42 Ihii AllKfl'lCUn, (Jtolo(Jli<t. .iHTiiiary, 18!>»' 
jservod long since wliieh sliow that these tracts in very modern 
times liave been and perhaps still are sinkinii;. and it is of interest 
thai tlii'se signs of snlisidcnce are fonnd along the Atlantic coast 
))lain ontsith' of the glacial region of ui»lit'tiiig as well as some- 
what within its lionndarv. just ns has been the case in Scandi- 
navia. Thus >ul)niarine peat-liogs are known in New Jersey and 
Nantucket island as well as at the noitheastern end of the bay of 
Fiindy and at the month of bay Chaleur. These last localities 
show that if the rising of land is still going on in the interior, 
the is<il)ase for zero. or. to use Shalers expression, the pivot 
point between the continental upheaval and the oceanic subsid- 
ence, lias moved at least more than fifty miles toward the land 
side. Tht' amount of this subsidence is not yet known, l)Ut at 
the bay of Fnndy it must have lieen at least 40 feet, and at Nan- 
tucket probably 1() feet. Even the numerous small partly sub- 
merged glacial river valleys at the southern shores of Cape Cod. 
Nantucket. Martha's A'ineyard and hong Island, afford evidence 
of a slight sulimergence. The same is the case, as .Merrill has 
pointed out. with the Hudson river estuary, which must have 
subsided somewhat since the channel was cut out of the glacial 
clays in the valley. 
Another (|uestion is whether the deep submarine river valley 
soutlu'ast of New York harbor, so well descril)ed \^\ professor 
Dana, belongs to so late a i)eriod. The fact that its upper end 
d(^wn to a depth of al)out Idd feet has l)een entirely filled up at 
the outside of Sandy Hook seems to indicate that the Hudson 
river leveled the adjacent part of the i)re-existing channel during 
the maximum of the postglacial elevation, having its mouth here 
and not farther out to the sea for a cousidei'able time. The other 
analogons submarine channel descrilied l)y Dana from the north 
side of Long Island may perhaps afford a possibility of deter- 
mining their age. Having crossed Long Island sound in an 
obli(|ue diri'ction. it Ik'couh'S during the last 10 miles more and 
more shallow, ending abruptly at Long Island against thi' 
terminal moraine. Ilei'e it may be possilde to ascertain with a 
few borings, whether the channel, as it api)ears, has been over- 
ridden \\\ the moraines of the last glaciation. and perhaps also 
whether it is younger than those of the first glaciation. 
Though the abi'upt ending of this last channel is very likely 
i\\w to the terminal moraine, which, to iudiic from Hana's obser- 
