MARINE TRANSGRESSIONS IN THE CENTRAL APPALACHIAN BASIN DURING THE
PENNSYLVANIAN PERIOD
CHESNUT, Donald R., Jr., Kentucky Geological Survey, 228 Mining
and Mineral Resources Bldg., University of Kentucky, Lexington,
KY 40506-0107

Compilation of paleontological data from Pennsylvanian rocks from the
Central Appalachian Basin reveals that marine and brackish strata
overlie the major coal beds. The extensive nature of marine strata and
major coal beds, and the repetitive sequences of coal-bearing strata
with a 0.43 ma periodicity support eustatic control for these marine
transgressions.
	Mapping of biofacies of the marine strata shows that during the
Early Pennsylvanian, the marine source was to the south or southwest.
Stratigraphic analysis of Early Pennsylvanian rocks indicates that
these foreland basin deposits onlapped toward the forebulge, but did
not crest it. Biofacies mapping of Middle Pennsylvanian strata shows a
southern and western source for marine conditions. The forebulge was
probably crested at times, especially along saddles such as the
Cumberland Saddle. Hingelines at the southern end of the Rome Trough
and at the Kentucky River Fault System, both of which subsided to the
south, may have caused deeper marine conditions in the southeastern
part of the basin. Geologic studies indicate marine sources to the
north or northwest for late Middle and Late Pennsylvanian time.
	During the Early Pennsylvanian, marine waters from the Ouachita
Trough transgressed through the underfilled Ouachita and Appalachian
foreland basins. Forebulges of these systems were not breached.
During the Middle Pennsylvanian the basins were alternately filled and
underfilled, and at times the forebulges were breached along saddles.
Marine transgression proceeded through the subsiding part of the
foreland basin and through saddles. During the late Middle and Late
Pennsylvanian, the Ouachita Basin was deformed, closing off access for
marine transgression through the southern foreland basins. Marine
waters apparently transgressed through the Illinois Basin, through
Ohio, north of the Jessamine Dome, to the Dunkard Basin.