gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1962.033.256.07 The Age of Fergusonite from the Jos Area, Northern Nigeria1 Darnley A. G.M.A., Ph.D., A.M.I.M.M., F.G.S. Atomic Energy Division, Geological Survey of Great Britain Smith G. H. Chandler T. R. D. National Chemical Laboratory, Teddington, Middlesex Dance D. F. Atomic Energy Research Establishment, Harwell, Berkshire.

A preliminary account of these results was issued in September 1959 on a limited circulation by the Atomic Energy Division, Geological Survey of Great Britain, as Age Determination Report No. 10.

 3 1962 33 256 48 51 Copyright © 1962, The Mineralogical Society 1962 Summary

Two fergusonite concentrates from different localities in the Jos area of Northern Nigeria have been analysed by the complete lead method and are accepted as having a mean age of 159±25 m.y.