- Sturgeon Lake Caldera
Infobox Mountain
Name=Sturgeon Lake Caldera
Photo=
Caption=
Elevation= approx. Unit m|455|0
Location=Ontario ,Canada
Range=
Prominence =
Coordinates = coord|49|52|13|N|91|00|10|W|type:mountain_region:CA
Topographic
Type=Caldera
Volcanic_Arc/Belt=Wabigoon greenstone belt
Age=Neoarchean
Last eruption=Neoarchean
First ascent=
Easiest route=
Listing=List of volcanoes in Canada Sturgeon Lake Caldera is a large extinct
caldera in Kenora District ofNorthwestern Ontario ,Canada . It is one the world's best preserved mineralizedNeoarchean caldera complexes, containing well-preservedmafic -intermediatepillow lava s, pillowbreccia s.hyaloclastite and peperites, submarinelava dome s and dome-associated breccia deposits. The complex is some 2.7 billion years old [ [http://www.d.umn.edu/~rmorton/ronshome/Volcanoes/calderas.html Caldera Volcanoes] Retrieved on2007-07-20 ] with a minimum strike length of Unit km|30|0.Geology
The Sturgeon Lake Caldera contains a well preserved north facing homoclinal chain of greenschist facies metamorphosed intrusive, volcanic, and sedimentary layers. This piecemeal caldera complex includes nearly Unit m|3000|0 of major subaqueously deposited intracaldera fill. Episodes of subaerial and subaqueous explosive felsic volcanism created rhyodacitic to rhyolitic
tuff s andlapilli tuffs. The caldera complex lies in the Wabigoon greenstone belt.The Sturgeon Lake Caldera contains volcanic units that outcrop over 30 kilometers from east to west with up to five separate, major ash flow tuff units with thickness ranging from 100 to 1200 meters. The Mattabi pyroclastic flow, with a thickness in excess of Unit m|800|0 and a strike length of at least Unit km|30|0, is the third and most voluminous eruptive event associated with the Sturgeon Lake Caldera. It hosts the 12-Mt Mattabi massive sulfide deposit which is interpreted to have formed on and below the seafloor, the latter through the processes of pore-space filling and replacement.
ee also
*
Volcanism in Canada
*List of volcanoes in Canada References
* [http://cat.inist.fr/?aModele=afficheN&cpsidt=15398943 CAT.INIST - Sturgeon Lake Caldera Complex]
External links
* [http://www.cseg.ca/conferences/2000/2000abstracts/356.PDF Oxygen Isotope Studies of the Archean Sturgeon Lake Caldera Complex, Northern Ontario]
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