Mineral Resources Potential - Geothermal Resources

Metallic Minds 119
sediments over the Precambrian bament (e,g+ Soka, Ijabq
Ramis River in Wolfega and AfFmtu and Grava) may represent
Red Bed type or carbonate-hosted base-metal deposits. This type
of mineralization warrants further investigations.
I
Molybdenum (as molybdenite) occurs in leucocratic quartzplagioclase
acidic rocks at a flank of granite batholiths at Fakusho.
Some granitic pegmatites also contain Mo (Bissidimo valley,
Chiltu). Wolfram occurs with Mo in granitic rocks at Kata
(Wollega); this element is also commonly identified as trace
dement in numemu shear-zone related mesothermal gold deposits
(e.g. Digati, East SWo, and Korkora in Adola), Other
molybdenum occurrences have been reported in Bissidimo River
valley 13 km hm the town of 'Ham. The Mo is associated with
quartz veins. The quartz veins confining Mo mineral occurs in
pegnmites. Similar occurrences has been also found in Dedessa
River (Wollega) associated with pegmatites, The scarcity of
si-cant base-metals deposits in Ethiopia may k due to a lack of
systematic exploration. Therefore, systematic exploration is
required to asses the base-metals potential of the country.
Molybdenum, Tin, and tungsten 4 s generally form in a
certain type of granite, via a similar mechanism to intrusive-related
gold and copper. They are considered together because the process
of fuming these deposits is essentially the same. Skarn type
mindisation related to these granites is a very important type of
tin, tungsten and molybdenum deposit. Slam deposits form by
reaction of minedised fluids from the granite reacting with wall
rocks such as limestone. S h mineralisation is also important in
lead, zinc, copper, gold and occasionally uranium minerahation.
Greisen granite is another related tin-molybdenum and
topaz mineralisat ion style. Greisens are formed by endoskam
alteration of granite during the cooling stages of emplacement.
Greisen fluids are formed by gyanites as the last highly gas- and