STRATIGRAPHY OF MOHAWK VALLEY AND SARATOGA CO. 481 
Feet 
B? Drab colored stratum similar in lithologic ap- 
pearance to the Birdseye. 2=-28+ 
B* Massive dark gray limestone forming the 
floor of the quarry. This stratum contains numer- 
ous specimens of Columnaria alveolata 
Goldf. and Buthotrephis succulens Hall 
which are specially well shown. I==2094 
B® Dark blue rather thin bedded limestone thicken- 
ing toward the western end of the quarry. It is not, 
however, used for “marble” but burned for quick- 
lime as is some of the rock from the next zone. 3, 5=—365 
B® Massive, fine grained, dark gray, compact lime- 
stone, the “black marble” of the quarrymen. This 
zone which is in the Trenton limestone divides into 
three beds; the lower massive one 4 feet, 3 inches in 
thickness, the middle massive one 5 feet, 6 inches and 
the upper one composed of three thin layers 3 feet 2 
inches. 123456 
B’ Thin shaly limestones extending to the top of 
the quarry. 123581 
The dark gray compact limestone of zone B® when sawed is 
capable of taking quite a polish and this has suggested the name of 
marble. The characters of the Black river and Birdseye subforma- 
tions appear to be so blended in this quarry that it becomes diffi- 
cult to separate them. The following section was measured on the 
south bank of the Hudson river immediately below the street bridge 
between Glens Falls and South Glens Falls: 
Feet 
54A1 Drab colored limestone with vertical mark- 
ings like Phytopsis tubulosa Hall. 11 in- 
ches measured at the water’s edge and possibly 1 
foot in thickness. The rock is very compact and fine 
grained but darker in color than the Birdseye lime- 
stone in the Mohawk valley though it weathers to a 
similar light gray color. The equivalent of zone B® 
on the north bank. II 
A? Dark gray to bluish, lumpy limestone contain- 
ing Columnaria alveolata Goldf, Strep- 
telasma and some other fossils as well as black 
