MICHIGAN ACADEMY OF SCIENCE. 
1 1 9 
(A) GEOLOGICAL EVIDENCE OF FORMER ELEVATION. 
We will take first the geological (and bathymetrical) division, listing 
the lines of evidence of former elevation of lands relative to sea level 
as follows: 
1. Glaciation. 
2. In addition to the above, Fjords excavated by ice far below the 
present sea level. 
3. The presence of submerged valleys of river erosion upon the con- 
tinental borders. 
4. Other geological evidence, the nature of particular formations, etc. 
GLACIATION. 
To whatever degree the epeirogenic theory of glaciation is accepted, 
glaciation itself becomes admissible as evidence of former greater alti- 
tude above the sea. To that extent it is offered as bearing upon the 
present discussion. Figure 1, in addition to the conventional areas of 
North America and Europe includes also certain others, of small extent, 
for instance the Alps, where there are signs of a former greater extent 
of glaciers which are now comparatively small; similarly the Lebanon, 
Himalaya, Atlas and Andes mountains,* New Zealand and southeastern 
Australia. 
In the highlands of Nicaragua, Beltf found transported boulders and 
other signs of glaciation (with the exception of grooved rocks) as 
characteristic, as he remarked, as any in Scotland. 
Whatever one may think of Professor Agassiz’i opinion that South 
America was formerly glaciated right up to the equator, he did find large 
transported blocks in the mountains not very far from the Amazon and 
he seems safe in the inference that these mountains at least were 
formerly considerably glaciated. Etis observations were substantiated by 
his fellow-traveler Hartt§ who also found morainic deposits in the south- 
eastern part of Brazil near the coast. 
These small scattered occurrences of glaciation where there is now 
none or where the glaciers if present are much smaller than they were 
once, are offered in evidence conditional upon the acceptance not only 
of their verity but, together with the larger areas, upon the acceptance 
of the theory that glaciation was brought about principally by the dif- 
ferential elevation of the land to the local line of perpetual snow. Dif- 
ferent estimates of the amount of elevation which would be required 
to reglaciate North America to the former extent vary from 3,000 to 
8,000 and even 10,000 feet. 
FJORDS. 
Figure 2 illustrates the principal regions where fjords have been 
excavated by glacial ice to considerable depths below the present level 
of the adjacent seas. All the arctic lands of America, the coast from 
Puget Sound to the Alaskan Peninsula, Greenland, Scandinavia and 
doubtless Spitzbergen also, are included in this category. Also, possibly 
*See Darwin, Charles, “Origin of Species,” 1859, Levant Ed. pp. 366-371. 
fBelt, Thomas, “The Naturalist in Nicaragua,” London, 1874. 
JAgassiz, Louis, and Mrs., “A Journey in Brazil,” (Thayer Expedition 1865) 1886. 
§Hartt, Ch. Fred, “Geology and Physical Geography of Brazil,” 8 1870. 
