Misema Caldera

From Wikipedia, the free encyclopedia

The Misema Caldera is a striking 2704-2707 year old caldera in Ontario and Quebec, Canada. It is one of the calderas that form the Blake River Megacaldera Complex[1] and has a diameter of 40-80 kilometers. The caldera is also a coalescence of at least two large mafic shield volcanoes that formed more than 2703 million years ago.[2] The rim of the Misema Caldera contains a 10-15 kilometer wide inner and outer ring zone, in which many mafic ring dike complexes and subaqueous pyroclastic sediments are detected. The mafic ring dike structures may be deeper level expressions of summit calderas related to a shield volcano phase while the pyroclastic fragments could either be associated with satellite cones or the result of Misema caldera collapse.[2]

The Misema Caldera is the oldest and largest caldera associated with the Blake River Megacaldera Complex and is comparable in size to the Lake Toba caldera in Indonesia.[2]

[edit] See also

[edit] References

  1. ^ ASH FALL: Newsletter of the Volcanology and Igneous Petrology Division Geological Association of Canada Retrieved on 2007-09-24
  2. ^ a b c Blake River Group evolution: characteristics of the subaqueous Misema and New Senator calderas
 This Ontario geographical article is a stub. You can help Wikipedia by expanding it.
 This Quebec location article is a stub. You can help Wikipedia by expanding it.