Elwood Atherton, Charles Collinson, and Jerry A. Lineback
The Hombergian Stage (Swann, 1963, p. 22, 70), the middle stage of the Chesterian Series, derived from the Homberg Group (J. M. Weller, 1939), is named for Homberg, Pope County.
The Hombergian Stage includes strata from the top of the Beech Creek up to the top of the Glen Dean (fig. M-25). The limestones in this stage are typically light brownish gray, light gray, or buff to gray and many of them and their associated shales are abundantly fossiliferous. Red shales in the upper part of the Fraileys and the lower part of the Hardinsburg are extensive marker beds.
The bryozoan Prismopora serrulata and the crinoid Pterotocrinus (fig. M-4) are typical Hombergian fossils.
SWANN, D. H., 1963, Classification of Genevievian and Chesterian (Late Mississippian) rocks of Illinois: Illinois State Geological Survey Report of Investigations 216, 91 p.
WELLER, J. M., 1939, Mississippian System: Kansas Geological Society Guidebook, 13th Annual Field Conference, southwestern Illinois and southeastern Missouri, p. 131-137.
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