Abstract
The island of Kod Ali is a small diatreme cone lying close to the Ethiopian coast at latitude 13° 57′ N, longitude 41° 49′ E. This volcanic structure, produced by geologically Recent volcanic activity, consists, almost entirely, of pyroclastic debris. Evidence of a liquid phase is confined to the thin veneers of markedly alkalic olivine basalt which coat many of the abundant gabbroic, pyroxenitic and lherzolitic fragments found on the island. As silicic inclusions are completely absent and as the alkalic liquid phase and the “tholeiitic” inclusions are seemingly genetically unrelated, it is proposed that the latter might have been derived from a tholeiitic plutonic layered sequence that underlies the tholeiitic basalts of an “oceanic” Red Sea floor.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Barberi, F., Borsi, S., Ferrara, G., Marinelli, G., Varet, J.: Relations between tectonics and magmatology in the northern Danakil Depression (Ethiopia). Phil. Trans. Roy. Soc. London, Ser. A 267, 293–312 (1970).
Binns, R.A., Duggan, M.B., Wilkinson, J.G.F.: High pressure megacrysts in alkaline lavas from north eastern New South Wales. Am. J. Sci. 269, 132–168 (1970).
Cann, J.R.: (a) Petrology of basalts dredged from the Gulf of Aden. Deep-Sea Res. 17, 477–482 (1970).
—: (b) New model for the structure of the oceanic crust. Nature 226, 928–930 (1970).
Chase, R.L.: Basalt from the axial trough of the Red Sea. In: Hot brines and recent heavy metal deposits in the Red Sea (Degens, E.T., and Ross, D.A., eds.). New York 1969.
Davies, D., Tramontini, C.: The deep structure of the Red Sea. Phil. Trans. Roy. Soc. London, Ser. A 267, 181–190 (1970).
Forbes, R.B., Kuno, H.: Peridotite inclusions and basaltic host rocks. In: Ultramafic and related rocks (ed. by P. J. Wyllie), p. 328–337. New York: Wiley 1967.
Gass, I. G.: Proposals concerning the variation of volcanic products and processes within the oceanic environment. Phil. Trans. Roy. Soc. London, Ser. A (in press).
—, Mallick, D.I.J., Cox, K.G.: The Royal Society volcanological expedition to the South Arabian Federation and the Red Sea. Nature, 205, 952 (1965).
- - - The volcanic islands of the Red Sea. (In preparation.)
Hotz, P.E., Jackson, E.D.: X-ray determinative curve for olivines of composition Fo80–95 from stratiform and Alpine-type peridotites. U.S. Geol. Surv. Profess. Papers 450-E, 101–102 (1963).
Hutchison, R., Paul, D. K., Harris, P. G.: Chemical Composition of the upper mantle. Mineral. Mag. 37, 726–729 (1970).
McBirney, A.R., Gass, I.G.: Relations of oceanic volcanic rocks to mid-oceanic rises and heat flow. Earth Planet, Sci. Lett. 2, 265–276 (1967).
O'Hara, M. J.: Mineral parageneses in ultrabasic rocks. In: Ultramafic and related rocks, (ed. by P. J. Wylie) p. 393–403. New York: Wiley 1967.
Oxburgh, E.R.: Plate tectonics. In: Understanding the earth (Gass, I.G., Smith, P.J., and Wilson, R.C.L., eds.). Horsham, England: Artemis Press 1970.
Strong, D.: The petrology of the Grande Comore lavas, Comores Islands, Indian Ocean. Unpubl. Ph. D. thesis, University of Edinburgh (1970).
Varne, R.: Hornblende lherzolite and the upper mantle. Contr. Mineral. and Petrol. 27, 45–51 (1970).
Wager, L.R., Brown, G.M.: Layered igneous rocks. Edinburgh: Oliver & Boyd 1968.
White, R.W.: Ultramafic inclusions in basaltic rocks from Hawaii. Contr. Mineral. and Petrol. 12, 245–314 (1966).
Wright, J. B.: (a) Oligoclase-andesine phenocrysts and related inclusions in basalts from part of the Nigerian Cenozoic province. Mineral. Mag. 36, 1024–1031 (1968).
—: (b) Deep crustal origin for oligoclase and andesine phenocrysts in basalt form Gombe, Nigeria. Nature 218, 262–263 (1968).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hutchison, R., Gass, I.G. Mafic and ultramafic inclusions associated with undersaturated basalt on Kod Ali Island, Southern Red Sea. Contr. Mineral. and Petrol. 31, 94–101 (1971). https://doi.org/10.1007/BF00373452
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00373452