Early Cretaceous counterclockwise rotation of Northeast Africa within the equatorial zone: Paleomagnetic study on Mansouri ring complex, Southeastern Desert, Egypt | ||
| NRIAG Journal of Astronomy and Geophysics | ||
| Volume 4, Issue 1, June 2015, Pages 1-15 PDF (2.86 M) | ||
| DOI: 10.1016/j.nrjag.2015.01.001 | ||
| Author | ||
| A. Osman | ||
| Abstract | ||
| The Mansouri ring complex (132 Ma) is, paleomagnetically, studied to shed light on the paleo-tectonic position of Northeast Africa during the Early Cretaceous. Progressive thermal demagnetization of all samples verified a general bi-vectorial decay of the natural remanence. After the removal of the present-day field overprint, the decaying anchored component was either: Due to its steady stability, overwhelming existence in most sites, positive reversal test and its residence in fresh-samples’ magnetite, the first dual-polarity, shallow NW–SE component, was considered as the characteristic remanent magnetization [ChRM] representing the paleomagnetic field during cooling of the Mansouri ring complex. The mean paleomagnetic pole of the isolated ChRM was at 47°N/259°E, Dp/Dm = 3.4°/6.6°. This Hauterivian pole from Egypt shows reasonable consistency with its coeval poles rotated from the main tectonic units to Northeast Africa. It reveals that in Early Cretaceous: Comparing this Hauterivian pole to that of the Wadi Natash basalts [107 ± 4 Ma], which was at [55°N/250°E] during the Albian, the African Plate seems to have rotated counter-clockwise about 10° with Northeast Africa moving northwards [Cairo was moving from 1.5°S to 1.5°N] within the equatorial zone, during the Early Cretaceous. | ||
| Keywords | ||
| Paleomagnetism; Paleo-latitude; Mansouri ring complex; Africa; Early Cretaceous paleomagnetic pole | ||
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