Geology. 273 
is Pe gay Ns | Old Rel S 3.2 \ 7 h ae | 1 
9. 1. 
the whole series, to the Potsdam San dstone, there. is perfect. and close 
somormsbillty and no such unwonted change in fossil life as to constitute 
systematic except at one place—the Oriskany Sandstone, the 
an of the Devonian in New York,—there sii - sg of like im- 
portance at the Oneida conglomerate period, © to. an opinion 
towards. which able. geogists are now inclin mites iy which leads 
Pen to consider the break at the Oneida conglomerate as systematic. 
All the palzozoic groups of New York slowly pass one into the 
er yy gradation of mineral and organic characters, with easily ex- 
Hine peeeptians, 
4. The palzeozoic strata of New York are comparatively thin. They 
ion. 
5. De Verneuil rightly divi des the New York groups. into two great 
classes,—the “ constant fee the. “local.” oe pee former are Pots- 
dam Sandstone, enton Limestone, and Niagara, Among the latter are 
the pein ons Necest ans and perhaps Oneida conglomerate, éce. This 
a use 
x That it Shots convenient. and mata hes divide. the Silurian ane 
Devonian srstems of this State. each into three stages,—the divisi 
bei change of sediment and thei fossil contents. 
1. The Middle ey stage is, a period of especial transition—from 
al from their innumerable and 
minute ternatio: at from the organic povert, 
8, That the ons esence of Oneida a glo; Pes 2 aes does not 
Pipa a change of name for all the strata below it (of “ Cambrian” 
thange,—not, even if there be volcanic. intercalation, ion, provided there is 
conformableness, and some community of fossi 
Oneida conglomerate seems to be local, is supernumerary, and 
only found at present on the east of Middle North America. 
in the eariening 9 ct of metamorphism is seen only 
neighbor of h 
10, The New. York hynogene rocks, few uplifts, and those. of limited 
magnitude ; no o uplifts ardng it into a series of deep basins contained 
in hypogene beds, as in Bohemia, Wales, &c. * Neither has it sheets of 
teat vl Vole ois (conformable,) save in the Potsdam rock om 
Uperio 
This basin = “lay” ‘tion of its own, as a number of undulating 
sheets of sediment, dipping. slighty to the southwest, here and there 
be tty 8 Peak of crystalline se and in certain regions raised into 
Fa The sedime od wig age of thes basin have submitted to two kinds 
Fblutonte disturbance, independen nt of each other, and acting at distant 
i Ist, that of secular. or slow oscillation during de sg Na 2nd, 
nes ~ disturbance arising from paroxysmal uplifts long 
12. The whole — ie peer" series of strata having, 9 
ition, s 
whether it does” n ot wd 
