フォート・セルカーク火山域

The Fort Selkirk volcanic field near the junction of the Yukon and Pelly rivers in central Yukon is the northernmost Holocene volcanic field in Canada. It consists of a sequence of valley filling alkaline olivine basalt and basanitic lava flows succeeded by construction of three nephelinitic pyroclastic cones and lava flow aprons. The Ne Ch'e Ddhawa pyroclastic cone (Wootten's Cone) is composed primarily of hyaloclastite tuffs, breccias, and pillow breccias erupted subglacially during the late Pleistocene (Jackson, 1989). The youngest cone, Volcano Mountain, produced young nephelinitic lava flows that remain unvegetated and appear to be only a few hundred years old. However, dating of sediments in a lake impounded by the lava flows indicated that the youngest flows could not be younger than mid-Holocene and could be early Holocene or older (Jackson and Stevens, 1992).