CONSTRAINTS ON THE MOTIONS OF SOUTH AMERICAN AND AFRICAN SHIELDS DURING THE PROTEROZOIC: I. 40Ar/39Ar AND PALEOMAGNETIC CORRELATIONS BETWEEN VENEZUELA AND LIBERIA.

Publication Year
1984

Type

Journal Article
Abstract
The Encrucijada pluton of Venezuela and amphibolites near Harper, Liberia, are located on opposite sides of the Liberian Pan-African mobile belt, when South America is restored in a fit described in the literature with respect to Africa. Both units yield stable, bipolar, high-temperature magnetizations that appear to be indistinguishable in age at 1. 9 to 2. 0 Ga. With South America in this reconstruction, the corresponding paleomagnetic poles suggest that 1000 km of right-lateral strike-slip motion has occured between the West African and Guayana Shields. The Encrucijada and Harper poles are distinct from the 1. 9- to 2. 0-Ga paleomagnetic poles from the Kalahari Shield and suggest that relative motion has occurred between the Kalahari Shield and the West African and Guayana Shields since that time. Refs.
Journal
Bulletin of the Geological Society of America
Volume
95
Pages
1045-1054