Flying back to Denver yesterday, clouds obscured the landscape of Missouri and eastern Kansas. When that curtain was finally removed, near WaKeeney, I was looking down on the flat terrain of west-central Kansas, where irregular, white formations broke the squares of cropland. Most of these stretched west to east just south of a river that meandered across the Great Plains.
What I saw were outcrops of Cretaceous chalk, deposited in a vast sea that covered this region some 100 million years ago. While most of the chalk is buried beneath younger Tertiary sediments, eroded from the Rockies, escarpments of white rock are exposed by rivers and their tributaries that sculpt the landscape, carrying away the overlying deposits. In this case, the Saline River has eroded the Plains, providing the aerial spectacle that I encountered.
On my many road trips across the Great Plains, I would rarely see such outcrops of chalk unless I made side excursions to sites such as Castle Rock, south of Quinter. Air travel, on the other had, offers a grander view of nature's handiwork (clear skies permitting) and yesterday's route was perfect for observing the chalk lands of Kansas.
