322 J.D. Dana on American Geological History. 
and twenty miles in the Connecticut valley: and similar strata 
occur in Southeastern New York, in New Jersey, Virginia, North 
Carolina and Nova Scotia. These long valleys are believed to 
ave been estuaries, or else river courses. 
The period of these deposits is regarded as the earlier Juras- 
to a depth equal to this thickness, as the accumulation went on, 
since the layers were formed successively at or near the surface. 
Is it not plain, then, that the oscillations, so active in the Ap- 
b g 
d not the tension below of the bending rocks finally 
cause ruptures? Even so: and the molten rock of the earth's 
neath and the overlying san ° : 
tains, ridges, = thickly studding the Connecticut Valley, 
standing in es along the Hudson, and diversifying the 
* This Red Sandstone, after being known for a while under the name of “ Old Red 
Sandstone,” was long called the “New Red Sandstone,” it being shown to be above 
was made by Mr. J. H. Redfield in 
valley published in 1836, who made it Jur ‘ i 
N. Y,, vol. iv.) Mr. W. 0. Redfield added to the facts bearing on this conclusion 
through discoveries made in New Jersey and Virginia. Prof. W. B 
from. the eoal plants of the Richmond beds, the same age for those beds, while ad- 
. . ds 
; : belts in 
in the belt in Pennsylvania near Phenixville, and one plant (Lycopodites Willi 
nis) common to Virginia and Massachusetts, he suggested that all the beds were 
probably Jurassic Am. J. Sci. [2], xi 3). . E. Hitchcock, Jr. detected re- 
cently a fossil plant (Olathropteris rectiusculus, Am. J. Sci. [2], xx, 92), near the 
. . ch = 4 ; ; 
nm in t 
the existence of the Lower Jurassic at that place, and also renders it probable 
as far as now under 
sandstone, while it may cover part of the Triassic, is mainly Jurassic. 
