News Release, Kansas Geological Survey, Oct. 11, 2001
The new, full-color map is by Survey geologist James McCauley. It depicts the age and type of rocks at the surface of Comanche County, along with a variety of other information.
Geologic maps are a basic tool to understanding the geology of an area, and are useful in environmental issues, construction, mining, and for other purposes.
In particular, the Comanche County map shows areas where the bedrock is composed of "redbeds." These are sandstones, siltstones, and shales that are generally red or orange and have given the name "Red Hills" to this part of Kansas. These rocks were deposited during the Permian Period of geologic history, about 250 million years ago.
The Permian rocks also include layers of gypsum, which is why this same part of the state is sometimes called the Gypsum Hills.
Lying above the redbeds are rocks deposited during the Cretaceous Period, roughly 100 million years ago. These rocks include white sandstone and dark gray shale that contrasts markedly with the underlying red rocks.
"Some of these rock layers erode fairly easy, creating badlands with canyons and isolated buttes," said McCauley. "In places the gypsum has been dissolved away, forming caves and sinkholes. The redbeds, sinkholes, and caves make this one of the most scenic and geologically interesting parts of Kansas."
While the redbeds cover much of the eastern and southern part of the county, much of the rest of the county is blanketed by much younger sediments and rocks, deposited within the past few million years of geologic history. This is especially true along drainages, such as the Cimarron River, Calvary Creek, and Mule Creek, and the uplands north of Coldwater.
In addition to depicting geologic features, the map shows roads, lakes, rivers and creeks, elevation of the land surface, quarries, and railroads.
The map is drawn at the scale of 1:50,000 so that one inch on the map equals about 0.8 of a mile of actual distance. The map measures about 44 inches by about 36 inches.
More general maps of the geology of Comanche County have been produced in the past, but this is the first at this level of detail. The mapping took McCauley about three years.
Copies of the map are available from the Kansas Geological Survey, 1930 Constant, Ave, Lawrence, KS 66047, or by calling 785-864-3965. The cost is $15.00, plus $4.00 for handling and postage. Kansas residents should add 6.9% sales tax on the cost of the entire order.