GEOLOGY OF GILES COUNTY, VIRGINIA 
353 
2. Rather even bedded sandstone and coarse but even grained 
sands well cemented with iron oxide. Many molds of pelecypods 
in the main poorly preserved. 20 feet ±; 
3. Limestone and chert. Whole beds are of chert, others are 
a chert breccia with a meagre limestone matrix. In no place was 
number 4 present with number 3 eroded away. Fossils were 
found in the chert only. The colors are red, tan, pink, yellow 
and gray. The bedding is irregular to imperfect. 
40 feet ±: 
4. Coarse yellow, buff, tan and green sandstones in part 
loosely cemented, in part almost quartzite (boulders travel long 
distances in the float). Many molds of Spirifer mucronatus, 
with hinge line much extended and a few S. arenosus. Some of 
the beds are shaley but the member is for the most part sand- 
stone. 100 feet ± 
These four members were found together in two or three 
places and one or more of them were recognized repeatedly but 
they never could be traced far. They became covered with their 
own waste or float from the Rockwood. Nevertheless the group 
as a single map unit was placed on the map almost all the way 
from the river west to the county line. The area varies greatly 
in width because in many places the greater part of the Giles has 
. been eroded away from the Rockwood. 
It seems reasonable to correlate No. 1 with Coeymans, No. 2 
with New Scotland, No. 3 with Becraft and No. 4 with Oriskany, 
but any such allocation is only tentative. No. 4 and Oriskany are 
the most confidently connected. There is much less assurance 
concerning the other three. 
There seems to be an unconformity at the base of the Oriskany, 
but the details of the occurrence or absence of different parts of 
the Cayuga and Helderberg are not well known in this area. 
It seems to the writers that future work here will justify a revi- 
sion of the nomenclature of the lower Devonian which may re- 
sult in at least three new division names for rocks which are at 
present simply called Giles. 
The Romney Shale 
Overlying the Giles, there are in a few places in Giles County, 
dark shales to which the name Romney has been given. These 
shales grade insensibly from black carbonaceous shale, which is 
