332 
HUBBARD AND CRONEIS 
to the Birdseye (Lowville) limestone of New York and its equiva- 
lent, the Tyrone formation of Kentucky. The Hermitage and 
Bigby formations of Tennessee are also closely related to the 
upper Chickamauga of Giles County. 
The Chickamauga Formation Subdivided 
Section along the Narrows of the New River in the Virginian 
Railroad cut. 
1. A coarse chert breccia, with fragments of non-crystal- 
line limestone in a crystalline matrix. The chert fragments are 
two to fifteen inches in their longest dimension, are angular, and 
lie in all positions in reference to the bedding plane, often being 
in contact and sometimes in apparent layers. No calcite veins. 
3 to 10 feet. 
The chert in the breccia mentioned above is identical with the 
fragments which weather out of the Shenandoah today. 
2. Two layers of fine chert breccia, the fragments being two 
inches or less in their greatest dimension. Fragments are rarely 
in contact, nor are they in distinct beds, but are scattered 
throughout the somewhat crystalline matrix. A normal fault 
of 2 feet cuts across these two horizons. 6 feet. 
3. A finer grained chert breccia, the fragments being from 
one inch in their greatest dimension down to the most minute, 
but it is clearly a breccia, for the fragments occur in great num- 
bers and lie in all positions. Quantities of these are collected at 
various intervals into beds, the fragments becoming smaller and 
fewer upwards, but they end abruptly near the top. The matrix 
is a fine grained, gray limestone in layers of four inches to four 
feet. No calcite veins, looks like the Shenandoah. 45 feet. 
4. A partly covered interval. Fine grained, light colored, 
medium bedded limestone with some shale partings. The calcite- 
veined chert extends to the base. The limestone beds are dove 
colored to dark blue and often have dark chert nodules, which 
sometimes are arranged in beds. There is some calcite veining 
in the chert. Toward the top of the section dark blue chert pre- 
dominates with light colors more characteristic of the lower 
layers. There are open joints and bedding planes, and the usual 
weathered or water-rounded forms so characteristic of this 
formation. 243 feet. 
