It is generally believed that the Earth's magnetic field arises from dynamo action in the convecting outer core1-3. Thus the geomagnetic field, and especially its strength, can provide information about core processes. Recent determinations of the geomagnetic palaeointensity using Archaean and early Proterozoic samples from the Kaapvaal and Superior cratons are consistent with a sharp increase in the magnitude of the geomagnetic field between 2.7 and 2.1 Gyr. Analysis of published late Archaean and early Proterozoic apparent polar wander paths shows that an abrupt change in the rate and style of continental motion occurred at about 2.5-2.6 Gyr ago. If this change is also interpreted to be related to the growth of an inner core, then, an intriguing conjecture arises that the Archaean-Proterozoic transition is related to inner core nucleation. © 1987 Nature Publishing Group.
Paulesu, E., Mehler, J. (1998). Right on in sign language. NATURE, 329(6673), 233-234 [10.1038/32546].
Right on in sign language
Paulesu, E;
1998
Abstract
It is generally believed that the Earth's magnetic field arises from dynamo action in the convecting outer core1-3. Thus the geomagnetic field, and especially its strength, can provide information about core processes. Recent determinations of the geomagnetic palaeointensity using Archaean and early Proterozoic samples from the Kaapvaal and Superior cratons are consistent with a sharp increase in the magnitude of the geomagnetic field between 2.7 and 2.1 Gyr. Analysis of published late Archaean and early Proterozoic apparent polar wander paths shows that an abrupt change in the rate and style of continental motion occurred at about 2.5-2.6 Gyr ago. If this change is also interpreted to be related to the growth of an inner core, then, an intriguing conjecture arises that the Archaean-Proterozoic transition is related to inner core nucleation. © 1987 Nature Publishing Group.
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