Petrographic, Radiometric and Paleomagnetic Studies for Some Alkaline Rocks, South Nusab El Balgum Mass Complex, South Western Desert, Egypt


Nusab El Balgum mass complex represents one of the alkaline igneous activities in the south Western Desert of Egypt. Petrographic investigations defined some different rock types in south of the complex represented by alkaline volcanics (pyroclastics [rhyolitic crystal tuffs], spherulitic rhyolites, alkaline rhyolite dykes), sub-volcanic peralkaline granites and structurally controlled mylonitic volcanoclastics. These rocks recorded significant concentrations in terms of the two radioactive elements Th and eU, which displayed considerable spatial variations, especially within the peralkaline granites. The abundance of Th and eU is mainly related to favorable combination of structural and pos-magmatic hydrothermal conditions. Paleomagnetic results give well-defined stable remanent magnetization directions of reliable VGP positions, which are presented and discussed in the context of the African APWP. Rock types, magnetization directions and VGP positions with the corresponding ages are as follows: 1) Rhyolitic crystal tuffs; D/I = 340.0°/—19.4°, α95 = 6.8°; VGP Lat./Long. = 51.4°N/240.5°E, A95 = 5.9° (Late Triassic). 2) Spherulitic rhyolites; D/I = 346.7°/—6.6°, α95 = 3.5°; VGP Lat./Long. = 60.4°N/237.0°E, A95 = 3.0° (Late Triassic/Early Jurassic). 3) Alkaline rhyolite dykes; D/I = 341.3°/16.7°, α95 = 5.4°; VGP Lat./Long. = 67.0°N/262.8°E, A95 = 4.2


Radiometric; Paleomagnetic; Alkaline Volcanics; Peralkaline Granite; Amorphous Secondary Uranium; Thorium

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R. A. M. Elsayed, H. M. Assran and S. A. Abu Elatta, "Petrographic, Radiometric and Paleomagnetic Studies for Some Alkaline Rocks, South Nusab El Balgum Mass Complex, South Western Desert, Egypt," Geomaterials, Vol. 4 No. 1, 2014, pp. 27-46. doi: 10.4236/gm.2014.41004.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] J. T. Nash, “Volcanogenic Uranium Deposits: Geology, Geochemical Processes and Criteria for Resource Assessment,” US Geological Survey, Open-File Report 2010-1001, 2010, 110 p.
[2] International Atomic Energy Agency (IAEA), “World Distribution of Uranium Deposits (UDEPO) with Uranium Deposit Classification,” Vienna, Austria, International Atomic Energy Agency, IAEA-TECDOC-1629, 2009, 117 p.
[3] M. Cuney and K. Kyser, “Recent and Not-So-Recent Developments in Uranium Deposits and Implications for Exploration,” Mineralogical Association of Canada, Short Course Series, Vol. 39, 2009, 257 p.
[4] P. De Gruyter and T. A. Vogel, “A Model for the Origin of the Alkaline Complexes of Egypt,” Nature, Vol. 291, No. 5816, 1981, pp. 571-574.
[5] M. Y. Meneisy, “Volcanicity,” In: R. Said, Ed., The Geology of Egypt, A. A. Balkema, Rotterdam, 1990, pp. 157-174.
[6] R. Black, J. Lameyer and B. Bonin, “The Structural Setting of Alkaline Complexes,” Journal of African Earth Sciences, Vol. 3, No. 1-2, 1985, pp. 5-16.
[7] P. Bowden, “The Geochemistry and Mineralization of Alkaline Ring Complexes in Africa (a Review),” Journal of African Earth Sciences, Vol. 3, No. 1-2, 1985, pp. 17- 39.
[8] N. L. El Agami and H. M. Abdalla, “Geochemistry of Garra El Hamra Y, Th, REE-Mineralized Peralkaline Granite-Syenite Complex, Southwestern Desert, Egypt,” A Metallogenetic Constraint Egypt Min, Vol. 15, 2006, pp. 43-77.
[9] S. A. Abu Elatta, H. M. Assran and A. A. Ahmed, “Preliminary Study on HFSE Mineralization in the Peralkaline Granites of Nusab El Balgum Area, South Western Desert, Egypt,” Geomaterials, 2013, Vol. 3, No. 3, pp. 90-101.
[10] B. Issawi, “The Geology of Kurkur-Dungul Area,” Egyptian Geological Survey, Paper 46, 1969, 102 p.
[11] H. Schandelmeier, A. Rich and G. Franz, “Outline of the Geology of Magmatic Units Between Gabal Uweinat and Bir Safsaf (SW Egypt/NW Sudan),” Journal of African Earth Sciences, Vol. 1, No. 3-4, 1983, pp. 275-283.
[12] H. M. Assran, A. A. Hamed, A. A. Arbab, A. A. Ahmed, N. M. Moghazy and S. A. Abu Elatta, “Reconnaissance Radiometric Survey in Bir Safsaf-Nusab El Balgum Area, South Western Desert, Egypt,” Nuclear Materials Authority of Egypt, Internal Report, 2012.
[13] L. T. D. Conoco-Corporation, “Geological Map of South Western Desert Egypt, Scale 1:500.000. Sheet No. NF 53 NV, Gilf Kabeir Plateau,” Egyptian General Petroleum Corporation, Cairo, 1987.
[14] D. Marsal, “Statistics for Geoscientists,” University of Stuttgart, Stuttgart, 1987.
[15] S. R. Taylor, “The Application of Trace Element Data to Problem in Petrology,” Physics and Chemistry of the Earth, Progress Series, Vol. 6, 1965, pp. 133-213.
[16] J. J. W. Rogers, M. A. Ghuma, R. M. Nagy, J. K. Greenberg and P. D. Fullagar, “Plutonism in Pan-African Belts and Geologic Evolution of Northeastern Africa,” Earth and Planetary Science Letters, Vol. 39, No. 1, 1978, pp. 109-117.
[17] H. H. Bostock, “A General Diaper of Batholithic Dimensions at the West Margin of the Churchill Province,” Current Research, Part B, Geological Survey of Canada, Paper 81, 1981, pp. 73-82.
[18] B. W. Charbonneau, “Radiometric Study of Three Radioactive Granites in the Canada Shield: Elliot Lake, Ontario; Fort Smith; and Fury and Hecla, N.W.T,” In: Y. T. Maurice, Ed., Uranium in Granites, Geological Survey of Canada, 1982, pp. 91-99.
[19] W. Yanting, F. Mingyue and S. Zhuyong, “Uranium Geochemistry of the Granites in Eastern Guangdon Provence,” International Symposium on the Geology of Granites and Their Metallogenetic Relations, Nanjing University, Nanjing, 1982, pp. 637-649.
[20] D. T. Tarling, “Palaeomagnetism: Principles and Applications in Geology, Geophysics and Archaeology,” Chapman and Hall, London, New York, 1983, 379 p.
[21] D. J. Dunlop, “Magnetic Mineralogy of Heated and Unheated Red Sediments by Coercivity Spectrum Analysis,” Geophysical Journal of the Royal Astronomical Society, Vol. 27, No. 1, 1972, pp. 37-55.
[22] D. J. Dunlop, “Magnetic Properties of Fine-Particle Heamatite,” Annals of Geophysics, Vol. 27, 1971, pp. 269-293.
[23] D. W. Collinson, “Methods in Rock Magnetism and Palaeomagnetism,” Techniques and Instrumentation, Chapman & Hall, London, 1983, 503 p.
[24] W. O’Reilly, “Rock and Mineral Magnetism,” Blackie, Chapman & Hall, New York, 1984, 220 p.
[25] J. D. A. Zijderveld, “A. C. Demagnetization of Rocks: Analysis of Results,” In: D. W. Collinson, K. M. Creer and S. K. Runcorn, Eds., Methods in Palaeomagnetism, Elsevier, Amsterdam, New York, 1967, pp. 254-286.
[26] J. L. Kirschvink, “The Least-Squares Line and Plane and the Analysis of Palaeomagnetic Data,” Geophysical Journal International, Vol. 62, No. 3, 1980, pp. 699-718.
[27] R. A. Fisher, “Dispersion on a Sphere,” Proceedings of the Royal Society, Vol. 217, No. 1130, 1953, pp. 295-305.
[28] R. Van der Voo, “The Reliability of Paleomagnetic Data,” Tectonophysics, Vol. 184, No. 1, 1990, pp. 1-9.
[29] T. H. Torsvik, R. Van der Voo, U. Preeden, C. M. Niocaill, B. Steinberger, P. V. Doubrovine, D. J. J. van Hinsbergen, M. Domeier, C. Gaina, E. Tohver, J. G. Meert, P. J. A. McCausland and L. R. M. Cocks, “Phanerozoic Polar Wander, Palaeogeography and Dynamics,” Earth-Science Reviews, Vol. 114, No. 1-3, 2012, pp. 325-368.
[30] P. L. McFadden and M. W. McElhinny, “Classification of the Reversals Test in Palaeomagnetism,” Geophysical Journal International, Vol. 103, No. 3, 1990, pp. 725-729.
[31] H. Schandelmeier, E. Klitzsch, F. Hendriks and P. Wycisk, “Structural Development of North-East Africa since Precambrian Time,” Berliner Geowissenschaft Abhandlung, Vol. 75, 1987, pp. 5-24.
[32] J. Klerkx and C. C. Rundle, “Preliminary K/Ar Ages of Different Igneous Rock Formations from Jebel Uweinat Region (S.E. Libya),” Rapp. Ann. (1975), Mus. Roy. Afrique Centrale, Dep. Geol. Min., 1976, pp. 105-111.
[33] G. Franz, H. Puchelt and P. Pasteels, “Petrology, Geo-Chemistry and Age Relation of Triassic and Tertiary Volcanic Rocks from SW-Egypt and NW-Sudan,” Journal of African Earth Sciences, Vol. 6, No. 3, 1987, pp. 335-352.
[34] H. Schandelmeier and F. Darbyshire, “Metamorphic and Magmatic Events in the Uweinat Bir Safsaf Uplift (Western Desert, Egypt),” Geologische Rundschau, Vol. 73, No. 2, 1984, pp. 819-831.
[35] R. Y. Guiraud, J. Bellion, Benkhelil and C. Moreeau, “Post-Hercynian Tectonics in Northern and Western Afri- ca,” African Geology Review, Geological Journal, Vol. 22, Suppl. 2, 1987, pp. 433-466.
[36] M. H. L. Deenen, M. Ruhl, N. R. Bonis, W. Krijgsman, W. Kuerschner, M. Reitsma and M. J. van Bergen, “A New Chronology for the End-Triassic Mass Extinction,” Earth and Planetary Science Letters, Vol. 291, No. 1-4, 2010, pp. 113-125.
[37] C. Labails, J. L. Olivet, D. Aslanian and W. R. Roest, “An Alternative Early Opening Scenario for the Central Atlantic Ocean,” Earth and Planetary Science Letters, Vol. 297, No. 3-4, 2010, pp. 355-368.
[38] A. Hashad and M. W. El Reedy, “Geochronology of the Anorogenic Alkaline Rocks, South Eastern Desert, Egypt,” Ann. Geol. Egypt, Vol. 9, 1979, pp. 81-101.
[39] M. E. H. Abdelrahman, “Geochemical and Mineralogical studies of Rare Metal Mineralization in Garra El Hamra Granite Syenite Complex and the Surrounding Environ, South Western Desert, Egypt”, M.Sc. Thesis, Mansoura University, Damietta, 2009, 155 p.
[40] C. M. C. Serencsits, M. F. El Ramly, K. A. Foland and A. A. Hussein, “Alkaline Ring Complexes in Egypt, There Ages and Relationship to Tectonic Development of Red Sea,” Ann. Geol. Surv. Egypt, Vol. 9, 1979, pp. 102-116.
[41] T. H. Torsvik, R. D. Tucker, L. D. Ashwal, E. A. Eide, N. A. Rakotosolofo and M. J. de Wit, “Late Cretaceous Magmatism in Madagascar: Palaeomagnetic Evidence for a Stationary Marion Hotspot,” Earth and Planetary Science Letters, Vol. 164, No. 1-2,1998, pp. 221-232.
[42] S. El Gaby, F. K. List and R. Tehrani, “Geology, Evolution and Metallogenesis of the Pan-African Belt in Egypt,” In: S. El Gaby and R. O. Greiling, Eds., The Pan-African Belt of Northeast Africa and Adjacent Areas, Friedrich Vieweg, Berlin,1988, pp. 17-68.
[43] G. Muttoni, E. Erba, D. V. Kent and V. Bachtadse, “Mesozoic Alpine Facies Deposition As a Result of Past Latitudinal Plate Motion,” Nature, Vol. 434, No. 7029, 2005, pp. 59-63.
[44] M. J. M. Meijers, C. G. Langereis, D. J. J. van Hinsbergen, N. Kaymakci, R. A. Stephenson and D. Altiner, “Jurassic-Cretaceous Low Paleolatitudes From the Circum-Black Sea Region (Crimea and Pontides) Due to True Polar Wander,” Earth and Planetary Science Letters, Vol. 296, No. 3-4, 2010, pp. 210-226.

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