Bimodal volcanism Bimodal volcanism Bimodal volcanism is the eruption of both mafic and felsic lavas from a single volcanic centre with little or no lavas of intermediate composition. This type of volcanism is normally associated with areas of extensional tectonics, particularly rifts. Most occurrences of bimodal volcanism are associated with thinning of the crust and the presence of such rocks in metamorphic sequences has been used to provide evidence for past rifting events. Most examples come from areas of active continental rifting such as the Basin and Range Province. Bimodal volcanism has also been described from areas of transtension, the early phases
Lake Temagami a strong fault zone of sheared felsic to intermediate metavolcanic rocks that is approximately wide. This fault zone, known as the Northeast Arm Deformation Zone, and the associated metavolcanic rocks are associated with the Temagami Greenstone Belt, an Archean greenstone belt characterized by felsic-mafic volcanic rocks. Lake Temagami and its surrounding lakes provide endless opportunities for canoe camping. There are over 2,000 km of interconnecting canoe routes. The region contains some of the largest remaining stands of old growth red and white pine forests in Ontario. In 1834, the Hudson's Bay Company opened a fur trading post on the lake,