The dismembered fragments of the Alpine belt recovered around the Mediterranean basin are witnesses of the collisional events between Africa and Eurasia and of the opening of the western Mediterranean basins during the Cenozoic. In the eastern part of North Algeria, Cr-lherzolites outcrop in the Collo massif (c. 20km 2) within the metamorphic basement of Lesser Kabylia. The contact between these mantle rocks and the metasediments is outlined by HT cordierite-sillimanite-bearing kinzigites. Among the fourty-five peridotites studied, the large majority are spinelbearing lherzolites but few samples are harzburgites, dunites and also scarce garnet-bearing lherzolites. All samples show overall high serpentinization degree (LOI% up to 15). Olivine, spinel and pyroxene chemical composition displays weakly depleted geochemical character. WR and mineral trace elements patterns yield overall a typical abyssal-like signature with a steep LREE depletion (0.01