GLACIAL ROCK SLIDING 
F. O. JONES 
A geological curiosity in the shape of a displaced mass of rock 
resulting from ice-pressure during the glacial invasion has been 
partially uncovered in the Voight quarry, three miles north of Elmira, 
N. Y., and one-half mile south of Latta Brook ravine. Reference may 
be had to the Elmira sheet of the United States Geological Survey, 
but the contour lines represent the topography only in a general way. 
The quarry is located in the face of a ledge which extends out 
some 300 feet from the main hill. At its southern end the cutting is 
only 37 feet deep, but the linear extent is nearly 4oo feet. The bottom 
is about 35 feet above the valley level, making the present approximate 
height of the point 70 feet. 
Massive sandstones form the bottom of the quarry, but they 
rapidly thin out, and the upper third is very largely composed of 
shale. This formation has received the local name “High Point 
sandstones.” The strata have a northward dip of about 50 feet 
per mile, and their position indicates that the axial inclination of the 
Elmira anticline, to which they belong, is fully as great eastward. 
Their position was, therefore, an important factor in the amount of 
pressure required to move the load. 
The south side of the ledge is in the form of steps or small terraces, 
which remain as they were in preglacial times, and it is down over 
this serrated slope that the rock mass was shoved. Its present form 
is indicated much more clearly by the accompanying sketch than it 
could be by a detailed description. ‘The base or shoe on which the 
slide occurred is a hard, blocky sandstone 12 inches thick, and it 
is chiefly owing to this fact that its character can be recognized. 
Any attempt to delimit the slide must be largely conjectural, 
owing to the till covering. ‘There are 50 feet of the basal sandstone 
in sight, and at one point 7 feet of shale and thin sandstones remain 
t Museum Bulletin No. 81, Watkins and Elmira Quadrangles (Albany, N. Y., 
1905). 
485 
