Field Trip Leaders:Karl Lillquist, Geography Department, CWU

Nick Zentner, Geological Sciences Department, CWU

Sunday 26 September 2010

Ice Age Floods Institute–Ellensburg Chapter

Waterville Plateau Field Trip

During the Late Glacial Maximum, the Cordilleran Ice Sheet flowed down both sides of the North Cascades, overwhelming the crest of the range and connecting the Okanogan lobe with Puget Lowland ice across the North Cascades. The Okanogan Lobe reached ~50 km south of the Columbia River on the Waterville Plateau, where it built a massive end moraine and left a museum of glacial landforms magnificently preserved in the arid climate.(Easterbrook, 2003, p. 153)

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Field Trip Itinerary8:00 am Depart from CWU’s Hebeler Hall Parking Lot

10:00 Arrive at Stop 1–Dry Falls 11:00 Depart from Dry Falls11:15 Arrive at Stop 2–”Isaak’s Corner”11:45 Depart from Isaak’s Corner12:00 pm Arrive at Stop 3—Sims Corner Esker12:30 Depart from Sims Corner Esker1:00 Arrive at Stop 4—Chalk Hills2:00 Depart from Chalk Hills2:15 Arrive at Stop 5—Mansfield2:45 Depart from Mansfield3:00 Arrive at Stop 6—Withrow3:30 Depart from Withrow3:45 Arrive at Stop 7-- Moses Coulee4:15 Depart from Moses Coulee6:00 Arrive in Ellensburg 3

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2

3

4

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4Figure 1. Our route. Numbers indicatefield trip stops (Washington Highway Map).

Figure 2. The Columbia Plateau and the areal extent of the Columbia River Basalt Group, the four major structural-tectonic subprovinces (the Yakima Fold Belt, Palouse, Blue Mountains, and Clearwater-Weiser embayments), the Pasco Basin, the Olympic-Wallowa lineament, and the CLEW, which is the central portion of the OWL that passes through the western part of the Columbia Plateau (Reidel & Campbell, 1989, p. 281).

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6

Figure 3. Generalized map of major faults and folds along the western margin of the Columbia Plateau and Yakima Fold Belt. General area of stops 1-7 included within rectangle (from Reidel & Campbell, 1989, p. 281).

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Figure 4. Map of Columbia River Valley and tributaries. Irregular small dot pattern shows maximum area of Glacial Lake Missoula east of Purcell Trench Ice Lobe and maximum extent of Glacial Lake Columbia east ofOkanogan Lobe. Dashed line pattern shows area that, in addition to these lakes, was swept by the Missoula Floods. Late Wisconsin Cordilleran Icesheet margin shown as heavy dot pattern. Large dots indicate: B-Burlingame Canyon; L-Latah Creek; M-Mabton, N-Ninemile Creek; P-Priest Valley; S-Sanpoil Valley, and Z-Zillah (from Waitt, 1995, p. 1K-4).

Stop 1

8

DryFalls

1

To Coulee

City

To SoapLake

Figure 5. Dry Falls & Vicinity.

Figure 6. Map of CordilleranIcesheet and related features on Columbia Plateau andNorthern Rocky Mountains(from Richmond et al, 1965,p. 232).

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2PilotRock

Stop 2

10

To SimsCorner

To Coulee

City Figure 7. “Isaak’s Corner” & Vicinity.

Figure 8. Marginal landformsof continental glaciers (fromStrahler, 1960, p. 402).

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Figure 9. Distribution of large scale glacial landforms and inferred ice flow directions. Purple represents undifferentiated glacial drift. Eskers formed during deglaciation. Successive ice margins during retreat are also shown. Note position of Dry Falls (DF) (from Kovanen and Slaymaker, 2004, p. 553).

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DF

3

Stop 3

Pot Hills

WA 172To SimsCornerTo Mansfield

Esker

13Figure 10. Sims Corner esker.

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Figure 11. Esker and kame origins(Lobeck, 1939, p. 312).

Figure 12. Sequence of late Pleistocene flood events on theWaterville Plateau (Hanson,

1970, p. 129).

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Stop 4

BadlandTopography

LakeSediments

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Figure 13. Chalk Hills & vicinity.

To Mansfield

ToBridgeport

To Coulee City

Figure 14. Glacial Lakes of FosterCreek Watershed(from Martin, 2001).

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Stop 6 To Mansfield

To Withrow

6

Glaciated

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Figure 15. Withrow Moraine.Dates from Swanson & Caffee(2001) and Brooks & Crider2007).

Stop 7

7

To Waterville

To Ephrata 19

Figure 16. Upper Moses Coulee.

Useful References• Baker, V.R. 1987. Dry Falls of the Channeled Scabland, Washington. Pp. 369-372 in M.L. Hill, ed., Centennial

Field Volume 1. Cordilleran Section of the Geological Society of America, Denver, CO.• Brooks, J.M. and J.G. Crider. 2007. Cosmogenic-Nuclide ages from the Okanogan Lobe of the Cordilleran Ice

Sheet and associated outburst flood erratics. Geological Society of America Abstracts with Programs, Cordilleran Section, 103rd Annual Meeting. Bellingham.

• Easterbrook, D.J. 2003. Cordilleran Ice Sheet Glaciation of the Puget Lowland and Columbia Plateau, and alpine glaciation of the North Cascade Range. Pp. 137-157 in Swanson, T.W., ed., Western Cordillera and Adjacent Areas. Geological Society of America Field Guide 4, Boulder, CO.

• Hanson, L.G. 1970. The Origin and Development of Moses Coulee and Other Scabland Features on the Waterville Plateau, Washington. PhD Dissertation, University of Washington.

• Kovanen, D.J. and O. Slaymaker. 2004. Glacial imprints of the Okanogan Lobe, southern margin of the Cordilleran Ice Sheet. Journal of Quaternary Science 19 (6): 547-565.

• Lobeck,. A.K. 1939. Geomorphology: An Introduction to the Study of Landscapes. McGraw-Hill Book Company. New York.

• Martin, K.W. 2001. Late Pleistocene Glacial Lakes of Foster Creek Watershed, Washington. Unpublished undergraduate research report, Geography and Land Studies Department, CWU.

• Reidel, S.P. and N.P. Campbell. 1989. Structure of the Yakima Fold Belt, central Washington. Pp. 275-306 in N.L. Joseph, ed., Geologic Guidebook for Washington and Adjacent Areas. Washington Division of Geology and Earth Resources Information Circular 86. Olympia, WA.

• Richmond, G.M., R. Fryxell, G.E. Neff and P.L. Weis. 1965. The Cordilleran Ice Sheet of the Northern Rocky Mountains, and related Quaternary History of the Columbia Plateau. Pp. 231-242 in H.E. Wright, Jr. and D.G. Frey, eds., The Quaternary of the United States. Princeton University Press, Princeton, NJ.

• Strahler, A.N. 1960. Physical Geography (2nd edition). John Wiley. New York.• Swanson, T.W. and M.L. Caffee. 2001. Determination of 36Cl production rates derived from well-dated

deglaciation surfaces of Whidbey and Fidalgo Islands, Washington. Quaternary Research 56: 366-382.• Waitt, R.B. 1994. Scores of gigantic, successively smaller Lake Missoula floods through Channeled Scabland

and Columbia Valley. Pp. 1K-1-88 in D.A. Swanson and R.A. Haugerud, eds., Geologic Field Trips in the Pacific Northwest: 1994 Geological Society of America Annual Meeting. Seattle.

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