GEOLOGY OF GILES COUNTY, VIRGINIA 
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bachii, Liocalymene clintoni, Beyrichia lata. This array of forms 
establishes the Clinton age for the Rockwood, and suggests that 
the lower Rockwood is the equivalent of the middle or upper 
Clinton of New York. 120 feet. 
2. Dense, quartzitic sandstone in three or four layers, one of 
which is about 18 inches thick. The sandstone is coarse grained 
at the base. 3 feet. 
3. Ferruginous shales and sandstones in alternate beds. The 
average color of the sandstones is red. The shales are thin, gray 
and green. 18 feet. 
4. Dark red, ferruginous, quartzitic sandstone, irregularly 
bedded and jointed. Weathers to a rusty brownish red. Irregu- 
lar blocks as large as five feet thick weather out. Hematite in 
certain places. 5 feet. 
5. Alternating sandstones and shales. The sandstones are 
two to five inches thick and are red and grey, dense and quart- 
zitic. Regular cuboidal jointing into brick like blocks. Thin 
shale beds of a smooth greenish gray color and not sandy. 
Bryozoans are common. Fucoids? 6 feet. 
Section described now goes to Virginian cut. 
6. Shales, having soapy feel, without grit. Gray, green and 
yellow, weathering soft, punky almost black. Thinly laminated. 
Brachiopods. 13 feet, 
7. Layers of blue, gray, and pink, dense quartzitic sandstone, 
with a little shelly material in the upper half. Weathers a dark 
brown and red. Atrypa reticulaias. 6 feet. 
8. Coarse buff sandstone, not cemented and not quartzitic 
with ferruginous veins with crooked branching, which seem to 
be impregnation of the natural pore spaces between the grains 
of sand. Iron is more abundant and much darker red than usual 
in this division. There are many cavities an inch or less across. 
The rock is thin bedded but one layer in the middle part is 2 — 
21/2 feet thick. Possible bryozoans were found. 7 feet. 
9. Gray sandstone, with fine gray blue shale layers. The 
sandstone is quartzitic in beds of two to eight inches. One group 
seems to be a heavy one but shows thin when weathered. Near 
the bottom several layers are a pronounced red and weather 
rusty. Strong cross bedding. No fossils. 15 feet. 
10. Black, carbonaceous, shaly layers, as well as red, brown 
and gray ferruginous layers. It is always sandy with quartz 
