Mineral Resources Potential - Geothermal Resources

1 30 Mineral Rqmm Potential &Ethiopia
throughout are late Tertiary and Quaternary. The largest deposit h
situated about 17 km north-east of the town of Gewane (lati*
10~14' 30"N and longitudes*40~ 35'40"E and #*35'30"~)
mupying an area of 6.5 km2. The reserves at this site have been
estimated at 77 Mt by EGS. The average thickness of the bentonite
cl L y is about 13.8 m. The second largest deposit is Wolrseisa
si ted 1-3 krn north of DessisAssab highway been the
Badona River and Warseisa. The bentonite deposit occupies an
area of about 127 ktn2. The reserves have been athated to be
over 7 Mt and the average thickness is about 5.6 m.
The Ledi deposit is situated dong the Addis-Assab
highway about 30 km south of the Dessie junction, It is bounded
by latitude l.lO1O'OO"-1 1'1 3'20" and longitudes 40~42'00'"-
40°47~". In the area, east and west of the highway, the clay is
calculated to outcrop over an area of 557,000 m2. At Ledi, the
average thickness of the bentonitic bed is estimated to 3.2 m and
, reserves have'been calculated to 1.78 Mt; the total reserves in the
&a-have been estimated to 7 Mt (Mengistu and Fentaw 2000).
Much-higher-qdity deposits of bentonite Rave been found
at Lake Abaya in Sidamo. ~ hk 'bentonite-bearing beds are part of
lacustihe sediments, which consist of clays, salt-bearing beds,
sandstones, calcareous sandstones, conglomerates aud interbedded
volcaniclastic rocks, They result, following Mengistu and Fentaw
(20001, fiorn the dieration of glassy magmatic materials. The
s in the ~idioho Island (Lake Abaya, Rift Valley) are
ed to be 6.4 Mt (EGS, 1989).
-4 Other clays and kaolin
Clay deposits are formed h m the weathering of feldspar bearing
ocks, such as granites, pegmdtes, gneiss or sandstone and
olcanics, volcaniclastics and sediments. Kaolin results from the
weat hering of granite and gneiss feldspar-related rocks and from