Pre-Leonian relics (3.15 Ga) involved in the juvenile Birimian terrains (2.1 Ga) of Ivory Coast, West African craton

Relics of Archean gneiss are found within the juvenile Birimian magmatic domain of the Ivory Coast (San Pedro area, Sasca zone). The tonalite gneisses studied here yield single-grain zircon ages (up to 3141 = 2 Ma), that are significantly older than the emplacement of grey gneiss precursors (3048 = 8 Ma) within the Archean Domain of Man Rise, which points to a pre-Leonian crustal history. The presence of Archean relics, inherited zircons and negative ξNd values at 2.1 Ga in the Birimian domain indicate some interaction between the Archean crust and the newly formed mantle-derived magmas. Consequently, some geographical link may have existed between the Archean basement terrains and the juvenile magmatic belt that existed in the Birimian Domain 2.2-2.1 Ga ago. (authors)