Algal-Bank Complex in Wyandotte Limestone (Late Pennsylvanian) in Eastern Kansas

Abstract

The Wyandotte Limestone is divided into seven lithologically and paleontologically distinct facies:

1. a terrigenous facies--mostly unfossiliferous, silty shale, and quartz sandstone;
2. a stromatolite-sponge facies--a sponge-bearing stromatolitic biolithite;
3. an algal-bank facies--a phylloid algal biomicrite, dismicrite, and intrasparrudite;
4. an Archaeolithophyllum cap facies--a phylloid algal biolithite that capped the algal banks;
5. a calcarenite facies-biosparite, intrasparite, and Osagia-coated biosparrudite;
6. an oolite facies--oosparite and oomicrite; and,
7. a shelly mud facies--a crinoidal, brachiopodal biomicrite.

The basic factors controlling these facies were geometry and hydrography of the basin of deposition. A platform on the Lane Shale controlled initial carbonate facies development. This was subsequently modified by changes in water circulation and turbulence, the more immediate controlling factors of carbonate facies. Nature of the substrate, salinity variation, water energy, and amount of water circulation were the chief limiting factors in distribution and abundance of the Wyandotte biota.

Calcareous phylloid algae of the genera Archaeolithophyllum and Anchicodium played an important role in intertidal to shallow subtidal bank development. Archaeolithophyllum was abundant in sediments deposited in more turbulent water that was perhaps slightly shallower than the environment where Anchicodium thrived. The latter genus served as a baffle, allowing fine carbonate mud to settle out, while in both genera mud was trapped and bound beneath the blades. This produced the banks which provided a well lighted, shallow-water habitat for further prolific algal growth.