The Corfu Slide is a

geological Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth s ...

feature located on the north slope of the Saddle Mountains above Crab Creek near the

Columbia River The Columbia River (Upper Chinook language, Upper Chinook: ' or '; Sahaptin language, Sahaptin: ''Nch’i-Wàna'' or ''Nchi wana''; Sinixt dialect'' '') is the largest river in the Pacific Northwest region of North America. The river headwater ...

in eastern

Washington Washington most commonly refers to: * George Washington (1732–1799), the first president of the United States * Washington (state), a state in the Pacific Northwest of the United States * Washington, D.C., the capital of the United States ** A ...

. It consists of 24 separate slides that cover approximately 18-20 square kilometers (7 to 8 miles²)Thirteen (13) square kilometers per the Lewis reference. The most recent reference is quoted in the text here. and contains a volume of material of about 1 cubic kilometer.

Geologic History

Geologic evidence supports the view that the slide occurred 13,000 to 15,000 years ago as the result of undercutting which occurred during the Missoula Floods associated with the retreat of glaciers during the last

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages, and g ...

. Water flowing through the

Channeled Scablands The Channeled Scablands are a relatively barren and soil-free region of interconnected relict and dry flood channels, coulees and cataracts eroded into Palouse loess and the typically flat-lying basalt flows that remain after cataclysmic floods ...

split into two streams just upstream of the Corfu Slide, with part flowing to the east to pass over the low end of the Saddle Mountains and part flowing westward to pass through Sentinel Gap in the Saddle Mountains. The force of the water diverted to the west impinged on the base of the Corfu Slide area, causing erosion. At least some of the slide occurred before the final Missoula Floods as the older landslide debris has been eroded and smoothed by water flow.

Location

The best viewpoint for the landslide is from its top on the crest of the Saddle Mountains. However it is visible from a number of points, including a road which traverses the lower portions of the slide.

References and comments

Landforms of Washington (state) {{Washington-geologic-formation-stub