Sims Corner Eskers and Kames National Natural Landmark of Douglas County, Washington, and nearby McNeil Canyon Haystack Rocks and Boulder Park natural landmarks, contain excellent examples of Pleistocene glacial landforms. Sims Corner Eskers and Kames National Natural Landmark includes classic examples of ice stagnation landforms such as glacial erratics, terminal

moraine A moraine is any accumulation of unconsolidated debris (regolith and Rock (geology), rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a gla ...

s, eskers, and kames. It is located on the Waterville Plateau of the Columbia Plateau in north central Washington state in the United States.

Geologic history

The plateau

The Sims Corner Eskers and Kames National Natural Landmark is located on the Waterville Plateau, which lies in the northwest corner of the Columbia River Plateau. The plateau is formed on top of the Columbia River Basalt Group, a large igneous province that lies across parts of the states of Washington,

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

, and

Idaho Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...

in the

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. During the middle to late

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided b ...

, one of the largest

flood basalt A flood basalt (or plateau basalt) is the result of a giant volcanic eruption or series of eruptions that covers large stretches of land or the ocean floor with basalt lava. Many flood basalts have been attributed to the onset of a hotspot (geolo ...

s ever to appear on the

earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

's surface engulfed about 163,700 km² (63,000 mile²) of the Pacific Northwest, forming a large igneous province with an estimated volume of 174,300 km³. Eruptions were most vigorous from 17–14 million years ago, when over 99% of the basalt was released. Less extensive eruptions continued from 14–6 million years ago. These lava flows have been extensively exposed by the erosion resulting from the Missoula Floods, which laid bare many layers of the basalt flows on the edges of the plateau at Grand Coulee and Moses Coulee.''Portions of this article, including a figure, are adapted from works of the United States Government, which are in the

public domain The public domain (PD) consists of all the creative work to which no Exclusive exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly Waiver, waived, or may be inapplicable. Because no one holds ...

The glacial history

Two million years ago the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

epoch began and

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 ...

glaciers A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

invaded the area. They scoured the Columbia River Plateau, reaching as far south as the middle of the Waterville Plateau highlands above the Grand Coulee and south to the head of Moses Coulee. In some areas north of the Grand Coulee they were as much as 3 km (10,000 feet) thick. Grooves in the exposed granite bedrock are still visible in the area from the movement of glaciers and numerous glacial erratics in the elevated to the northwest of the coulee.

Creation of the Foster Coulee, Moses Coulee, and Grand Coulee

The Okanogan lobe of the Cordilleran Ice Sheet moved down the Okanogan River valley and blocked the ancient route of the Columbia River, backing up water to create Glacial Lake Columbia. Initially water discharged from Glacial Lake Columbia by running up through the head of Grand Coulee and down through Foster Coulee to rejoin the Columbia River. As the glacier moved further south, Foster Coulee was cut off and the Columbia River then discharged through Moses Coulee, which runs southward slightly to the east of the ancient and current course of the Columbia. As the Okanogan lobe grew, it blocked Moses Coulee as well; the Columbia found the next lowest route through the region which was eroded to become the modern Grand Coulee. Flowing across the current Grand Coulee and Dry Falls regions, the ice age Columbia then entered the Quincy Basin and joined Crab Creek, following Crab Creek’s course southward past the Frenchman Hills and turning west to run along the north face of the Saddle Mountains and rejoin the previous and modern course of the Columbia River just above the main water gap in the Saddle Mountains, Sentinel Gap.

References

External links

U.S. National Park Service on Sims Corner Eskers and Kames

Photo gallery

Image:Glacial-Drift-PB110031.JPG, A kame among the glacial drift on the terminal moraine Image:Erratics-PB110026.JPG, Terminal moraine ( Withrow Moraine) of the Okanogan Lobe Image:Erratics-Cascades-PB110028.JPG, Multiple erratics on the terminal moraine of the Okanogan Lobe. Cascade mountains in the background. Image:Terminal-Morraine-PB110030.JPG, Multiple erratics on the terminal moraine of the Okanogan Lobe Image:Yeager-Rock-Erractic-PB110039.JPG, A glacial erratic called Yeager Rock, Waterville Plateau, Washington, US {{DEFAULTSORT:Sims Corner Eskers And Kames Protected areas of Douglas County, Washington National Natural Landmarks in Washington (state) Geology of Washington (state) Glaciology of the United States Kames Landforms of Douglas County, Washington