Guidebook—Geology of Northeastern Kansas

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color photo of hilltop covered with pink boulders

Sioux quartzite on hillside in Wabaunsee County.

Stop 2 to Stop 3

From Stop 2, the route backtracks on K-4 towards Dover and then heads north on Carlson Road, along the Wabaunsee-Shawnee county line. Just a little over a mile north of K-4, hard, pink boulders of Sioux quartzite can be seen in the pastures on either side of the road.

Stop 3—Glacial Boulders

The glacial boulders that litter the pastures along this road, called Sioux quartzite, are evidence of glaciation. Sioux quartzite occurs near Sioux Falls, South Dakota, and derives from ancient sandstone that was fused into blocks of solid quartz over a billion years ago. These boulders were carried into Kansas by a glacier about 600,000 to 700,000 years ago. More about the Glaciated Region and Sioux quartzite boulders in Kansas.

These foreign boulders, called erratics by geologists, are tell-tale markers of the presence of glacial ice during the Pleistocene and can be used to mark the extent of the glaciation because only the immense force of moving ice is capable of carrying rocks this big any appreciable distance. Glacial deposits are not found a short distance south of here, so we are very near the terminus of the glacier in Kansas.

Also in this area are other glacial deposits, including a former gravel pit, which operated until 1952. The rocks at the gravel pit are composed of rounded gravel, pebbles, cobbles, and boulders of limestone, chert, quartzite, and granites. These rocks are poorly sorted and some layers are naturally cemented by calcium carbonate. The rounded nature of these rocks and their large size indicates that they traveled some distance in a strongly flowing river, yet the site is five miles south and more than 150 feet above the nearest large river, the Kansas. The presence of relatively soft limestone pebbles and cobbles suggests that this material didn't travel very far. Geologists refer to such deposits as glacial drift, and, like the boulders of Sioux quartzite, this deposit was left behind by the glacier that entered Kansas roughly 700,000 years ago. Drift is a term that originated in Britain to describe the diverse mixture of rock and clay that covers much of that island. Early beliefs were that this material "drifted" in during the Great Flood of the Old Testament. We now know that continental glaciation formed these deposits, yet the name drift persists. Drift is a general term for deposits associated with glacial ice and includes river and lake deposits formed by the melting glacial waters. A deposit formed directly by glacial ice is known by a Scottish word, till.

color photo of small rounded rocks and pebbles in dirt outcrop

Glacial drift at former gravel pit, eastern edge of Wabaunsee County.

This deposit most likely formed when the glacier occupied the Kansas River valley, damming its southern tributaries, creating a temporary lake and diverting the drainage to upland areas such as this. Meltwater from the glacier carried part of the huge, diverse sedimentary load from the glacier across present drainage divides and deposited it locally on some of the uplands, as at the former gravel pit and in terrace deposits along some of the larger streams such as Shunganunga Creek and the Wakarusa River. Glacial drift covers a large part of northeastern Kansas, north of the Kansas River and east of the Big Blue River. Deposits of sand and gravel such as this make excellent aquifers because of the porosity and permeability provided by the coarse grain sizes. These deposits feed small springs that drain into Vassar Creek just down the hill, and drift-related aquifers are important ground-water resources in the glaciated region of Kansas. The gravel itself is an aggregate resource and this pit was operated to provide gravel for county roads.

Directions to Stop 3

From Dover, Kansas, drive one-half mile west on Kansas Highway 4 to Carlson Road. Turn north (right). About 1.25 miles north, glacial boulders (some up to four feet in diameter) can be seen in the pastures to the west. For the next mile or two, boulders are scattered across pastures, found along fence lines, and stacked around mailboxes on both sides of the road. Carlson Road meets I-70 at Exit 346, about 6.5 miles north of its intersection with K-4.

Stop 3 to Stop 4

From Stop 3, the route continues north on the county line road. This upland area is underlain by Pennsylvanian limestones and shales, but is mantled by glacial deposits. The use of center pivot irrigation systems along this road shows that, locally, this glacial material is an aquifer (a water-bearing rock formation). Generally, the bedrock in this part of the state does not provide enough water to allow crop irrigation.

Heading east along I-70, the route travels down section--in other words, it moves from younger to older bedrock. As the route passes through Topeka, between Shunganunga Creek and Deer Creek, it passes through roadcuts in the Topeka Limestone (see stratigraphic column), rocks that also crop out at Stop 4.

As the route follows U.S. 40 and K-4, it follows Deer Creek to the north (the Deer Creek Limestone that crops out along the turnpike in western Douglas County is named for exposures along this creek). As K-4 turns to the north, the route crosses the floodplain of the Kansas River. Alluvial deposits in the Kansas River valley are up to 80 feet thick in this area and saturated with water. The Kansas River is an important source of surface water in northeast Kansas, and its saturated alluvium is a major aquifer as well. After crossing the Kansas River, the highway climbs onto Calhoun Bluff, the namesake of the Calhoun Shale. The upper part of the Calhoun Shale crops out at Stop 4.

This guidebook is also available in print form as Kansas Geological Survey, Open-file Report 2000-55, from KGS Publications Sales office, 785-864-3965.

Unless noted otherwise, illustrations by Jennifer Sims, Kansas Geological Survey; photographs by John Charlton, Kansas Geological Survey. Text by Jim McCauley, Liz Brosius, Rex Buchanan, and Bob Sawin, Kansas Geological Survey.

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