U. S. GEOLOGICAL SURVEY 
BULLETIN NO. 313 PL. VI 
A. SANDS QUARRY IN VINALHAVEN. LOOKING S. 80° E. 
Showing the curvature of the sheets, the intersecting joint face, and the N. 10° E. channeling along 
the " cut-off. :: 
B. WHITE QUARRY IN BLUEHILL. LOOKING N. 10° W. 
Showing the lenticular sheets crossed by a vertical joint curving from a N. 50° W. to N. 50° E. course. 
The black vertical streaks are " underground water" issuing from between the sneets. 
