Un massif granitique de l'Ahaggar a mode de gisement hybride; le Tihoiiarene

Abstract The Tihoiiarene granite massif is a crescent-shaped body on the northeastern margin of a large syntectonic massif of porphyritic granite in the Ahaggar mountains, Algeria. The contact of the Tihoiiarene massif with epimetamorphic Precambrian formations is typically intrusive, but its contact with the porphyritic granite is blurred in places, clear-cut in others, thus providing no evidence of chronologic relationships. Similar cases are known elsewhere; possibly there is a direct relation between the migmatitic (or anatectic) and intrusive granites, the latter grading into subvolcanic plutons.