260 
The American Geologist. 
April, 1896 
railway, about 300 miles long, crossing the island from east 
to west. Ten coal seams are found in the area around the 
northern end of Grand lake, and one of these, 3^ feet thick, 
yields coal which, on being tested at St. John’s, proves to be 
of superior quality. Near the west end of the railway, in the 
vicinity of St. George’s bay, three coal seams, respectively 4 
feet, 4-J feet, and 5-J feet thick, are exposed by excavations; 
and it is stated that, with accompanying thinner layers, an 
aggregate thickness of 27 feet of coal is determined in that 
field, which has an extent, so far as yet ascertained, of five 
miles or more, with a width of at least two miles. 
Erosion of the St. Croix Dalles. 
Mr. Warren Upham, in a lecture March 18th, at Taylor’s 
Falls, Minn., on “ The St. Croix River before, during and 
after the Ice Age,” attributed the erosion of the narrow but 
short gorges or canons called the Upper and Lower Dalles, 
close below the villages of Taylor’s Falls and St. Croix Falls 
on the opposite Minnesota and Wisconsin sides of the river, 
to the Aftonian and Wisconsin stages of the Glacial period. 
Previous to the Ice age it appears that a watershed of trap- 
pean and Upper Cambrian rocks there extended across the 
present valley. Five-sixths of the basin, lying above the 
Dalles, was probably drained during the Tertiary era by a 
watercourse leaving the present St. Croix valley near the 
mouth of the Sunrise river and running south and southwest 
to the Mississippi somewhere between Anoka and Minneapolis. 
This was the preglacial St. Croix. Below the Dalles was the 
preglacial Apple river, flowing to the Mississippi along the 
present lower course of the St. Croix river, where it is now ex¬ 
panded in the lake St. Croix. The channeling of the pic¬ 
turesque Dalles, which are the central attraction of the pro¬ 
posed Inter-State Park, seems chiefly attributable to an 
interglacial river of the Aftonian time of extensive retreat of 
the ice border in the upper Mississippi region: but these 
gorges have undergone further changes by Late Glacial and 
Postglacial stream erosion, and their walls of trap rock have 
been much riven by frost along vertical joint planes. 
Glacial Drift Island in Barents Sea. 
Kolguev island, having an area of about 2,000 square miles, 
and a maximum altitude of 250 feet, situated in Barents sea 
130 miles southwest of Novaya Zemlya and about 50 miles 
distant from the nearest mainland of arctic Russia, is found 
by Mr. Trevor-Battye and Col. H. W. Feilden to consist 
wholly, so far as observable on the surface and in sections, of 
glacial and modified drift. Deposits of sand and gravel, with 
frequent boulders, extend in some places, notably on the 
highest plateau and in outlying hills, to maximum depths of 
