Professeur et Directeur du Dpt.des Sciences de la Terre et de l’Atmosphère
The north eastern portion of the Archean Superior Province is becoming a very attractive region for diamond exploration in Canada. Development of an hypothesis concerning orogenic fronts (Archean, Paleoproterozoic or Grenvillian) as favorable structural controls for kimberlite emplacement, and their influence on reactivation of older faults are one of the main targets for diamond exploration. Discrimination of lineaments and alignment of alkaline intrusions (age vs. orientation) are crucial. Structural elements related to syn-Iapetus extension (early Cambrian) in the eastern Superior Province correspond with the main emplacement of the diamondiferous kimberlites. The similarities between the hypabyssal ultramafic lamprophyre Abloviak dykes (Paleoproterozoic Torngat orogen), the Otish Mountain kimberlite (550Ma) and the western Greenland “Nag” dykes suggest the possibility that a significant diamondiferous alkaline province is present in the northeastern North American craton.