THE AGES OF CARBONATITE COMPLEXES IN EASTERN CANADA

摘要: There are four chronological groups of carbonatite complexes in Ontario and Quebec. These about 125 m.y., 565 m.y., 1075 m.y., 1700 m.y., with a possible fifth at 1560 m.y. The recently proposed St. Lawrence Rift System is not considered to be very likely control emplacement unless it includes widespread system branch faults. coincidence the "Kapuskasing High" striking probably puts minimum age 1750 m.y, on feature. Niobium found carbonatites each group.