Near Oriska in Barnes County, North Dakota — The American Midwest (Upper Plains)
Geology of North Dakota
Photographed By Barry Swackhamer, August 29, 2020
1. Geology of North Dakota Marker
Captions: (top right) North Dakota was glaciated by ice that moved south from the Keewatin Center west of Hudson Bay. Glaciers advanced over the state many times over the last three million years. Most of the glacial features that can be seen in the state today were formed during the most recent glaciation, which ended 10,00 years ago.; (middle right) Landforms throughout the Glaciated Plains were shaped by glacial ice moving south through the area. The Red River valley is the old floor of Glacial Lake Agassiz. An extensive deposit of sand accumulated at the point where floods of water from the Sheyenne River entered Lake Agassiz. This sand has been blown into dunes that can be seen in the Sheyenne National Grasslands, near Wyndmere.; (bottom right) North Dakota is made up of a variety of different kinds of topography. This rest area is in the Glaciated Plains, a region that extends south from Canada to South Dakota. The landforms in the Glaciated Plains were shaped as glaciers flowed over the area. East of here, the flat Red River Valley formed as the floor of the Glacial Lake Agassiz. To the west, the Missouri Coteau consists of hummocky and hilly land, shaped when debris-covered stagnant glacial ice melted. Western North Dakota has erosional landforms, formed by running water and wind. The landscape in western North Dakota is much older than the glacial topography of eastern North Dakota.
The gently rolling landscape here is typical of the Glaciated Plains, a vast area that extends south from Manitoba and Saskatchewan, through northern and eastern North Dakota, into eastern South Dakota. Glaciers flowed south through this area 12,500 years ago, depositing up to several hundred feet of sediment on top of the much older "bedrock" surface. When the glaciers melted, they formed the landscape you see here today. The materials the glacier picked up as it advanced over the bedrock surface were deposited as glacial sediment , a mixture of clay, silt, sand and rocks of all sizes that is called "till." Because till is composed of sediments for many different sources and contains many different kinds of rocks and minerals, soils developed on it hare rich and fertile. Westbound travellers (sic) will cross the Sheyenne River at Valley City. The Sheyenne River is a small stream that flows in a large valley, a "meltwater trench." The valley was eroded by floodwaters in a short time when ice-dammed lakes in northern North Dakota and Saskatchewan released their water when the glacier melted back. While it was being eroded, the Sheyenne
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East bound travellers (sic) will leave the Glaciated Plains in 15 miles, entering the flat Red River Valley of the North. The Red River Valley is the former floor of Glacial Lake Agassiz. It was flooded at the end of the Ice Age between 12,000 and 9,000 years ago.
Erected by North Dakota Geological Survey and North Dakota Geological Society.
Topics. This historical marker is listed in this topic list: Natural Features.
Location. 46° 55.17′ N, 97° 44.992′ W. Marker is near Oriska, North Dakota, in Barnes County. Marker can be reached from Interstate 94 at milepost 304 near 127th Avenue Southeast. The marker is located in the Oriska Rest Area. Touch for map. Marker is in this post office area: Oriska ND 58063, United States of America. Touch for directions.
Other nearby markers. At least 2 other markers are within 7 miles of this marker, measured as the crow flies. Rest Areas in Tree Claims (here, next to this marker); Sibley Trail (approx. 6.9 miles away).
Photographed By Barry Swackhamer, August 29, 2020
2. Geology of North Dakota Marker
Credits. This page was last revised on December 20, 2020. It was originally submitted on December 20, 2020, by Barry Swackhamer of Brentwood, California. This page has been viewed 255 times since then and 104 times this year. Photos: 1, 2. submitted on December 20, 2020, by Barry Swackhamer of Brentwood, California.
