Photograph by B. Edwards
Photograph by B. Edwards
Hoodoo Mountain, as seen looking to the northwest across the Iskut River
in northwestern British Columbia, is a flat-topped stratovolcano.
It has an ice cap 3 km in diameter and throughout its history the volcano
has been influenced by glacial ice, including several periods of subglacial
eruptions. Most of the volcanic deposits at Hoodoo Mountain are lava
flows; however, some pyroclastic rocks are also found at the volcano indicating
at least one period of explosive activity. The oldest eruptions of the
volcano occurred about 100 000 years ago and the most recent eruptions
about 7000 years ago. The rocks that form the volcano are peralkaline phonolite
and trachyte. Hoodoo Mountain volcanic is one of ten volcanic centers in
the Iskut volcanic field (see Iskut River
and Lava Fork), and is one of the largest peralkaline
volcanoes in the northern Cordilleran volcanic province (Edwards &
Russell 2000).
Photograph by B. Edwards
The most recent lava flows on are the northwest and southwest sides of the volcano, are largely unglaciated, and are as young as 7,000 years before present. The lava channel shown above is basically unglaciated. All recent flows exposed on the flanks of the volcano appear to have originated from beneath the current, summit-covering ice.
Photograph by B. Edwards
The Monument, on the southwestern side of Hoodoo Mountain, is the eroded
remnant of a volcanic vent that was fed by a dike. It is over 100 m in
height. In the center of the photograph are a series of relatively flat-lying,
subaerial lava flows, and the units above those are thick deposits of lava
and breccia interpretted as having formed in subglacial eruptions.
For more information about Hoodoo Mountain volcano, click
here.
-Ben Edwards, Grand Valley State University, MI
Edwards, B. 1997. Field, kinetic and thermodynamic studies of magmatic
assimilation
in the northern Cordilleran volcanic province, northwestern British
Columbia [Ph. D. thesis]:
Vancouver, Univeristy of British Columbia, 324 p.
Edwards, B.R. & Russell, J.K. 2000. The distribution, nature and
origin of Neogene-Quaternary magmatism
in the Northern Cordilleran Volcanic Province, northern Canadian Cordillera.
Geological Society of America Bulletin, v. 112, no. 8, 1280-1295.
Edwards, B.R., Anderson, R.G. & Russell J.K. 1997. Geology of the
Quaternary Hoodoo
Mountain Volcanic Complex and adjacent Paleozoic and Mesozoic basement
rocks;
parts of Hoodoo Mountain (NTS 104B/14) and Craig River (NTS 104B/11)
map areas,
northwestern British Columbia. Geological Survey of Canada Open
File Report 3321, scale 1:20 000.
Russell, J.K., Stasiuk, M.V., Page, T., Nicholls, J., Rust, A., Cross,
G., Schmok, J., Edwards, B.R.,
Hickson, C.J., & Maxwell, M. 1998. Radar studies of the Hoodoo
icecap, Iskut River region, British
Columbia; in Current Research, Part A; GSC Paper 98- 1A
Souther, J.G., and Yorath, C.J., 1992, Chapter 10, Neogene Assemblages,
in
The Cordilleran
Orogen: Canada: Gabrielse, H. and Yorath, C.J. (eds.), Geol. Survey
Can., No. 4 (also Geol.
Soc. Am., The Geology of North America, No. G-2).
Souther, J.G., 1990. Hoodoo, Canada. In Wood, C.A., & Kienle, J.
(eds.)
Volcanoes of North America, Cambridge Univ. Press: Cambridge, p. 127-28
