Namibia

Intrusive Deposits. Deposits included in the intmsive deposit type are those associated with intmsive or anatectic rocks of different chemical composition, eg, alaskite, granite, monzonite, peralkaline syenite, carbonatite, and pegmatite. Examples include the uranium occurrences in the porphyry copper deposits such as Bingham Canyon and Twin Butte in the United States, the Rossing Deposit in Namibia, and Ilimaussaq deposit in Greenland, Palabora in South Africa, and the deposits in the Bancroft area, Canada (15). 

Sur cia.1 Deposits. Uraniferous surficial deposits maybe broadly defined as uraniferous sediments, usually of Tertiary to recent age which have not been subjected to deep burial and may or may not have been calcified to some degree. The uranium deposits associated with calcrete, which occur in Australia, Namibia, and Somaha in semiarid areas where water movement is chiefly subterranean, are included in this type. Additional environments for uranium deposition include peat and bog, karst caverns, as well as pedogenic and stmctural fills (15). 

Cumulative production in countries outside the former USSR, Eastern Europe, and China since the late 1930s has totaled about 1 x 10 t U. A majority of this production came from the United States, Canada, Germany, Namibia, Niger, and South Africa. In addition, some 218,500 t U, 102,245 t U, 16,700 t U, and 16,850 t U have been produced, respectively, in the former GDR, former C2echoSlovakia, Hungary, and Romania. It is estimated that about 72,000 t U have been produced in Ka2akhstan. Reflable cumulative production data for the rest of the CIS, other Eastern European countries, and China, however, are not available (26). 

Canada, Namibia, Niger, South Africa, and the United States (see Table 3). 

Deposits of niobium-tantalum ores are found in Australia, Brazil, Canada, China, Malaysia, Namibia, Nigeria, Russia, Rwanda, Spain, Thailand, Zaire, and Zimbabwe. A more detailed analysis of worldwide tantalum mineral raw material supply can be found in Linden s comprehensive overview [22,23]. 

Rotgieter, M., Davidowitz, B., Blom, B. (2005). Chemical concepts inventory of first year students at two tertiary institutions in South Africa. In the conference proceedings of the 13th Annual Conference Southern African Association of Research in Mathematics, Science and Technology Education. Namibia, pp. 664-675. 

Heaton, T.H.E. 1987 The N/ N ratio of plants in South Africa and Namibia relationship to climate and coastal/saline environments. Oecologia 74 236-246. 

Burger J, Gochfeld M. 2001. Metal levels in feathers of cormorants, flamingos and gulls from the coast of Namibia in southern Africa. Environ Monit Assess 69 195-203. 

Palabora, Namibia Apatite, copper, baddeleyite, vermiculite, uranothorite, magnetite... 

Superficial Deposits associated with calcrete occurring in Australia, Namibia, and Somalia. 

Steyn, C. 2001. The role of Mossgas in Southern Africa. Paper presented at the 2nd Sub-Saharan Africa Catalysis Symposium, Swakopmund, Namibia. 

In contrast to the other large cats, the urine of the cheetah, A. jubatus, is practically odorless to the human nose. An analysis of the organic material from cheetah urine showed that diglycerides, triglycerides, and free sterols are possibly present in the urine and that it contains some of the C2-C8 fatty acids [95], while aldehydes and ketones that are prominent in tiger and leopard urine [96] are absent from cheetah urine. A recent study [97] of the chemical composition of the urine of cheetah in their natural habitat and in captivity has shown that volatile hydrocarbons, aldehydes, saturated and unsaturated cyclic and acyclic ketones, carboxylic acids and short-chain ethers are compound classes represented in minute quantities by more than one member in the urine of this animal. Traces of 2-acetylfuran, acetaldehyde diethyl acetal, ethyl acetate, dimethyl sulfone, formanilide, and larger quantities of urea and elemental sulfur were also present in the urine of this animal. Sulfur was found in all the urine samples collected from male cheetah in captivity in South Africa and from wild cheetah in Namibia. Only one organosulfur compound, dimethyl disulfide, is present in the urine at such a low concentration that it is not detectable by humans [97]. 

Geochemical controls on uranium precipitation in calcrete palaeochannel deposits of Namibia... 

Keywords uranium, hydrogeochemistry, geochemicai modeiiing, Namibia... 

The discovery of the calcrete hosted surfical uranium deposits of Namibia demonstrated the presence of widespread uranium in calcrete filled palaeochannels (Hambleton-Jones 1984) and similar mineral deposits have been observed elsewhere in Southern Africa, USA and Australia (Carlisle 1978 Hambleton-Jones 1978 Mann Deutscher 1978). The host rocks are typically lenticular bodies of alluvium, soil or detritus material cemented by calcite, gypsum, palygorskite, and other mineral phases. Uranium mineralogy is dominated by the mineral Carnotite [K2(U02)2(V04)2.3(H20)] as the main mineral in these channels. However other phases such as andersonite (Na2K3U03(C03)3(H20)6), liebigite (Ca2U02(C03)3(H20)io ... 

Fig. 1. Distribution of calcrete-hosted carnotite deposits in central Namibia (from Hambleton-Jones 1984).

Data has been obtained from published sources and listed data held in the library of the Geological Survey of Namibia. This data has been used to assess the geochemical environment in the vicinity of channel fill and pedogenic uraniumbearing calcrete deposits. The data has been analysed by various methods and laboratories so direct comparison of the data has to be treated with caution. A summary table of the geochemistry of waters from each of the deposits is given in Table 1. 

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