DRIFT DIVISION. 
179 
“ The following are the principal varieties of rock: 
1. Greenstone in all its varieties. 
2. Red and grey sandstone, and their varieties. 
3. Serpentine like that at Hoboken. 
4. White primary limestone, like that at Kingsbridge. 
5. Granite and gneiss, like that found on the island. 
6. Hydrous anthophyllite, like that found in place on the west side of the island. 
7. Greywacke, like that found in the valley of the Hudson above the Highlands. 
8. Limestone like that of Catskill. 
9. Ferruginous sandstone or jasper rock, like the sandstone underlying the Palisades near Fort 
Lee. 
10. Clay stone, supposed to be from the same source as the last. 
11. Actynolite, supposed from the anthophyllite locality. 
12. Kyanite: this has been found in small fragments, but I am not aware that it has been traced to 
its locality. 
“ The abundance of the several varieties of rock above enumerated, is very different in dif¬ 
ferent parts of the island. While some are common to every section, others are confined to a 
particular part; thus, greenstone is found in boulders every where from north to south, and 
from east to west; while serpentine, like that at Hoboken, is confined to the southern limits. 
The details of these facts will be found below : 
1. Greenstone. This in all varieties is perhaps the most abundant rock that is not found in 
place on the island, yet in boulders is common to every part of it. In almost every instance, 
they are worn to a rounded form, though it is one of the hardest and toughest rocks known. 
They are among the largest transported rocks on the island, being from ten to fifteen feet in 
diameter, and often covered with grooves and scratches indicating the mechanical violence to 
which they have been exposed. This rock is not found in place on the east side of the Hud¬ 
son, but is the chief rock on the western shore, from Tappan bay on the north to Bergen hill 
on the south ; and as all the varieties found in place there can be selected amongst the boulders 
here, the necessary inference is, that this locality is also the source of the greenstone. Spe¬ 
cimens are in the State Museum. 
2. Red sandstone, like the greenstone, is common to every part of the island, being found 
from Corlear’s hook to Kingsbridge, but most abundant towards the former place. These 
boulders vary considerably in appearance, as well as in size. Though occasionally consisting 
of coarse pebbles, they are generally fine grained, of a red or greyish red color, and distinctly 
stratified. I have found some that measured nine or ten feet in diameter. This rock, like 
the greenstone which it accompanies along the Jersey shore, is not found on the island, nor 
on the east side of the Hudson nearer than the valley of the Connecticut. There are two 
other varieties which I have referred to the red sandstone formation, but on account of their 
peculiar character as boulders, I will describe them by themselves under the name of ferru¬ 
ginous sandstone and claystone. Specimens are in the State Museum. 
