Marble in Ethiopia - gse.gov.et

Transcription

Marble in Ethiopia - gse.gov.et
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Marble has been mined in many
parts of Ethiopia since ancient
times and the deposits are inexhaustible. There is a wide range of
colours and the quality is supreme.
The quality is so good that Ethiopia
has a significant export to the marble country par excellence of Italy.
Numerous extensive deposits of marble are
generally hill forming and occur throughout northern and western Ethiopia. The
marble deposits are part of mediumgrade, metasedimentary successions of
the different Precambrian greenstone
complexes. The marbles occur as strikeparallel lenses (presumably reflecting fold
patterns), intercalated with amphibolite,
quartzite and schists. The metasedimentary rocks are affected by granitic, mafic and
ultramafic intrusions.
Most of the marble is white to grey,
coarse-grained calcitic with calcite contents of 98%. All marble deposits are jointed and fractured. Locally the fracture systems are closely spaced but often joint systems occur with spacing between 2–3 m,
making quarrying of large blocks feasible.
Most marble deposits contain billions of
tons of high-quality marble. The Ethiopian
marbles vary within a large colour spectrum. Pure white marble is common
together with grey, greenish, pink and sky
blue varieties.
Marble is quarried for a variety of
architectural and artistic purposes in
Ethiopia. In a large number of quarries,
the marble is extracted by small-scale
operations using hand-held drill hammers and wedges as primary tools, no
sophisticated methods such as blasting
and/or sawing are used. The maximum
weight of blocks mined by small-scale
enterprises is about one ton. In some of
the marble quarries, for instance the
large Daleti marble quarry, diamond
chain sawing is used to produce very
large blocks for export.
Daleti
Mankush
Baruda
(Moye,
Gewi &
Ekonte)
Bulen &
Ganzi
Daleti
Newi Naedir
Akmara
Kelafinos
Taget
Enda Tikur
Berdada
Lake
Tana
ft
Addis Ababa t
E
an
Ri
oi
p
hi
n
ai
M
High-grade Precambrian
Undifferentiated gneisses
and schists
Low-grade Precambrian
Metavolcano-sediments
Metaultramafic-mafics
Precambrian
Phanerozoic Intrusives
Gabbro
Diorite
Granite-tonalite
Palaeozoic Rocks
Tillites
Mesozoic Rocks
Undifferentiated sediments
Geology: Modified from Mengesha et al.(1996)
Geological map of Ethiopia, second edition, 1:2,000,000
MINERAL RESOURCES OF
Marble in Ethiopia
Cenozoic Rocks
Early-Mid Tertiary basalt
Upper Tertiary-Quaternary - basalt
Mid Tertiary-Quaternary - felsic rocks
Early Tertiary sediment
Upper Tertiary-Quaternary sediment
Simplified geological map of Ethiopia with localities of marble the Western and Northern parts of the country.
Some of the marble is used locally for
dimension stones, whereas the main production is for export. One of the main
importers of Ethiopian marble is Italy,
known as the marble-producing country
par excellence, which indicates that the
imported Ethiopian marble matches the
famous Carrara marble; for centuries the
Carrara marble has supplied not only
Europe but also other continents with
high-class material for tiles, slabs and
sculptures.
Ethiopia is endowed with marble
occurrences, a number of which have
been explored and quality tested. So far
only a limited number of marble deposits
have been exploited, so the potential in
Ethiopia for further expansion of marble
production and export is huge.
Daleti marble deposit
The deposit is named after the town
Daleti, 635 km west of Addis Ababa. The
deposit is one of the best known marble
deposits which have been exploited for a
long period of time. The deposit is flat to
hill forming and generally exhibits a variety of colours ranging from white, dark
grey, pink, blue and green patches.
The ‘multicolour’ blue and pink varieties are rare. The pink, silicate rich marble and sky blue marble occur around
contact zones with basic dykes. Like the
variations in colour, there are also different grain sizes: Coarse-grained marble
with minor graphitic bands, coarsegrained graphitic marble with white
bands and white fine-grained green to
grey patches. The marbles are calcitic
with minor amounts of dolomite,
graphite, quartz and micas. This deposit
is explored by the National Mining
Company. The company uses highly
sophisticated technologies where both
cutting by diamond wire and water jet
are applied.
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Ministry of Mines of Ethiopia
MINERAL RESOURCES OF
Dear Investors,
We take this opportunity to welcome you
to Ethiopia.
We promise to make every possible effort
to provide you with all required information on the mineral sector in Ethiopia.
Photo of Daleti marble outcrops in the foreground and a large forest clad hill of first class marble.
If you require information on the mining
law, licensing conditions and the invest-
Mankush marble deposit
This is a large marble deposit situated some
700 km west of Addis Ababa. It occurs in a
Precambrian metamorphic complex consisting of metasedimentary rocks alternating
with amphibolites. The complex has been
deformed many times, subjected to highgrade metamorphism and later intruded by
granites and a variety of ultramafic bodies.
Most of the outcropping marble has joints
with spacings up to 3 m and well suited for
extracting large blocks.
The Mankush marbles range in colours
from white with grey veins, grey with white
veins and locally to pink varieties. Dark
graphitic bands are locally dominating.
Some of the marble outcrops are explored
by Ethio-marble Industry and Berta
Construction. Large blocks are extracted by
pneumatic hand-drill hammers, wedges and
jacks. The extracted blocks are trucked to
Addis Ababa for further processing.
No large-scale mining has yet been initiated in this marble deposit in spite of its obvious high quality and easy accessibility.
ment climate in Ethiopia, please contact
the Mineral Licensing and Administration
Department:
Ministry of Mines
Mineral Licensing and Administration
Department
P.O. Box 486
Addis Ababa, Ethiopia
Tiles of marble from Mankush showing range of
Tel. +251 11 6461214
colours on a background of sky blue marble.
Fax +251 11 6463454
Email: information@mome.gov.et
www.mome.gov.et
Marble occurrences and deposits
The marble occurrences are found within the
Precambrian basement rocks of the country,
especially in the low grade meta-sedimentary and meta-volcanics of northern(Kelafinos,
EndaTikur, Newi, Akmara, Naedir, Berdada,
Taget, Adiwoyane, Eminzong marble deposits),
western (Mora and Bapuri, Bulen, Ganzi,
Baruda, Mankush and Daleti marble deposits). These marble deposits are identified
potential for dimension-stone supply.
If you require information on the geology
and mineral opportunities in Ethiopia,
please contact the Geological Survey of
Ethiopia (GSE):
Geological Survey of Ethiopia
P.O. Box 2303
Addis Ababa, Ethiopia
Tel. +251 6 463325
Fax +251 6 463326
Quarry in Daleti marble where
Email: Survey@ethionet.et
huge blocks are extracted using
www.geology.gov.et
diamond chain saws.
We are looking forward to your mining
investment in Ethiopia.
Prepared with assistance from GEUS.
December 2010