Field trip 3 Columbia River Gorge
Answer as many of the numbered questions as you can. Draw sketches at every field location of any geologic features. Remember to use a scale. Ask your instructor if you don’t understand what to do. Also, elaborate on at least two of the field sites in a one page word-processed summary on a separate piece of paper. Consult web references and any of the references listed at the end of this guide. They can be found on hold in the library. Clean out the vans at the end of this trip. I will give one pop quiz question for every item found in the vans after the trip.
Overview of trip 3: We will leave the
MP 13 rest stop if we need one???
Exit onto I-205 bypass
Get off at Troutdale –exit 17—rest stop at McDonalds/Burger King
east and turn left (north) toward Troutdale airport—go under I-84 and continue
straight past Wendy’s on right and airport on left. After going around a curve
to right turn right on
STOP 1. TROUTDALE
AIRPORT EXPOSURE OF
STOP 2. TROUTDALE GRAVELS ALONG
OPTIONAL STOP: CROWN POINT. (REST ROOMS)
STOP: ONEATA GORGE,
OPTIONAL STOP: EAGLE CREEK TRAIL ALONG I-84.
Field trip activities: (note 1 Ma = 1 mega annum or 1 my; 1 ka = 1 kiloannum or 1,000 years)
69 – 64: Slightly south of Chehalis we ascend what early 19th
century pioneers called “mud mountain”. This is the highland that forms the divide between the Newaukum-Chehalis
~MP 63: Near Winlock descend to a lower, younger terrace. Does this terrace have less or more relief than that of the Logan Hill Formation? This terrace is inferred to be only ~0.5 -0.3 Ma and is also interpreted to consist of outwash material from the Cascade highlands. What was the source of the “outwash”?
60: Descend to another, younger terrace, also very flat. This is interpreted as
glacial outwash from the alpine glaciation event named the Evans
Creek glaciation, which lasted from about 22 ka to 15 ka. Cross the
49: SR 503 to
Much of the land along the highway here is veneered by sediments deposited by the Missoula Floods. The floods reached as high as 150 ft above sea level (SL) near here.
39. At Kelso, one of the most destructive landslides in the history of the
http://web.umr.edu/~rogersda/professional_experience/aldercrest-banyon_ls.htm or elsewhere on the web or in libraries. What caused the landslide?
south of the
There is a very thick exposure of the Goble Volcanics at about MP 31.8 on the West side of the highway called Drays Mound. This may have been a volcanic vent area. Note dikes exposed in the outcrops.
the bedrock constriction here (narrowing of the valley) is composed of Columbia
River Basalts. This constriction served to hydraulically dam the great Missoula
Floods, causing them to backflood as far south as
Merge onto I-205: From the I-205 south to SR 14 we will be traversing
sand and gravel terraces deposited by the late Pleistocene Missoula Floods. As
we cross the
Head east on I-84 and get off at Exit 17, Troutdale. We will pull into the McDonalds or Jubitz for a break.
we’ll head east, turn left toward the
Airport site and go back toward I-84. Turn right at light and drive west on the
access road, but turn left at Marine Drive and go back under I-84, then left
again past McDonalds. This time TURN RIGHT at the light and go south past
outlet stores and up a grade—at light take left into the town of
CARFULLY cross the road to the outcrop. Be wary of falling rocks and debris at the outcrop!
STOP 2. OUTCROP OF PLEISTOCENE AND
PLIOCENE AGE TROUTDALE FORMATION GRAVELS AND SANDSTONES. The Troutdale sediments are interpreted to have been
deposited by the ancestral
on the highway, going straight past the Oxbow turnoff. There are buried
subfossil trees at
3 miles past
STOP 3. WOMENS FORUM. We will park and walk to the north to the interpretive
sign. At the viewpoint, sketch the landscape you see and label it as we discuss
the significance and composition of various landforms such as
STOP 4. Latourell FALLS. There are rest rooms north of the road and down a path. We will walk to the falls to see the Sentinel Bluffs Member of the Grande Ronde Basalt that forms the falls. Along the trails is platy jointed dacite of the Oligocene age Skamania Volcanics. Quickly sketch the falls labeling the colonnade and entablature components of the lava flow. Why do columns form in lavas?
STOP 5. MULTNOMAH FALLS. We will stop here for 20 minutes. You can hike up to the bridge, but please go no farther. Note the many lava flows exposed in the falls! Allen (1979) has a sketch showing the different flows here.
OPTIONAL STOP: EAGLE CREEK We may stop here to see the fragmental deposits of the lower Miocene Eagle Creek Formation, which originated a composite volcano north of here. The deposits include lahars and pyroclastic flows. A buried petrified tree and is visible along the trail. Draw and label a sketch.
=>CAUTION! The trail here is locally a cliff with 15 ft drop to the creek. Be mindful of the edge!
References (many on hold in Kirk Library)
E., 1979, The magnificent gateway--A layman's guide to the geology of the
Columbia River gorge: Timber Press [
Eliot; Burns, Marjorie; Sargent, Sam C., 1986,
Cataclysms on the
Marvin H.; Tolan, Terry L., 1987, Columbia River
gorge--The geologic evolution of the Columbia River in northwestern
Kenneth A.; Pringle, Patrick T., 1986, Post-glacial lahars of the
Cameron, Kenneth A.; Pringle, Patrick T., 1987, A detailed chronology of the most recent major eruptive period at Mount Hood, Oregon: Geological Society of America Bulletin, v. 99, no. 6, p. 845-851. [I will make this available via Angel]
Dethier, David P., 1988, The soil chronosequence along the Cowlitz River, Washington: U.S. Geological Survey Bulletin 1590-F, 47 p.
Lawrence, Donald Buermann; Lawrence, Elizabeth G., 1958, Bridge of the Gods legend--Its origin, history, and dating: Mazama, v. 40, no. 13, p. 33-41.
J. E, 2004, The Evolving Landscape of the Columbia River Gorge: Lewis and Clark
and Cataclysms on the
O'Connor, J. E.; Pierson, T. C.; Atwater, B.F.; Turner, D.; Pringle, P.T., 1996, An exceptionally large Columbia River Flood between 500 and 600 years ago—Breaching of the Bridge-of-the-Gods landslide?: Geological Society of America Meeting (Cordilleran), Portland, Oregon, v. 28, no. 5, p. 97.
A., 1977, Large landslides of the Columbia River gorge,
Pierson, T.C.; Pringle, P.T.; Cameron, K.A., 2011, Magnitude and timing of downstream channel aggradation and degradation in response to a dome-building eruption at Mount Hood, Oregon. Geological Society of America Bulletin. v. 123, no. 1–2, p. 3–20. [Accessed until January 2013 at: http://bulletin.geoscienceworld.org/cgi/content/full/123/1-2/3?ijkey=4xxL7.WGKnpY.&keytype=ref&siteid=gsabull
Pringle, Patrick T., 2004, Dendrochronology research supported by Murdock Trust, DGER News, v. 1. no. 1., p. 2. [accessed on February 16, 2005 at ]
Pringle, Patrick T., 2008, Roadside geology of Mount Rainier National Park and vicinity: Washington Division of Geology and Earth Resources Information Circular 107, 191 p. [Accessed on June 3, 2008 at http://www.dnr.wa.gov/ResearchScience/Topics/GeologyPublicationsLibrary/Pages/pub_ic107.aspx ]
Pringle, Patrick, 2009, The Bonneville slide. Explorations: Columbia Gorge Interpretive Center Museum, Fall–Winter 2009, p. 2–3. [accessed August 12, 2010 via http://www.centralia.edu/academics/earthscience/pringle/pubs/pringle_2009_bonneville_slide_errata.doc
Pringle, Patrick T.; Pierson, Thomas C.; Cameron, Kenneth A., 2002, A circa A.D. 1781 eruption and lahars at Mount Hood, Oregon—Evidence from tree-ring dating and from observations of Lewis and Clark in 1805-6 [abstract]: Geological Society of America Abstracts with Programs, v. 34, no. 6, p. 511. [accessed on June 3, 2008 at http://gsa.confex.com/gsa/2002AM/finalprogram/abstract_46581.htm ]
Pringle, P.T.; Pierson, T.C.; Cameron, K.A.; Sheppard, P.R, 2010, Late 18th century Old Maid eruption and lahars at Mount Hood, Oregon (USA) dated with tree rings and historical observations, IN Tree-Ring Analysis in Natural Hazards Research, Stoffel, M., Bollschweiler, M., Butler, D.R., Luckman, B.H. (eds.). Springer, p. 487–491. [I will put this paper on the Angel site]
Schuster, Robert L.; Pringle, Patrick T., 2002, Engineering history and impacts of the Bonneville landslide, Columbia River gorge, Washington-Oregon, USA. IN Rybar, Jan; Stemberk, Joseph; Wagner, Peter, editors, Landslides--Proceedings of the First European Conference on Landslides: A. A. Balkema, p. 689-699.
Tolan, Terry L.; Beeson, Marvin H.; Vogt, Beverly F., 1984, Exploring the Neogene history of the Columbia River--Discussion and geologic field trip guide to the Columbia River gorge; Part II, Road log and comments: Oregon Geology, v. 46, no. 9, p. 103-112. [Accessed on April 30, 2011 at http://www.oregongeology.org/pubs/og/OGv46n09.pdf ]
Richard B., Jr., 1985, Case for periodic, colossal jokulhlaups from Pleistocene
Wang, Yumei; Hofmeister, R. Jon; McConnell, Vicki S.; Burns, Scott F.; Pringle, Patrick T.; Peterson, Gary L., 2002, Columbia River gorge landslides. IN Moore, G. W., editor, Field guide to geologic processes in Cascadia: Oregon Department of Geology and Mineral Industries Special Paper 36, p. 273-287.
Weaver, Russ; Pringle, Patrick T., 2003, Use of dendrochronology to date and better understand the Bonneville landslide, Columbia River Gorge, Washington [abstract]: Geological Society of America Abstracts with Programs, v. 35, no. 6, p. 80. [accessed on April 1, 2007 at http://gsa.confex.com/gsa/2003AM/finalprogram/abstract_67682.htm ]
Karl W., 2004, Geologic field trip to the Aldercrest-Banyon