ABSTRACT: The Cretaceous Rocks of Kansas
P. Allen MacFarlane, Vincent J. Hamilton
Cretaceous strata are well represented in the central and western portions of Kansas and record a sequence of events that spans much of the Cretaceous Period (Albian to Campanian age). Cretaceous strata are grouped into Upper and Lower Cretaceous Series marine to nonmarine fine to coarse-grained clastics, chalks and chalky limestone. Bentonite beds, thin coals, and lignites are also represented. The Cretaceous formations recognized in Kansas are the Pierre Shale, Niobrara Chalk, Carlile Shale, Greenhorn Limestone, Graneros Shale, Dakota Formation, Kiowa Formation, and Cheyenne Sandstone. Major unconformities separate Cretaceous from Jurassic, Permian, Tertiary, and Quaternary deposits. Regionally significant unconformities within Cretaceous strata separate the Kiowa-Dakot Formations, the J-D sandstone members of the Dakota Formation, the Graneros Shale-Greenhorn Limestone, and the Carlile Shale-Niobrara Chalk. Seaward shifts in facies, evidence of subaerial exposure, and incomplete facies successions are the basis for recognizing three unconformity-bounded sequences--Cheyenne, J, and D--on the eastern margin of the Cretaceous Western Interior basin in Kansas. The basal unconformities of these three sequences are equivalent to the unconformities at the bases of the Plainview Formation, J sandstone, and D sandstone in Colorado.
AAPG Search and Discovery Article #91002©1990 AAPG Rocky Mountain Section Meeting, Denver, Colorado, September 16-19, 1990