SEAMIC Newsletter Vol. 10

Major Structures
There are two major structural patterns in Uganda namely:
♦ Aswa fault Zone: This is a zone of mylonites trending northwest-southeast from Nimule
in Sudan following the course of the Nile to near Mt. Elgon in the southeast for over 300
kilometres along the course of River Aswa.
♦
The Western Rift Valley: This is part of East African Rift system and runs the length of
Uganda from north-east to south-west. It constitutes the Lake Edward, George, Albert
and the Rwenzori Mountains horst block.
MINERAL POTENTIAL OF UGANDA
Ores of various metallic minerals and industrial minerals have been discovered in Uganda,
others developed into mines while a number of them are being evaluated by the private sector
for their economic potential. Numerous artisanal mining and small scale exploitation of mineral
resources is on-going.
Metallic Minerals
Copper ores
♦ Kilembe: Chalcopyrite, pyrite and pyrrhotite form the primary copper ores. The reserves
were approximately 6 million tonnes of which 4.2 million tonnes with a copper content of
1.77% were in proven category. The ore is associated with cobalt (currently being extracted
through bio-leach method), nickel and gold as well as kaolin.
♦ Karamoja region: Copper mineralization in Karamoja is associated with zinc, gold and
silver.
Iron ores: Iron occur at Muko (30-50 million tonnes at up to 98% Fe 2 O 3 ), Butare (1.1 million
tonnes), Kashenyi (1.2 million tonnes), Kyanyamuzinda (2.4 million tones) and Kamena in
southwestern Uganda. In eastern Uganda iron ores are found at Sukulu (45 million tones at
62% Fe) and Bukusu (23 million tonnes at 62% Fe) in Tororo and Mbale districts respectively.
Tin ores (Cassiterite): Tin province of Uganda is found in the Karagwe-Ankolean System.
Cassiterite is confined to shales and sandstones in elluvial, detrital, pegmatitic and
hydrothermal vein deposits.
Tungsten: Wolframite is found in two regions: the southwestern Uganda and the Singo area in
Mubende district. They can be classified as mesothermal deposits of low-grade and
hypothermal high grade deposits. Major wolfram producing mines in Uganda belonging to the
former type are Nyamuliro (0.7 million tonnes at 0.15% wolfram), Ruhizha (20 million tones
at up to 4% wolfram) of inferred resources still in place and Kirwa (2.7 million tonnes of
indicated and inferred resource at a grade of 0.13% wolfram) still expected at the mine.
Gold
♦ Busia-Bugiri goldfield: Gold was discovered near Busia in 1932 by the Geological Survey
of Uganda. Vein and alluvial prospects have been mined sporadically where most of 1.0 to
1.5 tonnes of gold produced from 1937 to 1952 came from the Tira and Amonikakinei
mines.
♦ Buhweju Goldfield: The bulk of won gold in Uganda was from small but rich alluvials on
and around the Buhweju Plateau, which is a large Middle Proterozoic basin (1,600-
900Ma) composed of phyllites, shales, schists and quartzite rocks of the Karagwe-
Ankolean System.
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