Geoelectrical deep soundings in Southern Africa using the Cabora Bassa power line

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E.K. Blohm
P. Worzyk
H. Scriba


Geoelectrical deep soundings with electrode spacings between 30 and 1250 km have been carried out from 1973 to 1975 in southern Africa using the Cabora Bassa power line. At several sounding stations (Schlumberger and bipole-dipole arrays) the electric potential differences have been recorded in different directions. For short current-electrode spacings (< 200 km) the direction of the electric field is nearly perpendicular to the direction between the current electrodes whereas it becomes more or less parallel for large electrode spacings (> 400 km). A possible cause for this rotation of the field may be a dyke system observed in the granitic crust.

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Blohm, E., Worzyk, P., & Scriba, H. (1977). Geoelectrical deep soundings in Southern Africa using the Cabora Bassa power line. Journal of Geophysics, 43(1), 665-679. Retrieved from
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Adam, A. (Ed.) (1976) Geoelectric and geothermal studies (East-Central Europe, Soviet Asia). KAPG geophysical monograph, Budapest

Bloch, S., Hales A.L., Landisman, M. (1969) Velocities in the crust and upper mantle of southern Africa from multimode surface wave dispersion. Bull. Seism. Soc. Am. 59:1599-1629

Blohm, E.-K. (1972) Die Methode der geoelektrischen Tiefensondierungen mit groBen Elektrodenentfernungen. Doctoral thesis, Technical University Clausthal, 71 pp.

Blohm, E.-K., Plathe, H. (1970) Geoelectrical deep sounding in the Rhinegraben. In: Illies, H. (Ed.) Graben problems (Intern. Upper Mantle Proj. Scien. Rep. 27), pp. 239-242, Stuttgart

Brace, W.F. (1971) Resistivity of saturated crustal rocks to 40 km based on Laboratory results. In: Heacock, J.G. (Ed.) The structure and physical properties of the Earth's crust, AGU Geophys.
Monograph, Vol. 14, pp. 243-255

De Beer, J.H., Gough D.I., Van Zijl J.S.V. (1975) An electrical conductivity anomaly and rifting in southern Africa. Nature 255:678-680

Dennert, U. (1977) Programm zur direkten Interpretation geoelektrischer Sondierungskurven fur horizontal geschichteten Untergrund. Archiv NUB

Fairhead, J.D., Reeves, C.V. (1976) Teleseismic delay time, seismicity and inferred thickness of the African Lithosphere. Earth Planet. Sci. Letters, submitted for publication

Homilius, J., Blohm, E.-K. (1973) Modell zur Interpretation der geoelektrischen Tiefensondierung im Rheingraben 1967. J. Geophys. 39:441-459

Keller, G.V. (1971) Electrical studies of the crust and the upper mantle. In: Heacock, J.G. (Ed.) The structure and physical properties of the Earth's crust, AGU geophysical monograph no. 14, Washington

Reeves, C.V., Hutchins, D.G. (1975) Crustal structures in central southern Africa. Nature 254:408-410

Schmucker, U. (1974) Erdmagnetische Tiefensondierungen mit langperiodischen Variationen. Protokoll uber das Kolloquium "Erdmagnetische Tiefensondierung" in Grafrath (FRG)

Van Zijl, J.S.V. (1969) A deep Schlumberger sounding to investigate the electrical structure of the crust and upper mantle in South Africa. Geophysics 34:450-462

Van Zijl, J.S.V. (1976) Electrical Studies of the deep crust in various tectonic provinces of Southern Africa. Paper, read on ONR Symposium on the Nature and Physical Properties of the Earth's Crust, Vail, Colorado, August

Van Zijl, J.S.V., Hugo, P.L.V., De Bellocq, J.H. (1970) Ultra deep Schlumberger sounding and crustal conductivity structure in South Africa. Geophys. Prospecting 18:615-634

Van Zijl, J.S.V., Joubert, S.J. (1975) A crustal geoelectrical model for South African Precambrian granitic terrains based on deep Schlumberger soundings. Geophysics 40:657-063

Zohdy, A.A.R. (1970) Geometric factors of bipole-dipole arrays. U.S. Departement of Geological Survey Bull., 1313-B, 26 pp.