News Release, Kansas Geological Survey, Nov. 9, 2000
The full-color map, showing the type and age of rocks at the surface, was developed by Survey geologist Daniel Merriam.
In addition to the county's geology, the map shows roads, railroads, 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, in searching for water and mineral deposits, and in a variety of engineering and environmental uses.
Most of the county is in the Osage Cuestas region of the state, an area where the bedrock is predominately limestones and shales. These rocks were deposited during the Pennsylvanian Period of geologic history, about 300 million years ago.
In addition, much younger sands, gravels, and other geologic materials were deposited along the rivers and streams in the region, particularly along the Neosho River and its tributaries.
The map shows a number of areas, especially in the southern part of the county, where the hilltops are covered by gravels largely composed of chert (or flint). These chert gravels are unusual because the rocks are rounded, an indication that they were deposited by streams. In this area, however, the gravels generally occur on hilltops, high above streambeds. A number of small pits have been dug to mine these gravels, which are used on roads and other construction purposes. Quarries have also mined the county's limestone for crushed rock. Both types of quarries are shown on the map.
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. The map measures about 42 by 38 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 $15.00, plus $5.00 for handling. Kansas residents should add 6.9% sales tax. More information about the maps and other Survey products is available at the Survey's web site (www.kgs.ku.edu).