ii8 
The American Geologist. 
The New York Series. 
February. 1900 
Era or System 
Period or Group 
Age or Stage 
Cambric or 
Taconic 
r Georgian 
< Acadian 
l^ Potsdamian 
Georgia slates. 
Potsdam sandstone and lime- 
stone. 
Champlain- 
ic(i) 
(Lower 
Silurian and 
Ordovician) 
{ Canadian (3) \ Beekmantown limestone (15) 
(Paleochamplainic) '{ Chazy limestone 
Mohawkian (4) 
(Mesochamplainic) 
t Lowville limestone (16) 
•] Black river limestone 
( Trenton limestone 
Cincinnatian (5) \ 
Utica shale 
I (Neochamplainic) j Lorraine beds (17) 
( Richmond beds (Ohio and 
Indiana] 
\ Oswegan (6) 
I (Paleontaric) 
Ontaric (2) 
or J Niagaran(7) 
., . I (Mesontaric) 
Silunc 1 
I Cayugan (8) 
I (Neontaric) 
C r 
5 Helderbergian (9) 
^ I Oriskanian (10) 
g f Ulsterian (11) 
Devonic -^ 
^ I Erian(i2) 
Senecan (13) 
> 
i 
Oneida conglomerate 
Shawangunk grit 
Medina sandstone 
f Clinton beds 
Rochester shale 
Lockport limestone 
[Guelph dolomite 
Salina beds 
Rondout waterlime (18) 
Manlius limestone (19) 
I Coeymans limestone (20) 
J New .Scotland beds (21) 
I Becraft limestone (22) 
t Kingston beds (23) 
Oriskany beds 
I Esopus grit (24) 
\ Schoharie grit 
( Onondaga limestone 
Marcellus shale 
Hamilton beds 
r Tully limestone 
I Genesee shale 
I Portage beds 
(Naples beds, 
Ithaca beds, 
Oneonta beds, 
local facies) 
Chautaiuiuan (141 \ 
Chemung beds 
(Catskill sandstone, (25) 
local facies) 
