New geologic map of Cherokee County available from Kansas Geological Survey

LAWRENCE -- A new full-color map, available from the Kansas Geological Survey, based at the University of Kansas, shows the geology at the surface of Cherokee County, in extreme southeastern Kansas.

Geologic maps show the age and type of rocks at the earth's surface. Because of southeastern Kansas' long history of coal, lead and zinc mining, a geologic map is particularly important in this region.

In addition to depicting the county's surface geology and old mines, the map shows towns, 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.

As depicted on the map, bedrock in the extreme southeastern corner of the county is mainly limestone. These are the oldest rocks exposed at the surface in Kansas, deposited during the Mississippian Period of geologic history, about 330 million years ago. This area, generally along the eastern edge of the county and especially prominent south and east of the Spring River, is part of the Ozark Plateau, which extends into Missouri, Oklahoma and Arkansas.

These Mississippian-age rocks were mined for lead and zinc from the 1870s to 1970. The map also shows locations of mine tailings (or waste rock that was left behind after the ore was removed).

Much of the rest of the county is covered by limestones and shales deposited in the Pennsylvanian Period, also known as the Coal Age. These rocks are roughly 300 million years old, slightly younger than the Mississippian rocks, and are the source of the coals that were mined in much of the county. The map also shows locations where coal was mined and strip pits were left behind.

Parts of the rest of the county, especially along rivers such as the Spring, the Neosho, the Cherry Creek and the Cow Creek, are mantled with much more recent sediments, such as sands and gravels, that were deposited by the rivers.

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 on the ground. Independent geologist Alan Bennison, working under a contract with the Survey, drew the map.

Copies of the new map are available from the Kansas Geological Survey, 1930 Constant Ave., Lawrence, KS 66047; phone (785) 864-3965. The cost is $15, plus $4 for handling and postage. Kansas residents should add 7.3 percent sales tax on 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.