Misema Caldera

The Misema Caldera is a 2,704-2,707 million year old caldera in Ontario and Quebec, Canada.

Misema Caldera
Map of the Blake River Megacaldera Complex. Misema Caldera is highlighted in red.
LocationOntario-Quebec, Canada
RangeCanadian Shield
GeologyCalderas
Age2,704-2,707 MYA
Volcanic arc/beltBlake River Megacaldera Complex

Geographic extent

It is the caldera that forms the Blake River Megacaldera Complex[1] and has a diameter of 40-80 kilometres.

Composition

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 kilometre 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]

See also

References
  1. ASH FALL: Newsletter of the Volcanology and Igneous Petrology Division Geological Association of Canada Retrieved on 2007-09-24
  2. Blake River Group evolution: characteristics of the subaqueous Misema and New Senator calderas Archived 2011-07-06 at the Wayback Machine


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