Mineral Resources Potential - Geothermal Resources

142 Mineral Resourocs Potential of Ethiopia
golf-clubs, and bicycle frames, and have been successfully
employsd in reinforced concrete (Noetstaller, 1 98 8).
Graphite deposits in Ethiopia
The meta-sedimentary rocks in Sidarno, Haramghe, Wollega and
Tigray are potential sources for graphite. A series of Iong belts of
graphitic schist extends for tens of kms through the Kenticha and
Kibre Mengist areas of the Adola Belt and in Soka, and Kunni
valley of the Chercher Mountain with large greenschist series. The
graphite in Moyale area is hosted by quartz-feldsp-mica schists
and quartzites which gendl y form continuous bodies extending
for hundreds of meters, The .Moyale graphite deposit has an
estimated reserve of 0.46 Mt of graphite (Mengistu and Fentaw,
2000).
- - 4.11 Silica
The chemical compund silicon dioxide, also known as silica, is
the oxide of silicon, chemical formula Si@. Siliceous is an
adjective meaning "referri6 to silica". Silica is found in nature in
( aB$; several forms, including quartz and opal. In fact, it has 17
I . .I'
crystalline forms. The most oornmon constituent of sand in inland
continental settings and non-mpical coastal settings is silica,
usually in the form of quartz because the considerable hardness of
this mineral resists erosion, However, the composition of sand
varies according to local rock sources and conditions. Variants
found in high-pressure impacts are mite and stishovite. Many
rrns of life contain silica structures (Biogenic Silica), including
icro-organisms such as diatoms, plants such as horsetail, and
mds such as hexactinellid sponges. It is present in the cell walls
virious plants (including edible ones) to strengthen their
ctural integrity. '