Kansas Geological Survey, Subsurface Geology 12, p. 83-84
by
J. M. Cocke1 and A. P. Bennison2
1Central Missouri State University
2Consultant, Tulsa
Corals of the supposedly coeval Sageeyah and Wimer School limestones and accompanying stratigraphic modeling indicate that these strata accumulated at different times in geogaphically separated areas on the Chautauqua platform. Although both limestones are similar in being dominantly irregularly bedded, brown to gay, algal-lime mudstones to wackestones within the upper Labette Shale, their physical connection in surface outcrops is controversial.
The Sageeyah Limestone is about 20 m (66 ft) thick in the vicinity of its type locality in Rogers County, but northward in Nowata County it thins to less than 0.5 m (1.7 ft) of tidal to subtidal limestones where it is locally truncated by the Childers School Limestone (the basal transgressive member of the Pawnee Limestone), which locally overlies the Lexington coal bed and underclay. About 8-20 m (26-66 ft) stratigraphically below the Pawnee Limestone are outcrops of Wimer School Limestone as much as 2 m (7 ft) thick in Nowata County, but generally less than 1 m (3.3 ft) thick northward in labette County. Southward, in northernmost Rogers County, stratigraphic modeling indicates that both the Wimer School and Sageeyah limestones are missing because of probable truncation over an east-west-trending pre-Pawnee anticlinal uplift that exceeds 20 m (66 ft) in amplitude and is about 22 km (13 mi) wide.
The Sageeyah Limestone is composed of fossilferous lime mudstones to wackestones, relatively barren siliceous mudstones, and crinoidal grainstones with local interbeds of shallow marine to onshore siliciclastics. Such variations indicate an unstable shelf environment of considerable bathymetric relief prior to the erosional event preceding Pawnee Limestone deposition. Such renewed marine transgressions served to introduce new coral populations on the Chautauqua shelf and proves their value as supplemental chronostratigraphic markers.
Unlike most Middle Pennsylvanian carbonate banks on the Chautauqua platform, the Sageeyah and Wimer School limestones lack anoxic core shales. Both the Wimer School and the Sageeyah limestones contain the shallow water Lophamplexus-Amandophyllum Coral Assemblage that, with abundant algae and other invertebrates, characterizes parts of the transgressive, regressive, and transgressive-regressive limestones of Missourian and Virgilian units. The assemblage is not clearly recognized in the Morrowan and Atokan.
The corals of the units studied differ considerably at the species level, supporting evidence that the Sageeyah Limestone is younger than the Wimer School Limestone which was deposited somewhat more distally on the Chautauqua platform. Amandophyllum has four species (three--Wimer School; one--Sageeyah). The genus is most common to the intermediate- to shallow-water regressive and transgressive-regressive limestones. A single species of Sestrophyllum occurs in each of the units studied. Sestrophyllum is most common in the deeper water regressive, transgressive, transgressive-regressive limestones but is the most common dissepimental genus in transgressive lime- stones. A species of Orygmophyllum occurs in Sageeyah. The genus typically occurs in the moderate- to shallow-water limestones in regressive and transgressive carbonates. The Sageeyah caninoid bothrophyllids are represented by two species, one of which is nonfossulate with a weak columella, the other species has the typical bothrophyllid characters of 1) long major septa, 2) a columella that is either a rhopoloid structure or a fusion of major septal ends, and 3) a persistent cardinal fossula. A single Wimer School species is generally similar but is clearly a different species. The Middle and Upper Pennsylvanian caniniids-including the bothrophyllids--occur in moderately deep- to shallow-water regressive and transgressive-regressive limestones.
Figure 1--Schematic stratigraphic section of the Wimer School to Altamont Limestone Banks and associated strata in northeast Oklahoma; datum is base of Pawnee Limestone (Childers School Limestone Member).
Kansas Geological Survey
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Web version May 12, 2010. Original publication date 1989.
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