352 
HUBBARD AND CRONEIS 
Limestones to limey shales, to black shales, grading at last to 
sandstones at the top, constitute the normal succession of Devon- 
ian strata in Giles County. 
The Giles Formation 
Above the Rockwood is a group of strata of diverse charac- 
teristics, but hard to separate in the field. In the Kimberling 
Creek area, in the western portion of the county, there is at the 
base of the Giles some forty feet of blue limestone, calcareous 
shale at the base but heavy limestone at the top. This is followed 
by coarse, ferruginous sandstone, some fifteen feet in thickness, 
made up of small quartz pebbles. Above this, there is cherty 
limestone, about thirty-five feet thick, which is always present 
along the outcrop and is the key to the subjacent strata, and fol- 
lowing this, there is an undetermined thickness (probably less 
than 100 feet) of yellow-green sandstones.^^ 
Paleontology and Correlation 
Little time was spent on the fauna of the Devonian formation. 
The upper divisions of the Giles are Oriskany and Helderbergian 
in age, but the two lower divisions, as described above are with- 
out faunal record in Giles County. On the south slope of East 
River Mountain, between Narrows and the west county line, 
there are many exposures of the beds grouped as Giles. They 
are cut somewhat parallel to Wolf Creek by a fault so that their 
resistant layers repeat in places to form several rocky ridges. 
Farther west in Wolf Creek Valley and quite near the county 
line the Giles outcrops in two strips with Rockwood above the 
northern strip and again between the strips, while Shenandoah 
appears to the south. A fault has let the Giles down against the 
Rockwood, thus preserving it. Erosion has removed the Giles 
from a part of the Rockwood farther down the slope and a large 
fault near Wolf Creek has carried the Shenandoah up to the 
height of the Giles. In these areas considerable detailed work 
has been possible, and the following correlations have provision- 
ally been made : 
1. Blue calcareous beds varying from firm limestones toward 
the top to weak shales at the base, and resting immediately on 
the Rockwood. 40 feet ± 
Campbell, M. R., U. S. G. S. Folio No. 26. 
