108 TRANSACTIONS OF THE [FrEs. 23 
other portions of the western Adirondack region. A second 
contribution on the petrography of the region will shortly 
follow. 
Hamitton Corzece, Clinton, N. Y. 
ON PHOSPHATE NODULES FROM THE CAMBRIAN OF 
SOUTHERN NEW BRUNSWICK. 
BY W. D. MATTHEW, 
Inrropuction.—Nodules and beds of phosphatic material are 
best known in the Cretaceous and Tertiary formations, but they 
also occur in many places in strata of Cambrian and Silurian 
age. The deposits of these older rocks are sometimes of economic 
importance, and are always interesting, both on account of the 
various theories of their origin, and because they are generally 
considered as due, directly or indirectly, to organic life. 
To account for the little changed phosphate deposits of the 
Cretaceous and Tertiary, has proven a matter of no small 
difficulty, and many hypotheses, more or less plausible, have at 
different times been advanced. With the older deposits there 
is even greater difficulty, because they are usually so altered 
that their original structure is pretty well obliterated. 
Division oF THE Sart Jonn Grour.—Those described here are 
from the St. John Group of Southern New Brunswick, a series 
of gray slates, shales, and sandstones, mostly of Cambrian age, 
which formerly filled the bottoms of a number of long, parallel, 
northeast and southwest valleys, but which have been mostly 
swept away or covered by later deposits, except in the southern 
one, near the western end of which the city of Saint John is 
situated. The St. John Group is divided as follows : 
DIVISION 1, OR ACADIAN STAGE, 
. Coarse gray sandstone or quartzite. 
. Coarse gray sandy shale. 
. Fine gray and dark gray shales. 
. Fine dark gray carbonaceous shales. 
aoce 
DIVISION 2, OR JOHANNIAN STAGE. 
a. Coarse gray slates with thin seams of gray sandstone. 
b. Coarse gray slate and gray flagstone, the latter 
predominating. 
c. Gray flagstone and gray slate, in frequent alternations. 
