British Columbia, Canada

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British Columbia, Canada
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Regional Tectonic Setting
Appx. Location of the Nazko cone
1.2 to 4.7 cm/yr
(Figure Geological Survey of Canada)
On the west cost the Pacific Plate is segmented
into smaller plates, which subduct easterly
underneath the North American Plate.
(Figure Geological Survey of Canada)
The Nazko cone is attributed to the Anahim
hotspot which is still active today.
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Anahim Volcanic Belt
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Anahim Volcanic Belt
http//gsc.nrcan.gc.ca/volcanoes/map/map_e.php?id
avb
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(No Transcript)
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Itcha Range and Nazco cone
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Itcha Range, Rainbow range and Ilgachuz range
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Nazco cone and its surroundings
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Nazco area
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Nazco cone (zoomed in)
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Nazco Cone
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The Ilgachuz Range

• Located between the Rainbow and Itcha Ranges
• Formed by hotspot volcanism
• Active during the Pliocene
• One extinct shield volcano created into a range
  by 5 million years of erosion
• Created by two chemically separate magmatic
  periods
• Early complex series of trachyte and rhyolite
  eruptions
• Late extrusion of a sequence of basaltic lava
  flows.
• Evacuation of the volcanos magma chamber
  resulted in the failure of one or more centrally
  located calderas.

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Itcha Range
www.skimountaineer.com/ROF/ROF.php?nameItcha
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Gov Canada Website http//gsc.nrcan.gc.ca/volcano
es/map/map_e.php?idavb_2
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Rainbow Range

• Miocene, 8 MYA
• Peralkaline shield volcano
• Low-dome like cone
• 30 km diameter
• Tsisutl Peak 2495 m
• Lava Fragmental Rocks

http//www.skimountaineer.com/ROF/ROF.php?nameRai
nbow