The border of Cameroon and Chad is characterized by a Precambrian basement straddling the Touboro-Ba ? bokoum area; this basement is made up of gneiss, amphibolite and granitoids (granite, syenite, granodiorite). The studied rocks display high-K calk-alcalcaline to shoshonitic characteristic. Granitoids are metaluminous. Rocks under study derived from partial melts from metabasaltic to metatonalitic sources, and partial melts from metagreywackes. They shear the same origin as many granitoids describe westward in the Meiganga area and west Cameroon. This shows that the basement straddling the Touboro-Ba ? bokoum area belongs to the Adamawa-Yadé Domain of the Central African Fold Belt.
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