Sandstone of the United States. 211 
The working of the quarry beiow this is interrupted by 
water. i 
The following are some of the varieties which occur at 
these mines: 
1. Grayish white fine grained Sandstone. 
2. Brown red do. do. 
3. Vermillion red do. do. 
4. Sandstone containing nodules of indurated marl, some- 
times called clay galls. 
5. Conglomerate with pebbles. 
6. Sandstone with greenish specks, and containing decom- 
posing feldspar. 
7. Sandstone divided into thin plates by shining lamin of 
marl. 
§. Sandstone, grayish white with red spots. 
9. Sandstone, dark gray, brownish yellow, and various 
shades of red. 
In some parts of the quarry are found grayish white mica- 
ceous sandstones, containing vegetable impressions, with the 
bark converted into coal. 
Some of the Sandstones contain small crystals and plates 
of green carbonate of copper, others have on their surface 
illinitions of manganese. 
Copper mines are now opened in this formation, at Belle- 
ville, Somerset, and Bridgewater, New-Jersey. The lead 
mine at Perkiomen, Pennsylvania, belonging to Samuel We- 
therill, Esq. is situated in a Sandstone of the same age. 
In the vicinity of Princeton the rocks possess a similar 
character, and are composed of parallel strata of compact 
and slaty Sandstone, and indurated marl. 
Atthe rocks, near the Delaware, ten miles South of Easton, 
Pa., the second Sandstone forms abrupt precipices, in many 
places, much decomposed, and presenting the appearance of 
massy columns. 
The formation upon which the trap rocks (the newest fletz 
trap of European geologists) repose at Patterson, is second 
or variegated Sandstone. 
Taccompanied Professor Renwick, on a visit to Passaic 
Falls, and that gentleman coincided in this opinion. Pro- 
fessor Akerly, of New-York, has, I believe, expressed a 
similar idea in one of his publications. 3 
Beneath the Palisadoes, or trap rocks, on the shores of the 
river Hudson, is a sandstone which belongs to this class. 
n) 
