Anahim Hotspot - Geological History - Nazko Cone Eruptive Period

Nazko Cone Eruptive Period

Throughout the Holocene epoch, the Anahim hotspot has energized numerous volcanoes. This volcanic activity has produced numerous Hawaiian eruptions, which created lava fountains, small cinder cones and lava flows. The youngest expression of the Anahim hotspot is Nazko Cone, which formed about 340,000 years ago. The most recent eruptive activity at Nazko Cone occurred about 7,200 years ago. This is very recent in geological terms, suggesting that the volcano may yet have some ongoing volcanic activity. The Rainbow Range is the largest Anahim volcano, although Nazko Cone is now the site of the most intense volcanic activity, located directly on top of the Anahim hotspot at Coordinates: 52°54′0″N 123°44′0″W / 52.9°N 123.733333°W / 52.9; -123.733333. Its last eruption started with an eruption of two different progressions of runny lava flows, which resulted in an older, grey basalt becoming overlain by a younger, darker black basaltic lava flow. The passive eruptions were followed by a period of explosive eruptions. This explosive activity built three overlying cinder cones that broke by the two lava flows near the end of the explosive phase of activity. The last phase of explosive activity spread tephra to the north and east of the cones. The deepest deposits near the cone are less than 3 m (10 ft); that they thin to less than a few centimetres only a few kilometres away, suggests that the explosive eruptions at Nazko Cone were fairly small. However, the last eruption from Nazko Cone could have started forest fires, since there is charcoal inside the tephra layer.

Read more about this topic:  Anahim Hotspot, Geological History

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