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Composite phonolite tholoids in the Cenozoic volcanic province of Nigeria

Published online by Cambridge University Press:  01 May 2009

J. B. Wright  and
Patricia McCurry
J. B. Wright
Affiliation:
Department of Earth Sciences, The Open University, Walton, Buckinghamshire
Patricia McCurry
Affiliation:
Department of Earth Sciences, The Open University, Walton, Buckinghamshire
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Summary

Small trachyte and phonolite bodies are shown as eroded plugs on published geological maps of part of north-eastern Nigeria. Field relationships at two such ‘plugs’ strongly suggest them to be extrusive in origin, formed of an earlier tholoid-building phase, followed by extrusion of a spine (plug dome) of very viscous lava, now forming the central peak at each locality. Petrographic data show that the tholoid and spine-forming lavas are phonolites of contrasted composition. Eruption of salic lavas from scattered centres appears to have occurred intermittently between mid-Tertiary and Pleistocene times.

Type
Articles
Information
Geological Magazine , Volume 107 , Issue 4 , July 1970 , pp. 357 - 360
Copyright
Copyright © Cambridge University Press 1970

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References

REFERENCES

Carter, J. D., Barber, W., & Tait, E. A., 1963. The geology of parts of Adamawa, Bauchi and Bornu Provinces in north-eastern Nigeria. Bull. geol. Surv. Nigeria, No. 30.Google Scholar
Cotton, C. A., 1952. Volcanoes as landscape forms (2nd ed.) Whitcombe and Tombs, New Zealand.Google Scholar
Cratchley, C. R., & Jones, G. P., 1965. An interpretation of the geology and gravity anomalies of the Benue valley, Nigeria. Overseas geol. Surv., Geophys. Pap. No. 1.Google Scholar
MacKay, R. A., Greenwood, R., & Rockingham, J. E., 1949. The geology of the Plateau tinfields: Resurvey 1945–1948. Bull. geol. Surv. Nigeria, No. 19.Google Scholar
Wright, J. B., 1968 a. Oligoclase-andesine phenocrysts and related inclusions in basalts from part of the Nigerian Cenozoic province. Miner. Mag., 36, 1024–31.Google Scholar
Wright, J. B., 1968 b. South Atlantic continental drift and the Benue trough. Tectonophysics, 6, 301–10.CrossRefGoogle Scholar