Pleistocene Changes of Lerd. — iJedcer. 43 
vations, has not ([uite lillcd it up, yet there appears to l)e no con- 
tinuation of it on the otlu'v side of Long Tshind, even beyond the 
glacial deltas. 
This curious fjord-like shoaling of the submarine channel, be- 
fore it reaches the edge of the continental plateau, is repeated by 
the submerged river channels described liy A. Lindcnkohl from 
the J^elaware and Chesapeake bays. 
This phenomenon might perhaps be explained according to T. 
F. Jamieson's suggestion for certain fjords, as a consequence of 
the unequal and intense subsidence of an ice-loaded continent. 
But concerning these channels, as well as the one described by 
Chalmers in the St. John river estuary and the large channels 
reported l)y Spencer from the gulf of St. Lawrence and several 
other places, we must allow that at present we know very little 
indeed of their history and i)recise age, with perhaps the general 
exception that they may. "point to a high elevation in early glacial 
time. 
In this connection it is of interest that in America as well as 
in Europe the interglacial marine deposits at present accessible 
above the sea level are found only near the margin and at the 
outside of the region, which, during the last glaciation, has been 
exposed to subsidenci'. I refer here to the interesting fossilifer- 
ous deposits described by Shaler, Lpham and others, from Nan- 
tucket, Marthas Vineyard, I.,ong Island and Boston. The (pies- 
tion whether the Columbia formation belongs to tiie same sub- 
sidence cannot safely l)e discussed, before its marine origin is 
conclusively shown Ity fossils, lioundary shoie-lincs. oi' othei' in- 
disputable evidenee. The same is true of tlu' lowei- licds of sand 
and clay al)ont .")(» feet thick which Lyell in tlu> ve|)oi-t of his first 
voyage to North Anici-ica describes from Beaupoi-t near Quebec. 
The clay with honlders, which he observed resting upon these 
beds and concicmI hy fossiliferous, late glacial de|)()sits, is, as I 
could myself ascci'taiii. a true till, pi'ohalily belonging to the last 
glaciation. 
Though the situation of these possibly interglacial deposits is 
open to the St. iiawi'cnce estuary, their marine oiigiii is vei'y 
(inestionable. since no fossils have been found. 
ibit if it is dillicult to get any idea of tiie interglacial gcoid 
deformations from the mai-ine deposits, it is still moi-e so with 
respect to the scanty i-eninants ctf l.-ike sediments. As compared 
