314 
[Assembly 
The group succeeding the black shale occupies the towns of Naples 
Canadice, and the south part of Bristol, and presents the same essen- 
tial characters as described in Seneca county. Alternations of compact 
shale and argillaceous sandstone compose the group. The sandstone 
portions are used for flagging stones, and when sufficiently thick, for 
building stones. 
These rocks are seen to great advantage in the deep ravines about the 
head of Canandaigua lake and in the banks of the Honeyoye, Canadice 
and Hemlock lakes. These three lakes at present join their outlets, 
producing the Honeyoye creek, which has been excavated since the de- 
position of the alluvium; and the rocks are exposed along its whole 
course. The original outlet of these valleys was probably farther east, 
and joining the present Irondequoit, passed into Lake Ontario by that 
channel. These valleys also extend south, and meet the Conhocton, 
showing that at some former period the course of the water was not re- 
stricted within its present limits, but extended south to the Tioga or 
Chemung. Thus a stream whose width embraces the valleys and beds 
of the lakes in this direction, may have passed southward from Lake 
Ontario to the Susquehannah; or, otherwis?, a stream from the south 
may have flowed along the Conhocton and these valleys to Lake Onta- 
rio. It is quite evident, from the extent of the valleys and the alluvi- 
um piled up in their course, that few of our streams in an earlier geo 
logical era had their present origin, or were limited to their present ex- 
tent. Every valley and every rock bears marks of the great current, of 
which small under currents merely wore the course of the present val- 
leys, while the mighty whole passed over the hiczhest points of our hills. 
YATES. 
The rocks of the greater part of Yates county correspond with those 
of the southern portion of Ontario, and only the most elevated parts of 
the towns of Barrington and Starkey contain other rocks. 
The black shale above the Tully limestone, occupies the north part 
of the towns of Middlesex and Benton, the southeastern part also of 
the latter exhibiting this shale and the rocks below; the superior rocks 
having been removed over that part of the country east of a line drawn 
from Penn-Yan to Seneca lake, near Bellona. The outlet of Crooked 
lake, now narrowed to a small stream, once flowed northeast along the 
valley from Penn-Yan, nearly in the direction of the east branch con- 
tinued. 
