Antonio P. Y. J., Baratoux Lenka, Trindade R. I. F., Rousse Sonia, Ayite A., Lana C., Macouin M., Adu E. W. K., Sanchez C., Silva M. A. L., Firmin A. S., Dopico C. I. M., Proietti A., Amponsah P. O., Sakyi P. A. (2021). West Africa in Rodinia : high quality paleomagnetic pole from the similar to 860 Ma Manso dyke swarm (Ghana) [+ corrigendum, 2021, vol. 95, p. 10-13]. Gondwana Research, 94, 28-43 [+ corrigendum, 2021, vol. 95, p. 10-13]. ISSN 1342-937X.
Titre du document
West Africa in Rodinia : high quality paleomagnetic pole from the similar to 860 Ma Manso dyke swarm (Ghana) [+ corrigendum, 2021, vol. 95, p. 10-13]
Année de publication
2021
Auteurs
Antonio P. Y. J., Baratoux Lenka, Trindade R. I. F., Rousse Sonia, Ayite A., Lana C., Macouin M., Adu E. W. K., Sanchez C., Silva M. A. L., Firmin A. S., Dopico C. I. M., Proietti A., Amponsah P. O., Sakyi P. A.
Source
Gondwana Research, 2021,
94, 28-43 [+ corrigendum, 2021, vol. 95, p. 10-13] ISSN 1342-937X
The paleogeography of the Meso-Neoproterozoic Rodinia supercontinent remains debated partly because many stable cratons still lack reliable paleomagnetic data for this period. A new geochronological and paleomagnetic study was conducted on the NNW-trending Manso dyke swarm of southern West Africa (Ghana) to clarify the position of this unconstrained continent in Rodinia. Two U\\Pb apatite ages of 857.2 +/- 8.5 Ma and 855 +/- 16 Ma agree with one previous baddeleyite age, indicating a -860 Ma emplacement age for the Manso dykes. A characteristic remanent magnetization (ChRM) was isolated in stable single to pseudo-single domain (SD-PSD) magnetite. Well constrained site mean directions obtained for 13 dykes lead to a mean direction for the Manso dyke swarm of Dm = 181.9 degrees, Im = -77.2 degrees (N = 13, alpha 95 = 7.6 degrees, k = 30.6), yielding a paleomagnetic pole at 177.6 degrees E, 28.3 degrees S, (A95 = 12.7 degrees K = 11.6). Two directional clusters of opposite inclination passa reversal test (C-class) and the primary origin is supported by a positive baked contact test, satisfying all the seven R-criteria to provide the first West African Tonian key paleomagnetic pole. This key pole indicates a high latitude for the West Africa Craton during the emplacement of the-860 Manso dykes. A compilation of reliable paleomag-netic poles for West Africa, Baltica, Amazonia and Congo-S & atilde;o Francisco cratons suggests that these cratons were together between-1200 and 800 Ma in a long-lived WABAMGO configuration. We suggest that the collision of this block with Laurentia along the Grenvillian-Sunsas orogens closed the external Nuna Ocean and formed Rodinia by extroversion.
Plan de classement
Géologie et formations superficielles [064]
;
Géophysique interne [066]
Description Géographique
GHANA
Localisation
Fonds IRD [F B010081291]
Identifiant IRD
fdi:010081291
