Geomagnetic Reversals during the Phanerozoic

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Science  09 Apr 1971:
Vol. 172, Issue 3979, pp. 157-159
DOI: 10.1126/science.172.3979.157


An antalysis of worldwide paleomagnetic measurements suggests a periodicity of 350 x 106 years in the polarity of the geomagnetic field. During the Mesozoic it is predominantly normal, whereas during the Upper Paleozoic it is predominantly reversed. Although geomagnetic reversals occur at different rates throughout the Phanerozoic, there appeaars to be no clear correlation between biological evolutionary rates and reversal frequency.

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