20 NEW YORK STATE MUSEUM 
of the Adirondacks on the north and the comparatively hard lime- 
stones immediately southward. The work of erosion has made 
rapid progress in this belt of weak rocks, and at two places, Little 
(ons Gh) LE \ 
== 
Fic. 7 Geologic and topographic sketch map and structure sections of the 
vicinity of Little Falls. Crosslined area at bottom of gorge—=  Precambric 
rock (syenite); blank areas—Little Falls (Cambric) dolomite; vertical 
line areas— Trenton (Ordovicic) limestone and shale; horizontal lined 
areas — Utica (Ordovicic) shale; dotted areas Quaternary sand and 
gravel. Heavy black lines are faults. The structure sections show the con- 
dition of things along the lines AB and CD. In the sections the vertical scale 
is four times exaggerated. 
Based upon map by H. P. CusHInG 
