THE PALEOECOLOGY AND ECHINODERM FAUNAS OF THE LOWER PENNINGTON IN SOUTH-
CENTRAL KENTUCKY
CHESNUT, Donald R., and ETTENSOHN, Frank R., Department of Geology,
University of Kentucky, Lexington, Kentucky 40506

Echinoderms collected from the upper Glen Dean of south-central Kentucky 
have been well-known since the early 1900's. Many of the localities have 
become world-renowned, paIticularly the old Southern Railroad
cut at Sloan's Valley, Kentucky. New collections from these and other 
localities have yielded over 450 well-preserved echinoderm specimens,
belonging to 50 different species. Crinoids, blastioids, echinoids,
ophuiroids, asteroids, and edioasteroids are represented in the fauna.
The diverse, populous faunas of this unit also contain numerous brachiopods, 
bryozoans, pelecypods, gastropods, and rugosans.
	Reevaluation of the stratigraphy indicates that rocks previously
called upper Glen Dean are in fact, parts of the lower Pennington Formation. 
The Glen Dean is a massive, crossbedded skeletal calcarenite
which is locally oolitic; it contains a sparse, thick-shelled fauna.
The lower part of the Pennington intertongues with the Glen Dean and
consists of dark shale with interbedded calcarenite lenses; it contains
a diverse fauna with many delicate, benthonic forms. Most of this fauna
is associated with the limestone lenses.
	The Glen Dean is interpreted to represent a shallow, high-energy
carbonate sand belt of migrating shoals. Overlying parts of the lower
Pennington are interpreted to represent a somewhat deeper, protected
lagoonal environment leeward of the sand belt. The limestone lenses on
which most of the echinoderms occur appear to represent isolated shoals
in the lagoon, probably derived as spillover lobes from the sand belt.
The firm substrates provided by these shoals, as well as their protected
position leeward of the sand belt, seem to have provided optimal environmental 
conditions for the proliferation of echinoderm faunas.