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LAWRENCE -- A new geologic map of Shawnee County, showing the age and type of rocks at the earth's surface, is available from the Kansas Geological Survey, based at the University of Kansas.
In addition to depicting the county's surface geology, the map shows roads, railroads, airports, quarries, streams, lakes and other features. Because geologic maps show the rock formations likely to be encountered in a given location, they are useful in construction, in understanding soils and agriculture, in searching for water and mineral deposits, and in a variety of engineering and environmental uses.
This map is based on field work done in the late 1950s by U.S. Geological Survey geologists William D. Johnson Jr., Holly C. Wagner and W.L. Adkinson. The map was originally published in 1967 and has been out of print for many years. The new version was produced by KGS automated cartography staff.
"This new map combines the original high-quality geologic map with an updated base map, making it more useful," said Larry Brady, coordinator of the Survey's geologic mapping program. "The map will be important for future infrastructure projects in the Topeka area."
Most of Shawnee County is in the glaciated region of Kansas, the area characterized by deposits of silt, gravel and boulders that were left behind by the glaciers that covered northeastern Kansas about 600,000 years ago. These glacial deposits cover the much older limestones, sandstones and shales that were deposited during the late Pennsylvanian and early Permian Periods of geologic time, from about 300 million to 280 million years ago.
The map shows a number of slopes covered with glacial deposits. These deposits are more widespread north of the Kansas River, and the map shows several pits where the glacial material was mined for gravel. No glaciation occurred south of the Wakarusa River in Shawnee County.
The full-color map is drawn at a scale of 1:50,000, so that 1 inch on the map equals about 3/4 mile of actual distance. It measures about 44 inches by 37 inches.
Copies of the new map are available from the Kansas Geological Survey, 1930 Constant Ave., Lawrence, KS 66047 (or phone 785-864-3965). The cost is $15 plus $4 for handling and postage. Kansas residents should add 7.3 percent sales tax to the cost of the entire order. More information about the maps and other Survey products is available at the Survey's Web site, www.kgs.ku.edu
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