Shield making in Western Kenya

The Precambrian Kisii Series in Western Kenya is unmetamorphosed and contains andesites, rhyolites, quartzites and basalts. The basalts, for which a minimum K-Ar age of 930 My is cited, were sampled at 15 sites, and after A.F. treatment nine sites yielded a stable palaeomagnetic direction which is b...

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Bibliographic Details
Main Author: Onyango, Walter H
Format: Article in Journal/Newspaper
Language:English
Published: 1971
Subjects:
Online Access:http://hdl.handle.net/11295/15867
Description
Summary:The Precambrian Kisii Series in Western Kenya is unmetamorphosed and contains andesites, rhyolites, quartzites and basalts. The basalts, for which a minimum K-Ar age of 930 My is cited, were sampled at 15 sites, and after A.F. treatment nine sites yielded a stable palaeomagnetic direction which is believed to be primary. The mean direction (N= 9) after tilt correction is D= 99°, I=−59°, α= 10°, and the corresponding palaeomagnetic south pole is at 6° N, 12° W with A95= 14°. This pole lies close to several other poles for Africa but it is of a very different age and it cannot be correlated with them. Instead it is suggested that the Kisii pole must form part of a previously undefined polar wander path for the Late Precambrian of Africa proposed in an accompanying paper by Brock and Piper.