Palaeomagnetism of the continental sector of the Cameroon Volcanic Line, West Africa |
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| Authors: | R U Ubangoh I G Pacca & J B Nyobe |
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| Institution: | Instituto Astronômico e Geofísico, Universidade de São Paulo, Av. Miguel Stefano, 4200, CEP 04301–970, São Paulo, SP, Brazil,;Ministry of Scientific and Technical Research, BP 4110, Yaounde, Cameroon |
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| Abstract: | Measurement of samples from 154 sites in the continental sector of the Cameroon Volcanic Line yielded six palaeomagnetic poles, at 243.6°E, 84.6°N, α 95 = 6.8°; 224.3°E, 81.2°N, α 95 = 8.4°; 176.1°E, 82.0°N, α 95 = 8.5°; 164.3°E, 86.4°N, α 95 = 3.4°; 169.4°E, 82.6°N, α 95 = 4.6° and 174.7°E, 72.8°N, α 95 = 9.5°, belonging to rocks which have been dated by the K–Ar method at 0.4–0.9 Ma, 2.6 Ma, 6.5–11 Ma, 12–17 Ma, 20–24 Ma and 28–31 Ma, respectively. The results are in general agreement with other palaeomagnetic poles from Oligocene to Recent formations in Africa.
The first three poles for rocks formed between 0.4 and 11 Ma are not significantly different from the present geographical pole. Together with other African poles for the same period, this suggests that the African continent has moved very little relative to the pole since 11 Ma. The other three poles for rocks dated between 12 and 31 Ma are significantly different from the present geographical pole, showing a 5° polar deviation from the present pole in the Miocene and 13° in the Middle Oligocene. |
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| Keywords: | Cameroon palaeomagnetism |
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