1883. 25 Trans. N. Y. Ac. Sct. 
boulders occur, perched often on narrow ridges which run to the river, 
and forming a marked feature in the scenery. 
In regard to the material of the transported boulders and pebbles, 
a less variety occurs here than on the southeast of the Shawangunk. 
A locality of great interest, which I have studied with some care, 
is at Mountaindale in Sullivan County, at a railroad cut one-half mile 
west of the station. This is situated in a little cross valley standing 
about W. N. W. and E. S. E., through which a small stream, the 
Sandburg, has cut its way into the Champlain deposits, leaving a series 
of well-marked terraces, sometimes six or eight, on either bank, and 
empties into the Mamakating valley. Across this little valley, at right 
angles to the course of the stream—so that it diverges northeastward, 
and so runs around close to the rocky bluff on its left bank—is thrown 
a huge natural embankment, like adam, with a steep face on its N. 
W. side, and a long slope to the southeast ; its height may be a hun- 
dred and fifty feet. The railroad cutting passes through the upper 
portion of this embankment, and the section gives a good view of its 
constitution, at least in its upper part, for a thickness of from 25 to 35 
feet. The materials are varied in kind and size, and much mixed, 
although a rude sorting is shown by lines at intervals of six or eight feet 
in depth. The pebbles are mostly small, less than six inches in dia- 
meter. Many boulders of subangular form also occur, of one to two 
feet in diameter, and also a number of angular blocks, from three to six 
feet in diameter. 
The material of the smaller pebbles, up to eight inches in diameter, 
largely consists of red shale, mostly in subangular tabular fragments, 
often containing fucoids. Also sandstone is abundant, fine to coarse 
grained, in pebbles of all shapes and sizes. White vein-quartz occurs, 
rarely in fragments exceeding half an inch in diameter, as well as 
several other varieties of shale, a reddish white quartz sand and a very 
little clay. All these materials are evidently of local origin, derived 
from the adjacent beds of sandstone and shale, with their occasional 
thin veins of quartz. 
The larger blocks consist of graywacke, mostly of the vicinity, but, 
in a few much rounded boulders, apparently from the Catskill region, 
and all show an arrangement with the longer diameter in the plane of 
stratification. The number of large boulders, two feet in diameter or 
over, seems to be very small in proportion to the whole material. 
That taken out of the cutting has been used in the construction of a 
neighboring railway embankment, and the laborers have left along 
the sides of the track the boulders of a weight too great to be easily 
moved. Less than a hundred boulders thus remain, of three feet or 
more in diameter, and this would indicate a proportion of but a small 
