Mineral Resources Potential - Geothermal Resources

120 Mind Reuwrces Potential of Ethiopia
water-rich phases of complete crystalisation of granite melts. This
fluid is forced into the interstitial spaces of the granite and pools at
the upper margins, here boiling and alteration occur.
3.9 Radioactive mineral (Uranium, Thorium) deposits
Udum is a naturally occurring element found in low levels
witkin all rocks, soils, and water. This is the highest-numbered
element to be found naturally in significant quantities on earth. It: is
considered to be more plentiful than antimony, beryllium,
cadmium, gold, mercury, silver, or tungsten and is abut as
abundant as arsenic or molybdenum. It is found in many minerals
including waninite (the most common uranium ore), smite,
uranophane, torbernite, and coffinite. Significant concentrations of
~miwn occur in some substances such as phosphate rocks, and
minerals such as tantalite, lignite, and monazite sands also contain
uranium-rich ores (It is recovered commercially from these
sources) (Jensen and Bateman, 1979). The decay of uranium,
thorium and potassium40 in the Earth's mantle is thought to be the
main source of heat that keeps the outer core liquid'and drives
mantle convection, which in tub drives plate tectonics. Uranium
ores, i.e. mks containing uranium mineralisation in concentrations
that can be mined economically, typically give I to 4 pounds of
uranium oxide per ton, or 0.05 to 0.20 % uranium oxides.
Origin
Uranium deposits are usually sourced from radioactive granites,
where certain minerals such as monazite are leached during
hydrothermal activity or during circulation of groundwater, The
uranium is brought into solution by acidic conditions and is
deposited when this acidity is neutralized. Generally, this occurs in
certain carbon-bearing sediments, within an unconformity in
sedimentary strata. Uranium has a large atom that does not "fit"