News Release, Kansas Geological Survey, May 11, 2006
LAWRENCE--A new full-color map of the geology at the surface in Osborne County is now available from the Kansas Geological Survey, based at the University of Kansas.
The map shows the type and age of rock layers found at the surface or immediately under the vegetation and soil. In Osborne County much of the surface bedrock is Cretaceous-age limestone and shale deposited about 75 million years ago. Among the more common rock formations is the Blue Hill shale, which is capped by Fort Hays limestone. Although not as durable as the harder, widely used Fencepost limestone found just to the south and east of Osborne County, the thick, blocky Fort Hays limestone also has been quarried and used to construct buildings and fence posts in the area.
The main source of the county's water, the Solomon River, has formed floodplains containing more recent and more fertile deposits of sand, silt, and gravel. All tributaries in the county drain to the Solomon River except in the far southern portion where they drain south to the Saline River. Remnants of the water-bearing Ogallala Formation, widespread farther west in the state, are found in the southwest corner of the county, verifying that streams carrying material produced by the formation of the Rocky Mountains once flowed at least that far east.
Besides surface rocks, rivers, and streams, the map features towns, roads--from federal highways to unimproved roadways--lakes and ponds, political boundaries, and contour lines indicating elevations and the steepness of the terrain. As can be seen on the map, the location of major cultural features, such as the towns of Osborne and Downs, U.S. Highway 24, and railroads, were heavily influenced by the geology. All are mainly within the Solomon River Valley. Also shown is the Glen Elder State Wildlife Area in the northeastern corner of the county.
Because geologic maps show the rock formations likely to be encountered in a given location, they are useful for understanding soils and agriculture, searching for water and mineral deposits, and for a variety of engineering and environmental enterprises.
"Such maps can also be integrated into GIS and remote sensing for research in geophysics, geography, archaeology, biology, and land development," says Ken Neuhauser, author of the map and professor of geology at Fort Hays State University.
The map is drawn at a scale of 1:50,000 so that one inch on the map equals about 3/4 mile of actual distance and measures 49 inches by 45 inches. It is the first Kansas Geological Survey county geologic map to be printed with a digital-elevation-model [DEM], which adds a unique and dramatic '3-D' look to the appearance of the map.
Copies of the new map are available from the Kansas Geological Survey, 1930 Constant Ave., Lawrence, KS 66047-3726 (or phone 785-864-3965). The cost is $15.00, plus $4.00 for handling and postage. Kansas residents should call for specific sales tax to be charged. More information about the maps and other KGS products is available at the Survey's web site (www.kgs.ku.edu).