Quartzite is a metamorphic rock that forms when sandstone is altered, or metamorphosed, through heat, pressure, and chemical changes. Quartzite boulders that litter hillsides in parts of northeastern Kansas did not originate here but were carried in from the north about 700,000 years ago by massive sheets of ice.
During the Pleistocene Epoch, also known as the Ice Age, glaciers dipped into the northeastern corner of the state at least twice, dragging along sediment ranging in size from silt particles to boulders. The boulders were eroded off outcrops around the intersection of Iowa, Minnesota, and South Dakota. Known as Sioux quartzite, the rock ranges in color from pink to reddish purple. Unlike sandstone, it is too hard to scratch with a knife.
In Kansas, quartzite boulders are found only in the Glaciated Region, unless they have been transported elsewhere by people.
Buchanan, R., 2010, Kansas Geology: An Introduction to Landscapes, Rocks, Minerals, and Fossils (2nd ed.): Lawrence, Kansas, University Press of Kansas, 240 p.
Buchanan, R., and McCauley, J. R., 2010, Roadside Kansas: A Traveler's Guide to Its Geology and Landmarks (2nd ed.): Lawrence, Kansas, University Press of Kansas, 392 p.
Kansas Rocks and Minerals, Kansas Geological Survey Educational Series 2
Glaciers in Kansas: Kansas Geological Survey Public Information Circular 28