Plate 15 
A ledge of Precambric rock near Loon lake in the northern Adirondacks, 
showing the very ancient Grenville gneiss in sharp contact with syenite. 
The light and dark banded rock on the right is Grenville and the hammer 
is on the contact. # 
From N. Y. State Mus. Bul. 5, pl. 3 
