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Petrology and the Western Rift of Central Africa

Published online by Cambridge University Press:  01 May 2009

A. W. Groves
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Extract

IN the course of several journeys between Masindi and Butiaba, and one from Butiaba to Hoima (via Waki Camp), specimens of the various gneisses were collected from roadside exposures. Thin sections of these were subsequently studied by the writer in England with the result that they were found to yield evidence of tectonic significance. In addition, the writer has, during the last three years, examined petrographically a large number of other rocks from those parts of Uganda bordering the Lake Albert Depression. In particular he has made a special study of the Charnockite Series, which are widely spread over the northern half of the Protectorate, with the result that it has been possible to observe the effects of the rift valley movements on these rocks in the regions adjacent to Lake Albert. It is hoped to publish a petrological and geochemical study of the Charnockite Series of Uganda in the near future. In the following pages it is proposed in Part I to present petrological evidence from the basement rocks of various districts in the hinterland of the Lake Albert scarps and then in Part II to point out the tectonic significance of this evidence in the light of the various theories of rift valley formation. In Part III the relation between the petrological characters of the volcanic rocks and the rift valley tectonics will be briefly reviewed. In the case of the basement rocks the remarks will be confined to the Lake Albert Depression, but in the case of the volcanic rocks the discussion will extend also to Lakes George and Edward and the Birunga volcanic field.

Type
Original Articles
Information
Geological Magazine , Volume 69 , Issue 11 , November 1932 , pp. 497 - 510
Copyright
Copyright © Cambridge University Press 1932

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References

BIBLIOGRAPHY

(1) Peacock, M. A., Journal of Geology, 1931, 54–67.CrossRefGoogle Scholar
(2) ÖDman, O. H., “ Preliminary Report on the Archaean Geology of Western Nzova Province, Kenya Colony,” Geol. Fören., Stockholm, 01.— 02., 1929.CrossRefGoogle Scholar
(3) Wayland, E. J., Compte Rendu, XV International Geological Congress, S. Africa, 1929, 323–53.Google Scholar
(4) Wayland, E. J., “ Some Account of the Geology of the Lake Albert Rift Valley,” Geographical Journal, 11., 1921.CrossRefGoogle Scholar
(5) Willis., Bailey, Living Africa, New York, 1930.Google Scholar
(6) Wayland, E. J., Memoir No. 1, Geol. Survey of Uganda, 1926.Google Scholar
(7) Hirst, T., Ann. Rep. Geol. Survey of Uganda, 1927.Google Scholar
(8) Tyrrell, G. W., The Principles of Petrology, London. 1926, 256 and 313.Google Scholar
(9) Holmes, A., and Harwood, H. F., Q.J.G.S., lxxxviii, 1932, 370–442.CrossRefGoogle Scholar
(10) Combe, A. D., Ann. Rept. Geol. Survey of Uganda, 1929, 16–18.Google Scholar
(11) Groves, A. W., Ann. Rept. Geol. Survey of Uganda, 1930, 12–16 and 41–2.Google Scholar
(12) Worthington, E. B., and Beadle, L. C., “ Thermoclines in Tropical Lakes,” Nature, 1930, cxxix, 55.Google Scholar
(13) Simmons, W. C., Geological Magazine, 1930, 491–9.CrossRefGoogle Scholar
(14) ÖDman, O. H., “ Volcanic Rocks of Mt. Elgon in British East Africa,” Geol. Fören., Stockholm, 11—12, 1930, 455–537.CrossRefGoogle Scholar
(15) Backlund, H. G., “ On the Mode of Intrusion of Deep-seated Alkaline Bodies,” Bull. Oeol. Instit, of Upsala, 1932, xxiv, 21–2.Google Scholar
(16) Simmons, W. C., Ann. Rept. Geol. Survey of Uganda, 1929, 36–7.Google Scholar
(17) Groves, A. W., Ann. Rept. Geol. Survey of Uganda, 1929, 27–8.Google Scholar