Summary
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. | |
| Location | Ontario-Quebec, Canada |
| Range | Canadian Shield |
| Age | 2,704-2,707 MYA |
| Volcanic arc/belt | Blake River Megacaldera Complex |
Geographic extent edit
It is the caldera that forms the Blake River Megacaldera Complex[1] and has a diameter of 40-80 kilometres.
Composition edit
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]
Misema Caldera is the oldest and largest caldera associated with the Blake River Megacaldera Complex and is comparable in size to Lake Toba caldera in Indonesia.[2]
See also edit
References edit
- ^ ASH FALL: Newsletter of the Volcanology and Igneous Petrology Division Geological Association of Canada Retrieved on 2007-09-24
- ^ a b c Blake River Group evolution: characteristics of the subaqueous Misema and New Senator calderas Archived 2011-07-06 at the Wayback Machine
48°23′N 79°27′W / 48.39°N 79.45°W