MeetiiKj of the Amerhutit Assoriaflo)). — Upham. 231 
27. Posf-Ci-etaceons Grade -plains in southern Netv England. F. P. 
Gulliver. The Jura-Cretaceous peneplain of the eastern United States 
has been elevated and dissected. The elevation of southern New Eng 
land was from 150 to 250 feet, causing grade-plains to be developed for 
one or two hundred miles inland. Afterward the land was again op- 
lifted 100 to 200 feet, and grade-plains were again developed at a greater 
depth. The land still continued to rise, and trenches were cut below 
the level of the second lowland grade-plains. Lastly, a slight depression 
now allows the sea to enter some of the valleys. 
28. The Algonquin River. G. K. Gilbert. The channel of this 
Pleistocene river was first observed and named by Spencer in 1888, be- 
ing then described as the outlet of lake Algonquin. It flowed from the 
old lake at the site of Kirkfield, Ont., down the Trent valley to Jake 
Ontario. In 1891 Spencer hesitated between this opinion and the view^ 
that the Algonquin water was a gulf of the ocean, the relation of its 
highest plane to the Kirkfield pass being a coincidence. In papers 
published this year he has adopted the latter theory without reserve. 
Last autumn Mr. Gilbert examined the upper course of the Algonqwin 
river from Kirkfield to Fenelon Falls, and traced considerable parts of 
its lower course, finding everywhere unmistakable channel characterK. 
The Trent drainage valley includes many lakes. In the shorter stream 
ways between lakes the drift, originally from 20 to 70 feet deep, has 
been removed for a width of one mile, e.xposing bare sills of Trenton 
limestone. In longer stretches of constricted passage the width of the 
old channel ranges from 1,500 to 3,000 feet, and the bottom is often 
paved with great boulders. Above Rice lake the channel is divided, one 
part following the Otonabee, the other Indian river. There is a delta at 
the estimated position of the Iroquois plane : but, as that is also the 
plane of Rice lake, the correlation with lake Iroquois is questionable. 
The old Pleistocene channel does not stop at Rice lake, but continues 
with undiminished strength to lake Ontario at Trenton. 
It follows, (1) that the Algonquin water was a lake, and not a gulf : 
(2) that during the epoch of the Algonquin river the Niagara drained 
only the Erie basin ; and, (3) that the waning of the ice-sheet opened 
the upper St. Lawrence valley before it opened the Mattawa vallpv. 
(The last inference has been reached also by Taylor from independent 
data.) 
Spencer has traced the Algonquin shore line as it descends froMi 
Kirkfield and from the vicinity of lake Simcoe, westward along the 
south side of Georgian bay and in the Huron basin ; and Tayk)r has 
recently observed it at Sarnia and Port Huron, where it is not far above 
the water of lake Huron. I infer (thus agreeing with Taylor's latest 
and Spencer's earliest opinion) that the outlet of lake Algonquin was 
diverted by terrestrial deformation from Kirkfield to Port Huron ; and 
it follows that the opening of the St. Lawrence passage and the resuU 
ing disappearance of lake Iroquois preceded that diversion. These re 
suits have a bearing, not only on the use of tht^ Niagara gorge as a 
chronometer, but on the comparative geography of the iCe-front. 
