ONTARIO DIVISION. 
357 
northeast, from where the main fractures cross each other, and the rocks disappear below the 
more recent formations, while their southwardly extremities almost always present high pre¬ 
cipitous, and often vertical cliffs. 
The continuation of the axis with which the wrinkles were connected, may be traced farther 
to the south in the Comfort hills of Orange county, between the Walkill and the Shawan- 
gunk rivers, and is probably an extension of that of Pochunk mountain on the New-Jersey 
line. The transverse fractures, and upheaves connected with them, and crossing the axis 
above mentioned, have given a great bend to the Mamakating valley to the eastward. This 
axis extends to the north by Catskill, Glen’s falls, Saratoga lake, Baker’s falls, and may 
with propriety be called the Hudson axis. It skirts the river more than one hundred miles. 
The Shawangunk anticlinal axis forms the Shawangunk mountains, from the New-Jersey 
line to near Wawarsing, where it disappears, or is traced with difficulty. This is a continua¬ 
tion of that of the Kittatinny or Blue mountain of New-Jersey and Pennsylvania. 
Diagrams and sections illustrating the superposition, derangements, etc. of the Shawangunk 
grit and the associated rocks, may be seen on PI. 5, fig. 13 ; PI. 6, fig. 7 ; PI. 7, figs. 2, 3, 4 ; 
PL 8, fig. 4 ; PI. 15, fig. 3; PI. 26, figs. 4, 5, 6, 7, letter (a) grit, (6) water limestone ; and 
PI. 39, figs. 1, 2, 3. 
Economical applications, and Mines. 
The useful applications of the Shawangunk grits are not numerous ; they are for mill-stones, 
building stones, and glass. 
The firm coarse grits have been long quarried for mill-stones, and have been extensively 
used. They are known in market by the name of Esopus millstones.* They are still quar¬ 
ried to a small extent; but since the French buhr stone has been brought into common use 
for millstones, the Esopus stones are in less demand. Many small millstones, for family use, 
in grinding corn among the planters of the southern States, are still manufactured and sent 
to market. 
The finer white and grey grits, which frequently resemble granular quartz, are well adapted 
for the manufacture of glass ; and it is believed that the glass factory at Ellenville, Ulster 
county, makes use of this material. I know it was iii contemplation to do so at the time of 
its erection. 
These fine grits would make a beautiful and durable building material, which is as easily 
dressed as the common granites. Localities were seen, within less than two miles of the 
canal, where blocks could be procured three to five feet thick, and five to twenty feet in their 
other dimensions, without a seam, and on which the weather has produced no perceptible 
effect during the ages through which they have been exposed. Such rock as this the engi- 
* Esopus was the name of the township and village of Kingston, during the war of the revolution; and as these stones were 
quarried at no great distance, and were shipped from that vicinity, they have acquired the name of Esopus millstones. Esopus is 
now the name of a township and village a few miles south of Kingston. 
