20 TRANSACTIONS OF THE [ocr, 24, 
the following formations : 1. The Primary, embracing granite 
(7. e., labradorite rock) and gneiss. 2. The Transition (7. e., 
Cambro-silurian). 3, The Tertiary or newer Pliocene. (7. e., the 
glacial clays, etc.). Emmons makes an extended argument to 
prove the igneous character of certain limestones, and in the 
report on the first district, Mather corroborates the idea. 
‘Emmons’ second report contains also many details about iron 
mines, and an account of his ascent of Mt. Marey, which he 
determined to be 5,467 ft. 
The third annual report (1839) describes Hamilton, Clinton 
and Warren Counties, but is mostly devoted to the discussion of 
various economic minerals, peat, marl, ete. The fourth report, 
1840-41, takes up the iron ores at length, especially those at 
Lake Henderson. 
The final report appeared in 1842. The classification of for- 
mations is as follows: 
A—Primary. 
I. Unstratified. 
a. Granite. 
b. Hypersthene rock. 
c. Primitive limestone, 
d. Serpentine. 
e. Rensselaerite. 
II. Stratified. 
a. Gneiss. 
b, Hornblende (7. e., hornblendic-gneiss. ) 
ce. Sienite. 
d. Tale or Steatite. 
Ill. Subordinate. 
a. Porphyry. 
b. Trap. 
c. Magnetic and 
d. Specular oxide of iron. s 
B—New York Transition System. 
ines si5 Group. 
a. Potsdam sandstone. 
b. Calciferous sandrock. 
c, Chazy limestone. 
d. Birdseye limestone. 
e. Trenton limestone. 
J. Utica slate. 
g. Lorraine shales. 
h. Grey sandstone. 
C—Tertiary. 
