122 
FOURTEENTH REPORT. 
except for a bar which ha.s formed across the month of it. and the ob- 
served depth is 2.844 feet. 
Passing south along the coast the month of the Susquehanna river 
is a similar instance and Spencer* lias shown the details of numerous 
cases of the same sort, so that from the Susquehanna southward, 
around the shores of the Gulf of Mexico and on to the Orinoco there 
are as many as 25 or 30 all having the same general characteristics and 
all being apparently favorable to a reference to pleistocene time. 
Spencer's results in this region have quite generally been regarded 
as excessive. From a faunistic standpoint it is hard to credit the very 
great extent of land which the deeper drownings would perhaps indi- 
cate. running as they do down to depths of 12,000, 14,000, and 17.000 
feet, in the Bartlett Peep south of Cuba a channel coming in from the 
east goes down even to 18,000 feet. It would seem reasonable to sup- 
pose that more than one cause may have operated to give these depths. 
Bartlett Deep stands in the relation of a foredeep for the Cuban moun- 
tains and throughout the Antillean region crustal conditions seem to 
have been anything but stable. The fact of the numerous drowned 
channels seems well enough established but we may hesitate to use 
the larger values in making up any average with similar instances else- 
where. 
On the west coast of the British Isles Hullf found a similar channel 
which is now submerged 7,800 feet and in the Bay of Biscay one of no 
less than 0,000 feet, which is getting well up toward two miles. 
On the west coast of Africa, just north of the equator and near the 
meridian of Greenwich, Buchanan found one which he called the “Bot- 
tomless Pitt" which sounded 2,700 feet; but the greatest of them all in 
clearness, length and general conformation is the one which he figures 
for the mouth of the Congo. It is 6,000 feet deep. It extends out to 
the edge of the continental shelf, a distance of about 80 miles, it is cut 
in that shelf, and its drowning, like that of all the others of its class, 
is inseparable from the drowning of the continental border in which 
it is situated. Further on, when we see how the submerged border is 
fairly a unit feature all over the world, we shall see how these drowned 
rivers and with them the lands themselves even though scattered, are 
susceptible of correlation in their drowning, making their elevation 
high above sea level during the Glacial Epoch (possibly before) termin- 
ate with the Champlain depression in eastern North America. 
Since all of the information relative to these submerged river valleys 
and the mouths of fjords is derived from soundings in the ocean near 
the land it is obvious that most of the observed depths must be minima. 
How much deeper they would be in the absence of sedimentation which 
must have occurred we can only guess, but we find some hint in the fact 
that western Britian gives an instance of 7,800 feet, the Bay of Biscay 
9,000 and the mouth of the Congo 6,000. 
♦Spencer, J. W., ‘ The Reconstruction of the Antillean Continent,” Bull. Geol. Soc. Am., Vol. 6, 1895, 
pp. 103-140. With plate. 
This author speaks of these river channels as “fjords” but it seems best to include them here with 
the other instances of river-as distinguished from ice-erosion. 
tHull, Edward, “The Submerged Itiver-valleys and Escarpments off the British Coast.” “Nature,” 
vol. Ivii, 1898, p. 184. 
Hull, “Sub-Oceanic Terraces and River Valleys of the Bay of Biscay.” “Nature,” vol. Ivii, 1898, 
Hull. “Sub-Oceanic Terraces and River Channels off the coast of Spain and Portugal,” “Nature,” 
vol. lviii, 1898, p. 51. 
