Bides and 3I/sriiIes /» Classifirdtion. — Marcov. 
121 
S. 
R. 
Q- 
p. 
o. 
N. 
M. 
L. 
K. 
I. 
Kr. 
Ju. 
C. 
Del 
1894. 
Sedimentary rocJcH. 
Cretaceous. 
Jura-Trias. 
Carboniferous. 
. Catskill. 
m 
Dpt. 
Dhm 
Don. 
Dor. 
Sh. 
Ssl. 
Sng. 
Scl. 
Sni. 
Shr. 
i .5 
and geological map was kept away from the public until 1877, 
and even until 1885) ,and 1894: (practically issued in 1896). I 
give below the "legends:" 
1842. 1844. 
Alliivial (no color, but signs) ^ & 
m 4.- { Sand Tjlains. ;]^ -^ 
Tertiary j(.i^y/ | | 
Trap rock. .5 r^ 
New red sandstone. ^' | Del. Catskill. 1 
Catskill Mt. rock. 
Portage and Chemung. 
Hamilton. 
Helderberg series. 
Onondaga Salt group. 
Niagara. 
Clinton. 
H. Medina sandstone. 
G. Gray sandstone and 
Shavvangunk grit. 
Hudson River group or 
Lorraine shales. 
Utica slate. 
Black River and 
Birdseye limestone. 
C. Calciferous sand rock. 
B. Potsdam sandstone. 
JU 
O 
P 
;h 
O 
~i-i 
>H 
_c 
& 
cc 
Oj 
^ 
A. Primary system. 
O % 
3 «2 .::i 
Dch. Chemung. 
Do. Oneonta. 
Portage. 
Hamilton. 
Onondaga. 
Oriskany. 
Helderberg. 
Salina. 
Niagara. 
Clinton. 
Medina and 
Oneida. 
Hudson and 
Utica. 
Shrm. Metamorphic 
Hudson. 
Str. Trenton. 
Strm. Metamorphic 
Trenton and 
Calcifei'ous. 
Calciferous. 
Potsdam 
J 
f Cambrian 
iJD 
<f1 
Scf. 
Cp. 
Cg. Georgia. \ 
Younger igneous rocks. 
Ancient crystalline rocks, 
5 rd divided in six groups. 
The western, or fourth district, as well as the central por- 
tion, or third district, are the easy part of the work; the for- 
mations and beds following one another with the regularity of 
tiles upon a roof, or steps on a staircase, without any ditiicul- 
ty of succession, of disturbance or faulting. For that part 
of the map, all that was required, to make it more exact, was 
to mark the limits of each group or formation with more ac- 
curacy, and to add some details in the classification of some 
of the great and important groups like the Chemung and 
Portage, where a new division has been introduced between 
