288 ROCKS AND MINERALS OF UKITED STATES. 
^* C ( Crystal, quartz, amethyst, chalcedony, car- 
g I j nelion, cacholong, epidote, asbestos, chaba- 
j Greenstone. \ sie, chlorite, hornstone, calc spar, ores of 
! I iron and copper, zeolite, prehnite, selenite, 
•S J VLincolnite, &c. 
P-» Porphyry, Gold, specular oxide of iron, 
g i Epidote, feldspar, amethyst, zircon, fluate of 
w Syenite. < lime, quartz, lead, zinc, copper, titanium, ba- 
^ L i rytes, hypersthene, arragonite, chabasie, &c. 
( Fluate of lime, phosphate of lime, calcareous- 
I spar, argentine, ores of copper, iron, lead, zinc, tin^ 
Granite. ^ manganese, molybdena, titanium, barytes, sulphur, 
I quartz, amethyst, pinite, topaz, chrysoberyl, mica,' 
V feldspar, schorl, beryl, garnet, staurotide, tale, &c. 
Note. — In forming the following table we have consulted all the 
authorities within our reach. But we acknowledge our particu- 
lar obligations to the masterly reports of Prof H. D. Rogers, of 
Pennsylvania, and of Messrs. Conrad, Vanuxem, and the other 
geologists of this state, who are in a fairway to reduce to some-' 
thing like order the hitherto chaotic formations of this country. 
It will be seen from the opposite table that the highest strats 
in the State of New- York are the conglomerates which fornf 
the highest portion of the Catskill Mountains, which, according 
to Professor Rogers, is more than 3000 feet helow the coal meas- 
ures of Pennsylvania. 
For the thickness of the rock formations of Pennsylvania, the 
reader can consult the table on page 242, where the numbers cor* 
respond to those in the present table. 
* The sandstones and conglomerates of Catskill Mountains 
probably belong to the old red sandstone group of Murchison. 
t Professor Conrad, in his "Report," &c., states that this 
group, consisting of olive sandstone and slate, cut through by Sal- 
mon River, together with the preceding red sandstone group, corre- 
sponds in geological position with the fourth group in the slate 
system of Wales, described by Prof Philips. But this appears 
to us a mistake, as the whole of the four groups described by 
Philips belong to the clay slate system, and lie below the lower 
Silurian system^ which consists of the Llandeilo flags and lime- 
stone. This will appear from Mr. Conrad's own statement, that 
the black limestone and shale of Trenton Falls (lying below) cor- 
respond in position to the black shale enclosing beds of gray 
wacke, flagstone, &c., which are joined to the Llandeilo flags. 
We have made this formation correspond with the Wenlocfe 
limestone and slate above the Llandeilo flags. 
