Abstract

Thick, calcium-carbonate bank deposits are found in the Lansing-Kansas City Groups (Pennsylvanian) of the Hugoton Embayment in southwestern Kansas. Oolites and other calcarenites were deposited in shallow, high-energy environments overlying preexisting carbonate mounds. Some evidence indicates that the mounds are of organic origin (probably algae). The occurence of oil or gas production is related to thick accumulation of calcarenite (carbonate shoals) which is coincident with structural highs.

Mounds had very little, if any, influence on the surrounding depositional environments; therefore, no off-bank facies can be identified. The location of mounds has no apparent correlation with any preexisting structure.

There is a good correlation between thickness of individual zones and lithology. Shallow-water micrites occupy the thin areas, whereas the shoal facies are confined to areas which are often two or three times thicker. The areal size of the banks varies from a few hundred feet to two or three miles in width. Length also varies up to five or six miles.