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HUBBARD AND CRONEIS 
The Moccasin Limestone 
The Moccasin Limestone, correlated with the Athens Shale 
and the Tellico Sandstone of Eastern Tennessee, marks, the 
transition from the hard blue limestone of the Chickamauga to 
the Sevier calcareous shales. The formation is composed of red 
and greenish blue earthy limestones having a mottled appear- 
ance, and always weathering with a characteristic hackly appear- 
ance. These limestones usually outcrop on the steep slopes of 
the valley ridges and thus give a pronounced color to the land- 
scape. The formation occupies a position stratigraphically in- 
termediate between the great limestones beneath and the shales 
and sandstones above. The exposed surfaces are often ripple 
marked or mud cracked, indicating that the seas were much shal- 
lower than before and at their minimum depth for a limestone 
to be formed. 
These limestones take their name from Moccasin Creek, Scott 
County, Virginia. In thickness, they vary from 300 to 500 feet, 
being 344 feet thick at the Narrows. There are several layers 
which are of proper texture and composition to have value a« 
lithographic limestones but are too thin and fragmented. They 
have been tried as such by the U. S. G. S. Towards the top of 
the formation, there are alternate limestone and shale beds in 
which the limestone is gray blue, resistant with a hackly fracture 
and splintering into fragments because the jointing is not at 
right angles to the bedding plane. The shale horizons are very 
weak, the red and yellow beds weathering rapidly into very sticky 
clays. The entire formation exhibits the splintery fracture de- 
scribed above. Calcite veining oecurs, but is not a dominant 
feature. 
Paleontology and Correlation 
For some time, the Moccasin limestone has been regarded as a 
transition formation between the great development of Ordovi- 
cian limestones in the Powell valley and the equally great de- 
velopment of shale and sandstone in the eastern portion of the 
Appalachian Valley. If this were the case, and continuous ex- 
posures could be had, the formation should grade into lime on 
the west and shale in the east. Recent investigations show that 
this is not the case and that the Moccasin is but a single Ordovi- 
