Review of Recent Geological Literature. 339 
glacial currents at Fort Churchill northeastward, in a nearly opposite 
direction to the former course held during the greater part of the Ice 
age. If the total glacial erosion, besides plowing up the preglacial 
stream deposits and general mantle of residuary clay, removed also on 
the average several or many feet from the underlying rock surface, it 
is evident that nearly all the stria? produced during the early and middle 
portions of the Glacial period were erased and their places taken by 
later markings. The ice-currents recorded by Mr. Tyrrell radiating in 
all directions outward from the region west of Hudson bay and east of 
the Telzoa river therefore probably are referable to a late stage of the 
glaciation, when the previously thick part of the ice-sheet covering the 
basin of Hudson bay had been melted, on account of the ingress of the 
sea, more rapidly than its portions at the west and at the east and south- 
east, which consequently for a time flowed into the Hudson bay area, 
engraving the latest and most plentiful courses of striation. 
An opinion here stated by Mr. Tyrrell, that Hudson bay was an inland 
sea during the Ice age, thus appears to be true only for its closing or 
Champlain epoch. The northeastward and eastward glacial stria? re- 
corded by Bell on the northeastern shores of this great bay and along 
Hudson strait, with the extension of the ice-sheet thence eastward be- 
yond the present coast of Labrador, and its extension west and north- 
west, as shown by Russell, Dawson, and McConnell, to the upper part of 
the Yukon basin and beyond the lower course of the Mackenzie river, 
indicate that the area of Hudson bay during the greater part of the 
Glacial period was enveloped by a deep ice-sheet, which, because of its 
thickness and the hight of its surface in that central portion, outflowed 
east into Davis strait and the North Atlantic ocean, south and south- 
west to the Ohio and Missouri rivers, and northwest to the Arctic 
ocean north of the mouth of the Mackenzie. Due south of Hudson bay 
the ice-sheet had its greatest extent in the United Slates, reaching in 
southern Illinois 200 miles farther south than in New York and New- 
England. Drift from east of Hudson bay also was carried far south- 
westward. Boulders of a peculiar rock formation which occurs in place, 
so far as known, only on the east coast of this bay where it narrows into 
James bay, are plentiful in the drift southwest of James bay and con- 
tinue to North Dakota and southern Minnesota, 1,000 miles from their 
outcrops. 
Drumlins or ridges of t ill, and eskers or ridges of sand and gravel, 
were commonly found, throughout the region traversed by Mi'. Tyrrell, 
on the areas having a considerable average thickness of drift deposits: 
but some tracts, as the shores of ( Jhesterfield inlet and part of the north- 
west coast of Hudson bay, are largely bare rock. Theeskers often were 
observed to extend long distances, "parallel to the glacial Striae, over 
hills and through valleys and lakes, quite regardless of the surface con- 
tour of the country." 
Strand lines of the Late Glacial or Champlain marine submergence 
wen- seen along all tin- lower part of the Telzoa river, the first and high- 
est being about 400 feet above the present sea level. Near Fori Churchill, 
