1. Classification of uranium deposits:
A listing of the recognized types of uranium mineralization shows nineteen determinable types out of which only six can be classified as of economic significance at present: Oligomictic quartz pebble conglomerates, sandstone types, calcretes, intra-intrusive types, hydrothermal veins, veinlike types. The different types can be genetically related to prevalent geological environments:
a. the primary uranium occurrences formed by endogenic processes (Aliyow Geelle in Bur Complex; and in Northern Crystalline Basement).
b. the secondary derived from the primary by subsequent exogenic processes (produced by processes of tropical chemical weathering such as in calcrete (the Galmudug type).
c. the tertiary occurrences are assumed to be formed by endogenic metamorphic processes.,
However, little is known about the behaviour of the uranium during the metamorphosis and thereby the metallogenesis of this tertiary uranium generation is still vague. A metallotectonic-geochronologic correlation of the uranium deposits shows that a distinct affinity of the uranium exists to certain geologic epochs: to the Upper Archean — Lower Proterozoic, to the Hercynian and in a less established stage: to the Upper Proterozoic.
The uranium deposits in Galgaduud and South Mudug regions of Central Somalia are surficial deposits produced by tropical chemical weathering processes. Surficial uranium deposits are broadly defined as young (Tertiary to Recent) near-surface uranium concentrations in sediments or soils. These deposits usually have secondary cementing minerals including calcite, gypsum, dolomite, ferric oxide, and halite. Uranium deposits in calcrete are the largest of the surficial deposits. Uranium mineralisation is in fine-grained surficial sand and clay, cemented by calcium and magnesium carbonates.
Surficial deposits comprise about 4% of world uranium resources. Calcrete deposits represent 5% of Australia¹s total reserves and resources of uranium. They formed where uranium-rich granites were deeply weathered in a semi-arid to arid climate. The Yeelirrie deposit in WA is by far the world's largest surficial deposit. Other significant deposits in WA include Lake Way, Centipede, Thatcher Soak, and Lake Maitland.
In WA, the calcrete uranium deposits occur in valley-fill sediments along Tertiary drainage channels, and in playa lake sediments. These deposits overlie Archaean granite and greenstone basement of the northern portion of the Yilgarn Craton. The uranium mineralisation is carnotite (hydrated potassium uranium vanadium oxide). Calcrete uranium deposits also occur in the Central Namib Desert of Namibia.
2. Uranium in Galgaduud and South Mudug regions
Apart from the Sepiolite deposits of El-Bur, and unproven reserves of hydrocarbons (oil and gas in the province), the Gal-Mudug Regions of Central Somalia is endowed with another mineral deposit, uranium deposits. Following numerous mineral explorations, the area between Dusa Mareb, El-Bur, Hobya and South Galkayo was found to contain extensive deposits of Uranium in the Taleh Formation that covers Galgaduud and South Mudug Regions. In the Miocene and the Pliocene (the Tertiary), the Taleh Formation had undergone extensive weathering in which secondary mineralization occurred. In this way Uranium minerals were formed in shallow deposits of calcretes and silcrete.
Somalia is known to have resources of uranium. The deposit in Ghelinsor-Elbur area has an estimated resource of 8,000 tons of Uranium Oxide (U3O8) from ore that grades 0.116%. The Wabo-Mirig deposit was estimated to have a resource of 5,500 t of U3O8 from ore that graded 0.08%. Dhusa Mareb had an estimated resource of 3,000 t of U3O8 from ore that graded 0.08% (Chakrabarti, 1988; pp. 95-96). The total uranium metal content of these estimated resources is 14,000 t. Nearly 6,700 t of the country’s uranium resources were estimated to be recoverable at a world market price between $80 – 130 per Kg.
If infrastructure is improved and all-weather roads are built, these resources would be recoverable at a price less than $80 per Kg (World Resources Institute and others; 1996, p. 288).
1. Developments in mining the uranium of Somalia:
Uranium deposits are found in large quantities on some maps generated in the 1970s by Soviet mineralogy surveys in Somalia. These maps showed that Ali Gelle in Buur Hakaba Crystalline basement complex (within a two hundred kilometers west of Mogadishu) as an area where uranium can be mined.
In 1982, LEVICH, Robert A., U.S. Department of Energy from (Yucca Mountain Project, 1551 Hillshire Drive, Las Vegas, NV 89134, bob_levich@ymp.gov.) led the International Atomic Energy Agency (IAEA) to evaluate uranium resources in Somalia.
In 1984, Brazilian mining company, Construtora Andrade Gutierrez announced a $300 million investment in a uranium mine in central Somalia. The deal was to be financed by Banco do Brasil, and the host government agent was the Somali Arab Mining Company (Soarmico). Soarmico was itself a joint venture founded in 1978 between the Somali government, the Arab Mining Company based in Jordan, and Iraq.
But according to a dated World Energy Council report, Somalia has only a sizeable reserve that would be (relatively) expensive to extract. (National Review On-line; 1993)
4. Current mining activities:
Somalia does not have any active uranium mining capabilities or activities, making it impossible for the country to send the mineral to illegal destination or places under UN Security Council sanctions. In addition mining the uranium needs industrial infrastructure which Somalia does not have at the moment due to more than 15 years of civil war. The World Nuclear Association's annual uranium production figures and list of worldwide uranium mining does not mention any production from Somalia.
5. Thoms R. Yager; The mineral industries of Somalia:
Name(s): | Dhusa Mareb - Wabo - Mirig - Wisil- province : El Bur, Dusa Mareb, Wasil | ||||||||||||||||||||||||
Country: | SOMALIA: Gal-Mudug State (An area between Dhusa-mareeb, El-bur, Wasil and Galkayo. | ||||||||||||||||||||||||
Commodity(ies): |
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Main morphology: | Concordant to sub-concordant envelope of disseminated ore | ||||||||||||||||||||||||
Morphology(ies): | Cap, blanket, crust - Concordant to sub-concordant envelope of disseminated ore - | ||||||||||||||||||||||||
Deposit type(s): | Shallow uraniferous deposit - Sediment-hosted uranium; Arlit-type - Calcrete, silcrete - | ||||||||||||||||||||||||
Host rock(s): | Other duricrust : gypscrete, phoscrete, Uranium-bearing duricrust - Silcrete - Calcrete & Dolocrete - Sandstone - Sand - | ||||||||||||||||||||||||
Exploitation type(s): | Mining method: This deposit is not mined. | ||||||||||||||||||||||||
Ages: |
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Status: | Dormant district | ||||||||||||||||||||||||
The Uranium deposits of Gal-Mudug Region in Central Somalia
6. Background:
According to Wikipedia, “Uranium is a chemical element in the periodic table that has the symbol U and atomic number 92. Heavy, silvery-white, metallic, naturallyradioactive, uranium belongs to the actinide series. Its isotopes 235U and to a lesser degree 233U are used as the fuel for nuclear reactors and the explosive material fornuclear weapons. Depleted uranium (238U) is used in kinetic energy penetrators andarmor plating.”
Natural uranium metal contains about 0.71% U-235, 99.28% U-238, and about 0.0054%U-234. In order to produce enriched uranium, the process of isotope separation removes a substantial portion of the U-235 for use in nuclear power, weapons, or other uses. The remainder, depleted uranium, contains only 0.2% to 0.4% U-235. Because natural uranium begins with such a low percentage of U-235, the enrichment process produces large quantities of depleted uranium. For example, producing 1 kg of 5% enriched uranium requires 11.8 kg of natural uranium, and leaves about 10.8 kg of depleted uranium with only 0.3% U-235 remaining.
Its two principal isotopes are 235U and 238U. Naturally-occurring uranium also contains a small amount of the 234U isotope, which is a decay product of 238U. The isotope 235U or enriched uranium is important for both nuclear reactors and nuclear weaponsbecause it is the only isotope existing in nature to any appreciable extent that is fissile, that is, fissionable by thermal neutrons. The isotope 238U is also important because it absorbs neutrons to produce a radioactive isotope that subsequently decays to the isotope 239Pu (plutonium), which also is fissile.
The artificial 233U isotope is also fissile and is made from thorium-232 by neutronbombardment.
Uranium was the first element that was found to be fissile. Upon bombardment with slow neutrons, its 235U isotope becomes the very short lived 236U which immediately divides into two smaller nuclei, releasing nuclear binding energy and more neutrons. If these neutrons are absorbed by other 235U nuclei, a nuclear chain reaction occurs and, if there is nothing to absorb some neutrons and slow the reaction, the reaction is explosive. The first atomic bomb worked by this principle (nuclear fission). A more accurate name for both this and the hydrogen bomb (nuclear fusion) would be "nuclear bomb" or "nuclear weapon", because only the nuclei participate.
7. Uses
After the discovery in 1939 that it could undergo nuclear fission, uranium gained importance with the development of practical uses of nuclear energy. The first atomic bomb used in warfare, "Little Boy", was a uranium bomb. This bomb contained enough of the uranium-235 isotope to start a runaway chain reaction which in a fraction of a second caused a large number of the uranium atoms to undergo fission, thereby releasing a fireball of energy.
The main use of uranium in the civilian sector is to fuel commercial nuclear power plants. Generally this is in the form of enriched uranium, which has been processed to have higher-than-natural levels of 235U and can be used for a variety of purposes relating to nuclear fission. Commercial nuclear power plants use fuel typically enriched to 2–3% 235U, though some reactor designs (such as the Candu reactors) can usenatural uranium (unenriched, less than 1% 235U) fuel. Fuel used for United States Navysubmarine reactors is typically highly enriched in 235U (the exact values are classified information). When uranium is enriched over 85% it is known as "weapons grade". In abreeder reactor, 238U can also be converted into plutonium.
8. Uranium as source of nuclear energy:
Currently the major application of uranium in the U.S. military sector is in high-density penetrators. This ammunition consists of depleted uranium alloyed with 1–2% other elements. The applications of these armor-piercing rounds range from the 20 mmPhalanx gun of the U.S. Navy for piercing attacking missiles, through the 30 mm gun inA-10 aircraft, to 105mm and larger tank barrels. At high impact speed, the density, hardness, and flammability of the projectile enable destruction of heavily armored targets. Tank armour and the removable armour on combat vehicles are also hardened with depleted uranium (DU) plates. The use of DU became a contentious political-environmental issue after US, UK and other countries' use of DU munitions in wars in the Persian Gulf and the Balkans raised questions of uranium compounds left in the soil.
Occurrence in Gal-Mudug regions of Central Somalia
Uranium ore is rock containing uranium mineralisation in concentrations that can be mined economically, typically 1 to 4 pounds of uranium oxide per ton or 0.05 to 0.20 percent uranium oxide.
Naturally occurring uranium is composed of three major isotopes, 238U, 235U, and 234U, with 238U being the most abundant (99.3% natural abundance). All three isotopes are radioactive, creating radioisotopes, with the most abundant and stable being 238U with a half-life of 4.5 × 109 years, 235U with a half-life of 7 × 108 years, and 234U with a half-life of 2.5 × 105 years. 238U is an α emitter, decaying through the uranium natural decay series into 206Pb.
References:
1. Chakrabarti, A.K., 1988. An appraisal of the mineral potential of the Somali Democratic Republic: Mogadishu, Somalia: The United Nations Revolving Fund for Natural Resources Exploration, 230 p.
2. M. Siad (1989): Application of geostatistical techniques in the evaluation of Wabo uranium deposit, Galgudud region, central Somalia. ITC Journal 1989-1, Enschede, the Netherlands.
3. M. O. Childers, and R. V. Bailey; Classification of uranium deposits, Rocky Mountain Geology; October 1979; v. 17; no. 2; p. 187-199.
4. World Resources Institute, United Nations Environment Programme, UNDP and World Bank, 1996. World Resources, 1996 – 1997, Oxford, UK, Oxford Press, p. 365
