304 
GEOLOGY OF THE FOURTH DISTRICT. 
Fig. 1, is a sketch from the western shore of Seneca lake, near Big-stream point. 
Fig. 2, is a sketch from the bank of the creek above Lodi falls, near VVyckoff’s mill. 
a, a, a, are uniform planes of perfect smoothness. 
b, b, are curved surfaces, having a general vertical direction, and of equal smoothness with the others. 
Sometimes the interstratified impure sandstones interrupt the joint, and the lines above and 
below do not coincide. In the greater number of instances, however, these thin strata offer 
no impediment to the passage of the joint, and the whole mass is divided into huge blocks 
or prisms. This structure, particularly along the lake shores, presents some of the most 
picturesque scenery, resembling the gigantic ruins of Cyclopean architecture, crowned in its 
decay by trees, shrubs and festoons of moss and vines. 
The following sketch is from a beautiful example of this kind, on the shore of Cayuga lake, 
near Ogden’s ferry. 
140 . 
Jointed structure of the cliffs on Cayuga lake. 
