40 The American Geologist. 
Julv. 1903. 
remain in New Brunswick to prove the former existence in the 
region of strata belonging to the lower portion of the Devonian. 
These however by their nature plainly indicate that they are 
shore-formations and not the product of the open sea. 
In its southeastern portion the deep gulf is now but faintly 
indicated on geological maps by the embayment of the strata 
south of the Adirondack^ towards the Hudson river, and even 
this has been much obscured by subsequent compression and 
erosion. But the Marcellus shale of New York and Pennsyl- 
vania is a memorial of the enormous wash that was brought 
down by streams that flowed off the newly raised land in the 
northeast. There the ancient Archaean and the more recent 
Cambrian and Ordovician strata were in process of destruction 
and the weather-beaten, scarred synclinal mountains of New 
England are standing monuments of the extreme severity of 
the erosion and the length of time through which the agents 
of degradation have been at work. 
In determining what has become of all the coarser material 
that must have been produced by denundation of so extensive 
an area of land containing so much sand-yielding rock, the 
continued elevation that went on in the region must be consid- 
ered, whereby the upper reaches of the estuary of New York 
were brought above water-level as fast as they were filled with 
sediment. In these the coarser part of the river wash was laid 
down. Consequently these upper beds of sand were soon again 
exposed to erosion, were cut down and carried away to form 
newer strata farther out to sea and their material is met on 
higher horizons after it has undergone a double degradation 
with an intervening uplift. Moreover, on its first elevation, the 
.New England area involved was probably covered with Ordo- 
vician and Silurian strata to a greater or less but unknown de- 
gree, all of which must have been swept away before the eros- 
ive force could begin to attack the older, harder and sand- pro- 
ducing rocks beneath them. The earlier portions of the mater- 
ial swept off such an area would contain less arenaceous sub- 
stance than the later ones and this, combined with the cause 
previously assigned, probably contributed to the scarcity of 
sand in the lower deposits of the middle Devonian of New 
York, such as the Marcellus black shales. 
