Joe Clair noted in a 1948 Kansas Geological Society report, that the Mississippian (Miss.) was "for many years, to the majority of Kansas Geologists ... a top and base with varying thickness of very hard rock between". Ed Goebel's dissertation (1966) study of cores, samples, and microfossils was a major contribution to Miss. stratigraphy in western Kansas. The Kansas Sample Log Service (primarily J.D. Davies) lithologic strip logs also provide a wealth of rock descriptions and subdivisions of the Miss. Many geologists and companies, still following the fifty-year-old remark of Clair, often drill only the top portion of the Miss. and report "Miss." (literally period, with no reference to subdivisions).
Continued petroleum exploration in the Hugoton Embayment has provided a wealth of new geophysical logs. Regretfully, Miss. rotary drilling samples are often of poor quality from severe caving of overlying units. Up to date, preliminary research of all wells penetrating the complete Miss. section has been made. Log sections and maps prepared from this study give a scattered sample of Miss. subdivisions and correlations.
The distinct massive, "clean", oolitic limestone
of the Gilmore City formation is one of the best correlation markers.
Reservoir development related to Salem (Spergen) anhydrite dissolution
is illustrated. Various unresolved stratigraphic problems, such
as the distribution of Chesterian rocks, Ste. Genevieve - St.
Louis boundary, and St. Louis oolite reservoir zones are also
illustrated. As the exploration history of this area has proven,
resolution of difficult Miss. geology correlations will result
in new hydrocarbon discoveries for many more years.