Abstract

Peridotite xenoliths of wehrlite composition, scarcely known in Adamawa plateau, Cameroon, were sampled by Mio-Pliocene basanites from Hosséré Do Guessa volcano. Their origins are discussed and elucidated trough petrography and mineral chemistry. Studied wehrlites exhibit poikilitic or protogranular textures and are composed of four main mantle phases (high Mg-olivine, augite, enstatite and Al-spinel). Petrographic and microprobe (Camebax SX100) chemical data (Fo90.8-91.4 olivine, Wo39.4-42.0 augite, En90.5-91.1 enstatite and Al-spinel) suggest a mantle origin for the Hosséré Do Guessa wehrlites. Hence, these rocks could not be considered cumulate. They have been equilibrated between 1,140 and 1,220°C, at pressures of 1.5–2.0 GPa, at 50–66 km deep, below the crust-mantle boundary. Wehrlites might result in reactions with carbonate/carbonatite melt, accompanying CO2 degassing and metasomatism by fluid phases. They suffered transpressional tectonics, during movement at Tertiary times of Pan-African strike-slip-faults, after solid-state tectonic relaxation.

Details

Title
Wehrlite xenoliths and petrogenetic implications, Hosséré Do Guessa volcano, Adamawa plateau, Cameroon
Author
Nkouandou, Oumarou Faarouk 1 ; Jacques-Marie Bardintzeff 2 ; Zénab Nouraan Njankouo Ndassa 3 ; Mefire, Aminatou Fagny 3 ; Haman, Adama 3 

 Department of Earth Sciences, Faculty of Sciences, University of Ngaoundéré, P.O. Box. 454, Ngaoundéré, Cameroon; Department of Mineral Engineering, Chemical Engineering and Minerals Industry School, University of Ngaoundéré, P.O. Box. 454, Ngaoundéré, Cameroon 
 Univ Paris-Saclay, Department of Sciences de la Terre, Volcanologie-Planétologie, UMR CNRS 8148 GEOPS, bât. 504, F-91405 Orsay, France 
 Department of Earth Sciences, Faculty of Sciences, University of Ngaoundéré, P.O. Box. 454, Ngaoundéré, Cameroon 
Pages
1075-1091
Publication year
2022
Publication date
2022
Publisher
De Gruyter Brill Sp. z o.o., Paradigm Publishing Services
e-ISSN
23915447
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2725156104
Copyright
© 2022. This work is published under http://creativecommons.org/licenses/by/4.0 (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.