Stratovolcano Stratovolcano A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava, tephra, pumice and ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and periodic intervals of explosive eruptions and effusive eruptions, although some have collapsed summit craters called calderas. The lava flowing from stratovolcanoes typically cools and hardens before spreading far due to high viscosity. The magma forming this lava is often felsic, having high-to-intermediate levels of silica (as in rhyolite, dacite, or andesite), with lesser amounts of less-viscous mafic magma. Extensive
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,