TROPICAL HEIGHTS AFRICA LIMITED

Tropical Heights Africa operates within Uganda in East Africa. The geology of Uganda creates high mineralisation.Indeed  Uganda lies within the African plate, which is a continental crust that contains Archaean cratons that date at least 2700 Ma. The country’s geology endowed with a wide variety of minerals has been grouped into the following geological litho-stragraphic domains.

Basement Complex- is of predominantly granitic metamorphic rocks of Archaean shield in central and northern areas of the country. Little mapping has been undertaken to differentiate the rock units. This domain has a variety of minerals which include asbestos, graphite, kyanite, garnet, talc, felspar, kaolin, clays and stone for aggregate.

Nyanzian System- this is situated in the southeast of the country and is comprised principally of mafic volcanic rocks and sediments. It forms gold-bearing greenstone belt which is part of the famous Lake Victoria gold field of northern Tanzania and western Kenya. Gold mineralisation is confined to quartz veins within the basic metavolcanics, within banded-iron formations (BIF) or in the rocks adjacent to the BIF units. Currently, Tira Gold Mine is in production.

Buganda-Toro System (2000-1800 Ma)- is composed of argillaceous rocks together with quartzites and stretches from the southwest of the country through Rwenzori Mountains swinging eastward to north of Lake Victoria. In some areas in central and southern parts within this belt, the rocks are metamorphosed to a higher degree reaching the almandine-amphibolite facies. The system is a host to gold, base metals such as copper, cobalt, nickel, columbite-tantalite and tungsten. Copper was mined at Kilembe from 1957 to 1978 and contributed 95% by value of all the country’s mineral exports. At closure of the mine in 1979, reserves were approximately 6 million tonnes of which 4.2 million tonnes with copper and cobalt content of 1.77% and 0.185 respectively were in proven category.

Karagwe-Ankolean (1400-1300 Ma) System-extends from southwest of the country for over 2000 kilometres to Katanga in the Democratic Republic of Congo. The rocks are similar to those of the Buganda-Toro System but are usually less metamorphosed. Intrusive porphyritic granites within the cores of anticlines are a common feature. The system is a major host of gold, tin, tungsten, beryl, lithium, columbite, tantalite, bismuth and iron ore. Most gold workings in the belt have been largely by artisans.

Karasuk Group (1300 Ma)- this group comprises of rocks from Archaean to Upper Proterozoic which were overprinted by events of the Mozambique orogenesis. The group is found in the northeast of the country in Karamoja region and consists of acid and basic flaggy gneisses, quartzites and marbles. A unique feature of this group is the occurrence of chromite-rich “pods” thought to represent an ophiolite suite of rocks. The group also hosts gold, nickel, platinum, copper and gemstones.

Carbonatite ring Complexes- these are of as early as Cretaceous and represent eroded remnants of volcanics of similar geological suite and occur in several localities in the eastern part of the country. They host limestone, pyrochlore, vermiculite, titanium, vanadium, zircon, baddeleyite, uranium, thorium and traces of copper. Vermiculite at Namekhara has been developed into an active mine at a production rate of tonnes per month.

Bunyoro-Kyoga Group- these Upper Proterozoic rocks consist of mudstones and arkoses with a basal tillite in a belt parallel to the eastern side of the Lake Albert Rift and along the northern shores of Lake Kyoga.

Mesozoic and Cainozoic rocks- these comprise of volcanics and sediments. The main areas of volcanicity are in the eastern and southwestern Uganda. The eastern volcanics are older and range from Cretaceous to Miocene and comprise generally soda-rich agglomerates, lavas and tuffs extruded by central volcanoes of Moroto, Kadam and Elgon Mountains. In western Uganda, volcanism was confined entirely to the later Pleistocene and the volcanics are potash-rich in contrast to those of the east. They form prominent cones of Mt. Mufumbira and are also represented by tuffs ejected from explosion craters in areas between Lake George and Fort Portal. Although no active volcanoes remain in Uganda, some continue to erupt sporadically in Democratic republic of Congo within 40 km of the Uganda border.

With the exception of alluvial deposits in swamps and valleys, Cainozoic sediments occur only in restricted areas. In eastern Uganda, the Miocene Bugisu series underlies Mt. Elgon while in western Uganda, they occur within the confines of the Western Rift Valley where they attain at least 4000m thickness. The Rift Valley sediments host limestone, gypsum, diatomite, clay, gravel and evaporates such as salts. Most exploitation of these resources is by artisanal means with the exception of a handful of mechanised plants which are currently manufacturing cement, baked bricks and roofing tiles.

Major structures- owing to poor exposures, faults are in general difficult to trace in the older rocks. However, two significant zones of faulting are evident i.e., the Aswa fault which is a zone of mylonites striking southeast from northwest in northern Uganda and can be traced for over 300 kilometres and the Western Rift Valley which is part of African Rift that contains lakes Malawi, Tanganyika, Kivu, Edward, George and Albert.