TULLY LIMESTONE. 
213 
The illustration at the head of the preceding page is from a sketch on the shore of Seneca 
lake, south of Hathaway’s landing, where the Tully limestone is seen to dip from the north, 
and pass beneath the level of the lake ; and again a few rods farther on, it rises from beneath 
the water and ascends southward, disappearing from the shore. About six miles farther south, 
it again comes to the level of the lake, and disappears beneath it for the last time. 
These undulations appear upon ihc west side also, and here it makes another ascent from 
the lake after its second disappearance beneath it. This place is a short distance south of 
Bigstream point, in Yates county. It is merely the top of the arch which appears above the 
water, presenting its whole thickness with a few feet of the shale below, and curving gra¬ 
dually downwards in either direction. (See woodcut 91.) 
On the eastern shore of Seneca lake, where this rock rises considerably above the water 
level, the action of the waves has undermined the softer shale beneath, and leaves the lime¬ 
stone projecting. This process has evidently gone on for a long period, as the shore is skirted 
by an irregular wall of the fallen fragments. Thousands of tons of these fragments have been 
removed for burning to lime, and those now remaining are mostly beneath water. The practice 
of removing these fragments, or of allowing them to be taken away, is of doubtful economy ; 
for while they remain, they form a barrier which protects the shore from farther encroachments 
by the water; but their removal admits a renewed action of the water upon the cliffs, which 
undermines the limestone, bringing it down with all the mass above it. 
Along the western shores of the lakes this feature is not perceptible, from the short duration 
of easterly winds, which have little influence upon the shales. The high perpendicular cliffs 
are consequently less common on this side, and the limestone less exposed. 
This limestone appears in the banks of the outlet of Crooked lake, being visible almost 
continuously from Seneca lake as far as the fall at Wait’s mill on the outlet, where it dis¬ 
appears beneath the superincumbent black slate. 
After leaving this place and the western shore of Seneca lake, this limestone appears but at 
few points farther west. In the bed of Flint creek, at the village of Bethel, it is visible, and 
at another point about four miles northwest of this place, in the bed of a small stream. At 
the latter point, it is but three feet thick. 
A few miles farther west, on Canandaigua lake, it is represented by a few inches of im¬ 
pure calcareous matter, but the character of the shales above and below contrast as strongly 
as where the limestone has its greatest thickness. In all localities west of this point, where 
the junction of the shales can be examined, we find a few inches of hard impure limestone, 
which would scarcely be noticed but for the contrast in the shales, which bear the same cha¬ 
racters as farther east. 
So far, therefore, as it can be described, this rock is virtually absent at all places west of 
Canandaigua lake; still its place is equally marked, and affords a point of reference in all 
localities. Its origin was evidently at the east, and from the small quantity of the product, it 
has spread over only a small portion of the State. Were it not for the great contrast in the 
shale above, and the extinction of the greater part of the organic remains at this point, it might 
be united with the last group, being in fact less persistent than the Encrinal limestone which 
