PRIMAKY ROCKS, 
535 
stratification and dip along the banks of the Hudson, and at their western margin, than in 
their centre. Among the varieties of gneiss in the county, may be mentioned that in which 
the mica predominates, and that in which the felspar predominates, as being most abundant; 
these occur every where. Next in abundance is that which is called hornblendic gneiss and 
gneissoid hornblende, the hornblende and mica forming the larger proportion of the rock. It 
is very abundant at Long and Sterling mines, and in all the short ridges and elevations form¬ 
ing the western border of the Highlands. Granite is abundant in the primitive region of the 
county, constituting beds and veins. It is coarse and crystalline, on the road from Buttermilk 
falls to Fort Montgomery, and on the turnpike from Monroe works to Haverstraw. It is 
graphic on Rocky hill in Warwick, and other places. It is sienitic in Mount Eve, at Sterling 
iron mine, and many other places. It is compact in Butter hill, fine-grained and compact 
in many places on the road from Warwick to the Ramapo river. All the varieties of color 
are abundant. The red is particularly so in several of the ridges east of Long pond. While 
it is not positively asserted that granite, in this county, is a rock regularly stratified like the 
gneiss, the careful attention of geologists is invited to a locality on the^ northeast side of the 
turnpike from Haverstraw to Monroe works, about three miles from the latter place; also to 
many places on the turnpike from the saw-works to Bellvale, in Warwick. 
“ Immense quantities of rock are found every where in the Highlands of Orange, which 
are neither perfect granite or gneiss, but partake of the characters of both, or is intermediate 
between the two ; and it is this granitic gneiss or gneissoid granite, which embraces a large 
number of the metalliferous deposits found in the county.”* 
The Primary region of Rockland county extends from the northeast corner near Fort 
Montgomery, along the Hudson to below Caldwell’s landing; thence south-southwest along 
the base of the Highlands to the New-Jersey line, embracing all the county west and south 
of the line thus drawn, to Orange county on the west, and New-Jersey on the south. The 
islands called Wagon’s islands, in the Horserace, between Fort Montgomery and Caldwell’s 
landing, are also of the Primary rocks. Stony point, which lies east of the Taconic slate 
and limestone, belongs to this class of rocks. 
1. Granite. 
This rock abounds in Rockland and Orange counties. It occurs in beds, in thick inter- 
truded masses, veins, and irregular masses, forming hills, and often the tops of the mountains. 
The beds and interlaminated masses often present the general aspect of gneiss, and it has 
sometimes been called stratified granite. 
Locations suitable for quarries. 
Granite and granitic gneiss, suitable for quarrying, occur at the foot of Butter hill and of 
the Crow’s Nest. 
Dr. W. Horton, Third Americaa Geological Report of New-York, 1839, pp. 136, 137. 
