Geological Mapping and Gold Prospecting of Wadi Umm Beckol-Wadi Akasha Area, Northern Sudan Based on Remote Sensing
[1]
Babiker I. S., Department of Geology, University of Khartoum, Khartoum, Sudan.
[2]
Elsayed Zeinelabdein K. A., Department of Geology, Faculty of Petroleum and Minerals, Alneelain University, Khartoum, Sudan.
[3]
El Nadi A. H., Department of Geology, University of Khartoum, Khartoum, Sudan.
Digital Image processing and GIS applications have been successfully utilized as major tools in mapping and prospecting for gold mineralization in the arid area of Wadi Umm Beckol-Wadi Akasha, northern Sudan. Geological traverses and way points for geological observations and sampling were plotted in the digitally enhanced Landsat TM+ imagery pre-field and a preliminary geological map was prepared. Ground checks helped in the preparation of the final regional geological map at the scale of 1:50000. The main elements of geology were found to include high-grade gneisses; low-grade green schist island-arc assemblage of metasediments, metavolcanics and ophiolitic tectonic mélanges. The layered sequences-mentioned above- are intruded by syn-orogenic, I-type and post-orogenic, A-type granites; and are separated by structural contacts. In this study, at least two styles of gold mineralization were identified. One style is the auriferous (gold-bearing) talcose schist within an ophiolitic tectonic mélange in the extreme south of the study area. These rocks appear pale pink-brown and light green in the 7, 4, 2 and 7, 5, 4 colour composite images; respectively. Two similar linear talcose schists were easily identified in the processed images and were confirmed by ground checks. Also, highly silicified carbonate graphitic schists occur within the metasediments, which were suspected to be highly altered serpentinites. Samples analyzed by fire assay were found to be auriferous. Similar two additional bands were easily distinguished and mapped making use of their characteristic light greenish blue colour in the 7, 4, 2; and dark – light blue colour in the 7, 5 ,4 colour composites. Furthermore, auriferous, sheared and silicified metavolcanics were easily identified as they appear reddish brown in the 7, 4, 2; and pale green in the 7, 5, 4 colour composites. So, geological mapping and prospecting for certain styles of gold mineralization can be successfully achieved through remotely-sensed criteria in arid zones such as the study area, where there is no vegetational cover to interfere with the signals. Indeed, interpretations must be supported by field check and laboratory studies.
Geological Mapping, Gold Mineralization, Landsat 7 ETM+, Image Processing, GIS, Arid Region
[1]
Grabham, G.W., (1916). The geology of Umm Nabardi gold mine. Geological Survey D. Open files.
[2]
Grabham, G. W., (1918). Notes on closing down of Umm Nabardi gold mine. Geological Survey D. Open files.
[3]
Dunn, S.G., (1917). Umm Nabardi gold mine. Geological Survey D. Open files.
[4]
Andrew, G., (1951). Abusari Mine, Geological Survey D. Open files.
[5]
Hume, W. F., (1934). The Geology Egypt.Vol. 2. The fundamental Pre-Cambrian rocks of Egypt and The Sudan: their distribution, age and character. Part I. The metamorphic rocks. Gov. press: Cairo, 300pp.
[6]
Berry, L. & Whiteman, A. J. (1968). The Nile in the Sudan. Geog. rl. J, 134, 1-37.
[7]
Vail, J. R., (1972). Pre-Nubian tectonic trends in northeastern Sudan. J. geol. Soc. London, 128, 21-31.
[8]
Vail, J. R., Dawoud, A.S., Ahmed A., (1973). Geology of the third cataract, Haifa District, Northern Province, Sudan Bull. Geol.Miner.Resour.Sudan 22,1-34.
[9]
Adli, A. A., (1998). Sudan Industrial Minerals and Rocks.Strategic Studies Series. Centre for Strategic Studies, Khartoum - Sudan (Publishers), P. 13-23.
[10]
Schandelmeier, H., Darbyshire, D. P. F., Harms, U., Richter, A., (1988). The E Saharan craton: Evidence for pre-Pan-African crust in NE Africa W of the Nile. In: El Gaby, S., Greiling, R. O. (Eds.). The Pan-African belts of NE Africa and Adjacent areas. Friedr Vieweg and Sohn. P. 69-94.
[11]
Higazy, A. A. A. (1991). Geology of the western portion of the Arabian-Nubian Shield,A study of the Abu Sari Area,Halfa District, Northern Province, Sudan. Mphil, thesis, Portsmouthpolytechnic, UK.
[12]
Stern, R. J., Kroner, A., Bender, R., Reischmann, T. & Dawoud, A.S. (1994). Precambrian basement around Wadi Halfa, Sudan: A new perspective on th/e evolution of the East Saharan Craton.
[13]
Abdelsalam, M. G., Liegeois, J. & Stern, R. J., (2002). The Saharan Metacraton. J. African Earth Sciences, 34. P. 119-136.
[14]
Elsayed K. A. , El-Nadi A.H, Babiker I. S., (2014). Discovery of a New Style of Magnetite Mineralization, South of WadiHalfa Town, Northern Sudan. Open Transactions on Geosciences, Volume 1, Number 1, 7-12.
[15]
El-Nadi, A.H., (1989). Late Precambrian volcanism in NE Sudan and the evolution of the Nubian Shield. Journal of the African Earth Sciences, Pergamon Press, London; Vol. 9, No. 3/4, 467-480.
[16]
Abdel Rahman, E. M., (1983). The geology of the mafic-ultramafic masses and adjacent rocks south of Ingessana Igneous Complex, Blue Nile Province, E Sudan. MPhil thesis, Portsmouth Polytechnic, UK, 210pp.
[17]
Abdelsalam, M. G., Dawoud, A. S., (1991). The Kabus ophiolitic mélange, Sudan and its bearing on the W. boundary of the Nubian Shield. Journal Geological Society, London 148, 83-92.
[18]
Sultan M., Arvidson R.E., Sturchio N.C., Guinness E.A., (1987). Lithological mapping in arid egions with landsat thematic mapper data: Meatiq dome, Egypt. Geological Society of America Bulletin, V. 99, 748-762.
[19]
Abdelsalam M. G., Robert J. S., Berhane W.G., (2000). Mapping gossans in arid regions with Landsat TM and SIR-C images: the Beddaho Alteration Zone in northern Eritrea. Journal of African Earth Sciences, V. 30No. 4, 903-916.
[20]
Pournamdari M., Hashim M., Pour A.B., (2014). Application of ASTER and Landsat TM data for geological mapping of Esfandagheh ophiolite complex, southern Iran. Resource Geology, V. 64, Issue 3, 233-246.
[21]
El Janati M., Soulaimani A., Admou H., Youbi N., Hafid A., Hefferan K.P., (2014). Application of ASTER remote sensing data to geological ,aping of basement domains in arid regions: a case study from the Central Anti-Atlas, Iguerda inlier, Morocco. Arabian Journal of Geosciences, V. 7, Issue 6, 2407-2422.
[22]
Mwaniki M.W., Moeller M.S., Schellmann G., (2015). The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, V. XL-7/w3, 2015. 36th International Symposium on Remotes Sensing of Environment, 11-15 May 2015, Berlin, Germany.
