Numerous ultramafic xenoliths occur within the Aïn-Temouchent volcanic complex (Northwestern Oranie, Algeria). Most of them are type I mantle tectonites (lherzolites and harzburgites) and composite xenoliths (harzburgite/clinoproxenite) are rare. Only a few samples of spinel lherzolites display relatively fertile compositions when the major part of type I xenoliths have refractory major element compositions but enriched LREE contents showing that they have been affected by mantle metasomatism. The composite xenoliths are witnesses of reactions of alkaline magmas with the upper mantle. An asthenospheric rising, in relation with the large strike slip fault affecting the North African plate margin at Trias time is proposed as a possible geodynamical setting. To cite this article: M. Zerka et al., C.R. Geoscience 334 (2002) 387-394.
|Translated title of the contribution||Ultramafic xenoliths from Quaternary alkali volcanism from Oranie (Tell, western Algeria): Witnesses of a sheared and enriched lithosphere|
|Number of pages||8|
|Journal||Comptes Rendus Geoscience|
|Publication status||Published - 2002|
- Lithospheric thinning
- Mantle metasomatism
- Upper mantle