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1894. | NEW YORK ACADEMY OF SCIENCES. 21 
INTRODUCTION AND GENERAL FEATURES: FORMATIONS 
REPRESENTED. 
Under direction of Prof. J. F. Kemp and in connection with 
the summer field-work of the geological department of the 
School of Mines, Columbia College,* the writer spent the 
month of June, 1893, in investigating the geology of Essex 
and Willsboro’ Townships, Essex Co, on Lake Champlain. 
The townships lie about half way up the lake from Whitehall. 
For portions of the country so long settled it is surprising that 
so little has been published regarding the local geology, and we 
have found no map giving accurately even the geographic 
features. 
Together the townships embrace about one hundred square 
miles; Essex about forty and Willsboro’ about sixty, including 
the Four Brothers’ Islands, in Lake Champlain, two miles off 
shore. The Boquet river flows nearly due north through the 
entire length of Essex township, divides it almost equally, 
then bends abruptly near the village of Willsboro’ Falls, broad- 
ens and enters the lake. This river forms the boundary between 
two distinct classes of formations and topography : 
1. The level country east of the Boquet, between it and the 
lake shore, consisting of paleozoic formations overlain by forty 
feet or more of drift material, clay, gravel, sand and subsoil. 
2. The region of rounded, rocky hills, rising to the westward 
of the river, and composed almost exclusively of gabbros and 
anorthosites, of varying appearance but essentially of the same 
constituents. 
Prof. F. D. Adams,+ whose classification we adopt, refers 
the latter to the Norian or Upper-Laurentian in Canada, where 
similar rocks occur, These Norian hills up to fifteen hundred 
feet in height, range through the western part of both town- 
ships, accompanied by apparently earlier metamorphic lime- 
stone, schist and granite. They are partially covered by hills 
of stratified sand, which are remains of Quaternary beaches. 
The crystalline rocks reach the shore only along the west side 
of Willsboro’ Bay, and on Split Rock Point. Flanking the 
Norian hills on the east, along the valley of the Boquet, is 
the Potsdam quartzite. This in turn is followed by the Calcif- 
erous sandrock. Both curve to the lakeside in following the 
*The results of these investigations were incorporated by Prof. Kemp in 
making up the geological map of the district, for the forthcoming geoloxical 
map of New York State, and were reported to Prof. James Hall, State Geolo- 
gist. 
+F. D. Apams: Uber das Norian oder Ober-Laurentian von Canada. Neues 
Jahrbuch. Beil. Band, VILL. : 423. 
