USGS/CVO Logo, click to link to National USGS Website
USGS/Cascades Volcano Observatory, Vancouver, Washington

Quaternary-age Vents in the Three Sisters Area


-- Scott, William E., and Gardner, Cynthia A., 1990,
Field trip guide to the central Oregon High Cascades, Part 1: Mount Bachelor-South Sister area: Oregon Geology, September 1990, v.42, n.5: Part 2: Bend Area: Oregon Geology, September 1990, v.42, n.6

Compilation of vents of Quaternary age and faults in the Three Sisters area (Scott, 1987). Triangles are stratovolcanoes; circles are vents of mafic (basalt and basaltic andesite), mostly monogenetic volcanoes; squares are vents of silicic (dacite and rhyolite) lava domes and flows. Numerous silicic vents on the flanks of south and Middle Sister are not shown. Solid symbols represent vents of latest Quaternary (>15,000 years) age; open symbols are vents of pre-latest Quaternary age. ... Heavy lines are faults; bar and ball on downthrown side. Crossed lines are fissures. ...


Map, Quaternary age Faults in Three Sisters Area

Return to:
[Report Menu] ...
[Oregon High Cascades Menu] ...

CVO HomePage Volcanoes of the World Menu Mount St. Helens Menu Living With Volcanoes Menu Publications and Reports Menu Volcano Monitoring Menu Servers and Useful Sites Menu Volcano Hazards Menu Research and Projects Menu Educational Outreach Menu Hazards, Features, and Terminology Menu Maps and Graphics Menu CVO Photo Archives Menu Conversion Tables CVO Index - Search Our Site ButtonBar
URL for CVO HomePage is: <http://vulcan.wr.usgs.gov/home.html>
URL for this page is: <http://vulcan.wr.usgs.gov/Volcanoes/Oregon/HighCascades/Publications/FieldTripGuide/three_sisters_quaternary_age_vents.html>
If you have questions or comments please contact: <GS-CVO-WEB@usgs.gov>
02/03/06, Lyn Topinka