Chautauqua Hills—Rocks and Minerals
Chautauqua Hills--Intro |
Chautauqua Hills--Rocks and Minerals
Chautauqua Hills--Places to Visit | Other regions
Download fact sheet on the rocks and minerals of the Chautauqua Hills.
Sandstone. The characteristic rocks in the Chautauqua Hills are the thick sandstones that cap the hills and are exposed along creek and river valleys. Sandstone, which is made up largely of quartz grains cemented together by calcium carbonate, iron oxide, or silica, is a common sedimentary rock. In eastern Kansas, sandstone is often interbedded with shale and limestone. It also occurs as channel deposits, cutting through older deposits of shale and limestone.
The sandstones capping the Chautauqua Hills are the Tonganoxie Sandstone Member of the Stranger Formation and Ireland Sandstone Member of the Lawrence Formation. Both are thick rock formations, the remains of deposits that filled a large, ancient river valley during the Pennsylvanian Period.
Sandstone outcrop in the Chautauqua Hills.
Some sandstones are marked by ridges and troughs that look like the ripples you'd see in loose sand in a stream, shallow lake, sea, or sand dune. By studying ripple marks preserved in sandstone and comparing them with similar marks found in today's sand, geologists can make shrewd assumptions about what the environment was like when these sandstones were deposited.
Ripple marks in Chautauqua County sandstone.
Fossil ripple marks provide information about the direction of the current, the environment, and, to a degree, the depth of the water. Some researchers believe that wind-created ripples are not preserved and that virtually all fossil ripple marks were formed in water.
Simplified diagram of the formation of ripples in water. Water current pushes individual sand or silt grains from low points (A) to high points (B), where other grains are dislodged and rolled down the slope.
Chautauqua Hills--Intro |
Chautauqua Hills--Rocks and Minerals
Chautauqua Hills--Places to Visit | Other regions
General geology, rocks and minerals, and places to visit in the state's physiographic regions (including PDF factsheets for downloading)
Information about common Kansas fossils
Photos and descriptions of sites of geologic (and other) interest in Kansas
Descriptions of various rocks and minerals found in Kansas, including mineral ID tables and hardness scale
Overviews of various geology topics, ranging from Earth's age to the state's mining history
Online guidebooks, descriptions, and photos from KGS public field trips in Kansas
