GEP  Vol.3 No.4 , June 2015
Geophysical Interpretation of Possible Gold Mineralization Zones in Kyerano, South-Western Ghana Using Aeromagnetic and Radiometric Datasets
Abstract
Airborne magnetic and radiometric datasets are used to interpret the geology and geological structural patterns which serve as potential gold mineralization zones in the Kyerano area located at south-western boundary of the prospective Sefwi Gold Belt and the Kumasi Basin in south-western Ghana. The geophysical data processing approach adopted concentrated on mapping geological boundaries, geological structures and possible gold mineralization zones is link to hydrothermally altered zones. The application of the enhancement filtering algorithms such as the reduction to the pole and analytic signal to the magnetic data, as well as the ternary radiometric image aided in the mapping of the mafic metavolcanics, basin metasediments and the belt-type granitoid complexes. The first vertical derivative and tilt angle derivative filters helped to delineate fractures, folds, and the contact zones of the formations such as that of the metavolcanics-metasediments that host the main Bibiani Shear Zone. Lineament analysis of the structures using rose diagram, reveals two main tectonic episodes in the area. These are NE-SW and NNW-SSE trending regional structures which account for about 90% of the extracted structures and are associated with the D1 and D2 deformational episodes of the Birimian Formation respectively. These structures are major fracture systems and play a pivotal role in the localization of gold mineralization in the study area.

Cite this paper
Wemegah, D. , Preko, K. , Noye, R. , Boadi, B. , Menyeh, A. , Danuor, S. , Amenyoh, T. (2015) Geophysical Interpretation of Possible Gold Mineralization Zones in Kyerano, South-Western Ghana Using Aeromagnetic and Radiometric Datasets. Journal of Geoscience and Environment Protection, 3, 67-82. doi: 10.4236/gep.2015.34008.
References

[1]   World Gold Council (2010) The10-Years Gold Bull Market in Perspective.

[2]   Amankwah, R.K. and Anim-Sackey, C. (2003) Strategies for Sustainable Development of the Small-Scale Gold and Diamond Mining Industry of Ghana. Resources Policy, 29, 131-138.
http://dx.doi.org/10.1016/j.resourpol.2004.07.002

[3]   Bloch, R. and Owusu, G. (2012) Linkages in Ghana’s Gold Mining Industry: Challenging the Enclave Thesis. Resources Policy, 37, 434-442.
http://dx.doi.org/10.1016/j.resourpol.2012.06.004

[4]   Hilson, G.M. (2004) Structural Adjustment in Ghana: Assessing the Impacts of Mining-sector Reform. African Affairs, 54-77.
http://dx.doi.org/10.1353/at.2005.0006

[5]   Aubynn, A.K. (1997) Liberalism and Economic Adjustment in Resource Frontiers: Land-Based Resource Alie Nation and Local Responses. A Reflection from Western Ghana. Working Paper 9/97. Institute for Development Studies, University of Helsinki, Helsinki.

[6]   Keating, P.B. (1995) A simple Technique to Identify Magnetic Anomalies Due to Kimberlite Pipes. Exploration and Mining Geology, 4, 121-125.

[7]   Boadi, B., Wemegah, D.D. and Preko, K. (2013) Geological and Structural Interpretation of the Konongo Area of the Ashanti Gold Belt of Ghana from Aeromagnetic and Radiometric Data. International Research Journal of Geology and Mining, 3, 124-135.

[8]   Graham, K.M., Preko, K., Wemegah, D.D. and Boamah, D. (2013) Geological and Structural Interpretation of Part of the Buem Formation, Ghana, Using Aerogeophysical Data. Journal of Environment and Earth Science, 4, 17-31.

[9]   Lo, B.H. and Pitcher, D.H. (1996) A Case History on the use of Regional Aeromagnetic and Radiometric Data Sets for Lode Gold Exploration in Ghana. Annual Meeting Expanded Abstracts, Society of Exploration Geophysicists, 592-595.
http://dx.doi.org/10.1190/1.1826712

[10]   Reynolds, R.L., Rosenbaum, J.G., Hudson, M.R. and Fishman, N.S. (1990) Rock Magnetism, the Distribution of Magnetic Minerals in the Earth’s Crust and Aeromagnetic Anomalies. US Geological Survey Bulletin, 1924, 24-45.

[11]   Kesse, G.O. (1985) The Mineral and Rock Resources of Ghana. A.A. Balkema, Rotterdam.

[12]   Rajesh, V.J., Yokoyama, K., Santosh, M., Arai, S., Oh, C.W. and Kim, S.W. (2006) Zirconolite and Baddeleyite in an Ultramafic Suite from Southern India: Early Ordovician Carbonatite-Type Melts Associated with Extensional Collapse of the Gondwana Crust. The Journal of Geology, 114, 171-188.
http://dx.doi.org/10.1086/499571

[13]   Case, J.E., and Sikora, R.F. (1984) Geologic Interpretation of Gravity and Magnetic Data in the Salida Region, Colorado. US Geological Survey Open-File Report, 46, 84-372.

[14]   Wilford, J.R., Bierwirth, P.N. and Craig, M.A. (1997) Application of Airborne Gamma-Ray Spectrometry in Soil/Regolith Mapping and Applied Geomorphology. AGSO, Journal of Australian Geology and Geophysics, 17, 201-216.

[15]   Hirdes, W., Senger, R., Adjei, J., Efa, E., Loh, G. and Tetty, A. (1993) Explanatory Notes for the Geological Map of Southwest Ghana 1:100,000, Sheet Wiawso (0603d), Asafo (0603c), Kukuom (0603b), Goaso (0603a), Sunyani (0703d) and Berekum (0703c). Geologisches Jahrbuch Reine B, Band B 83, Hannover, 139 p.

[16]   Griffis, R.J. (1998) Explanatory Notes-Geological Interpretation of Geophysical Data from South-Western Ghana. Minerals Commission, Accra, 51 p.

[17]   Grasty, R.L. (1976) Applications of Gamma Radiation in Remote Sensing. In: Schanda, E., Ed., Remote Sensing for Environmental Sciences, Springer Verlag, Berlin, 257.
http://dx.doi.org/10.1007/978-3-642-66236-2_7

[18]   Milligan, P.R. and Gunn P.J. (1997) Enhancement and Presentation of Airborne Geophysical. AGSO, Journal of Australian Geology and Geophysics, 17, 64-74.

[19]   Geosoft Inc. (1996) OASIS Montaj Version 4.0 User Guide. Geosoft Incorporated, Toronto.

[20]   Geosoft Inc. (1995) OASIS Montaj Airborne Radiometric Processing System Version 1.0 User’s Guide. Geosoft Incorporated, Toronto.

[21]   Ansari, A.H. and Alamdar, K. (2009) Reduction to the Pole of Magnetic Anomalies Using Analytic Signal. World Applied Sciences Journal, 7, 405-409.

[22]   Debeglia, N. and Corpel, J. (1997) Automatic 3-D Interpretation of Potential Field Data Using Analytic Signal Derivatives. Geophysics, 62, 87-96.
http://dx.doi.org/10.1190/1.1444149

[23]   Silva, A.M., Pires, A.C.B., Mccafferty, A., de Moraes, R.A.V. and Xia, H. (2003) Application of Airborne Geophysical Data to Mineral Exploration in the Uneven Exposed Terrains of the Rio Das Velhas Greenstone Belt. Revista Brasileira de Geociências, 33, 17-28.

[24]   Ostrovskiy, E.A. (1975) Antagonism of Radioactive Elements in Well Rock Alteration Fields and Its Use in Aerogamma Spectrometric Prospecting. International Geological Review, 17, 461-468.
http://dx.doi.org/10.1080/00206817509471687

[25]   Nabighian, M.N. (1984) Toward a Three-Dimensional Automatic Interpretation of Potential Field Data via Generalised Hilbert Transforms: Fundamental Relations. Geophysics, 49, 780-789.
http://dx.doi.org/10.1190/1.1441706

[26]   Manu, J. (1993) Gold Deposits of Birimian Greenstone Belt in Ghana: Hydrothermal Alteration and Thermodynamics. PhD Thesis, Braunschweiger Geologisch-Palaontologische Dissertationen, Vol. 17, Braunschweig.

 
 
Top