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UNDISCOVERED URANIUM RESOURCES
IN GHANA
1
Samuel B. Dampare1,2, Thomas K. Adu3, Akwasi B.
Asumadu-Sakyi2,
1Graduate School of Nuclear and Allied Sciences, University of Ghana-
Atomic, P.O. Box LG 58, Legon-Accra, Ghana
2National Nuclear Research Institute, Ghana Atomic Energy
Commission,
P.O. Box LG 80, Legon-Accra, Ghana
3Ghana Geological Survey Department, Accra, Ghana
IAEA WORKSHOP ON ‘‘APPLICATION OF UNITED NATIONS FRAMEWORK CLASSIFICATION-2009
(UNFC-2009) FOR URANIUM RESOURCES’’JOHANNESBURG, SOUTHAFRICA, 10 – 14 NOVEMBER, 2014
INTRODUTION
2
INTRODUCTION CONT’D
3
Ghana is endowed with mineral resources
Major mineral resources: gold, diamonds, manganese, bauxite and
oil
Gold is predominant mineral accounting for about 80 % of all
mineral revenues.
Unexploited or least exploited deposits: iron ore, limestone, brown clays, kaolin, mica, columbite-tantalite, feldspar, silica sand and quartz.
Minor deposits: ilmenite, magnetite and rutile.
Ghana discovered about one (1) billion barrels of offshore oil in 2007.
Insufficient energy to support the growing population and industrial activities
Ghana is, therefore, embarking on nuclear power project to introduce nuclear energy into the country’s energy mix
The need to explore for radioactive minerals cannot be overemphasized
GEOLOGICAL SETTING
4
Adopted after Attoh et al., 2006
5
HISTORY OF EXPLORATION FOR RADIOACTIVE
MINERALS IN GHANA
DATE ACTIVITY INVESTIGATORS/FUNDED AGENCIES
FINDINGS AND REMARKS
1952 First attempt of radioactive
minerals prospecting
D. Ostle, P.H. Hale plus a
Geologist from Gold Coast
Geological Survey Dept.
In most rocks, thorium content was about 0.1
% and uranium content was not remarkable
1953-
76
Geochemical survey,
Radiometric surveys,
Individuals., Gold Coast
Geological Survey Dept.,
Uranerzbergbau (GmbH)
International Atomic Energy
Agency
• Uranium-bearing pegmatites in the Cape
Coast area were of no economic
significance.
• Low possibility of discovering large and
easily obtainable uranium deposit in
crystalline areas of Ghana.
• The Tarkwa complex unfavourable for
development of uranium deposits.
• Prospecting efforts should be focused on
sedimentary formations of the Voltaian, in
an attempt to discover a sandstone-type
uranium deposit.
• The syenites contained small quantities of
thorium and uranium minerals (allanite
and pyrochlore) with extremely low
grade.
• Areas of higher radioactivity were
situated on top of syenites and nepheline-
syenites of the Dahomeyan.
HISTORY OF EXPLORATION FOR
RADIOACTIVE MINERALS IN GHANA CONT’D
6
DATE ACTIVITY INVESTIGATORS/FUNDED AGENCIES
FINDINGS AND REMARKS
1982
Evaluation of
potential
deposits in
Ghana
International Uranium
Resources Project
(IUREP)
• Dahomeyan Formation– major uranium target due to its
occurrence in the Pan African-Brazilian mobile belt
• Voltaian Supergroup – similar age to the Taoudeni Basin
in Guinea and has the potential to host uranium deposits
• Eburnean Granites – host known deposits and may host
further similar types.
• Tarkwaian Group – the conglomerates have the potential
to host uranium similar to the palaeoplacer deposits in
South Africa
• Togo and Buem Structural Units – no potential
• Coastal basins – low potential
• Palaeozoic Accraian and Sekondian Series – low potential
• Cretaceous and Tertiary basins – low potential
• Birimian Formation – low potential
RECENT URANIUM EXPLORATION-RELATED
ACTIVITIES
7
DATE ACTIVITY INVESTIGATORS/FUNDED AGENCIES
FINDINGS AND REMARKS
2008 Uranium content study
at Biakpa, Volta Region
using Track Etch
technique
Osborne C. Oppon and Akwasi
B. Asumadu-Sakyi of Ghana
Atomic Energy Commission
Mean percentage concentration of uranium in
rocks was 0.018 %.
2010 Airborne Geophysical
Surveys of the Voltaian
and Keta Basins
EU-funded Mining Sector
Support Programme (MSSP)
Anomalous areas for uranium potential were
identified.
2011-
2012
Follow-ups on Airborne
geophysical Anomalies
of the Voltaian Basin
Geological Survey
Department, Ghana
All the rocks analyzed had uranium
concentration below 10 ppm (< 10 ppm)
8
2
4 3 1
POTENTIAL HOST ROCK TYPES FOR URANIUM DEPOSITS IN
GHANA (INFERENCE FROM IUREP REPORT, 1982)
9 GAMMA-RAY SPECTROMETRY DATA) MAGNETIC FIELD ANOMALY
AIRBORNE GEOPHYSISICAL SURVEYOF THE
VOLTAIAN AND KETA BASINS
10 GEOTEM AIRBORNE ELECTROMAGNETIC
SURVEY
AIRBORNE GEOPHYSISICAL SURVEYOF THE
VOLTAIAN AND KETA BASINS CONT’D
FREE-AIR GRAVITY FIELD
FOLLOW –UPS ON AIRBONE ANOMALIES
11
SAMPLE CODING
12
THE WAY FORWARD/FUTURE PLANS
• Geological Survey Department (GSD) is currently carrying out
ground follow-ups on the anomalies identified by airborne
geophysical surveys
• Anomalous areas of uranium concentration need to be well defined
• Prospectivity modelling approach, proposed by the British Geogical
Survey, is being considered for the sandstone-hosted uranium in the
Voltaian Basin
• Three areas have been targeted in the Voltaian Basin:
northern, western area and southern parts
• Strengthening collaboration among GSD, Ghana Atomic Energy
Commission and University of Ghana to continue with the uranium
exploration activities
• Have a national project on uranium exploration
• Step up public education on uranium and nuclear power issues
13
CHALLENGES AND NEEDS
• Inadequate funds for ground follow-ups on anomalous areas
• Lack of equipment for effective ground follow-ups
Continued support from the IAEA would be required in the following areas:
TC Project on Uranium Exploration in Ghana
Expert Advice/Mission
Further training course in uranium exploration techniques and methods
Equipment to support the GSD/GAEC/UG exploration team
Image Analyzers for Nuclear Track Counting
Track Etch Detectors
Spark Counter Spectroscopy Amplifiers
Broadband Gamma-Ray Scintillometers
Portable Gamma-Ray Spectrometers D25A-400A
14
CONCLUSIONS
• Although Uranium prospecting in Ghana started in the early days, it
did not yield any economic viable deposits of the mineral
• Recent studies have shown that Ghana stands a high chance of
striking Uranium deposit
• Airborne surveys carried out to cover the entire country had
identified some anomalous potential areas for radioactive mineral
deposits, particularly in the Voltaian and Keta Basins
• Ground investigations are being carried out by the Geological
Survey Department together with Ghana Atomic Energy
Commission
• Preliminary geochemical results from the Voltaian Basins are not
encouraging therefore further studies are to be carried out
• Geochemical studies are to be conducted at potential areas such as
Dahomeyan formation
15
APPLICATION OF UNFC-2009 TO EXPLORATION
PROJECT OF GHANA
16
Deposit
/
Project
Investigator UNFC-
2009
Class
UNFC
-2009
Sub-
Class
UNFC-2009
Categories
Remarks
E F G
Voltaian
Basin
Explorat
-ion
Ghana Geological Survey Department
Exploration project
None 3.2 3 4 Early
Exploration
17
THANK YOU