312 The American Geologist. ^^^'^ i^*'*- 
point. The section passed down a gulch in which the Hmestone has been 
removed and the relations of the adjacent regions is indicated by- 
dotted lines. The profound faulting is very evident from a distance at 
this point. The red beds are still to the west. The section is abbreviated 
and condensed to the west in order to give room to display the strata 
on the east slope. The elevation is about 9500 at the apex of this sec- 
tion. 
ANCIENT LAKE BEACHES ON THE ISLANDS IN 
GEORGIAN BAY. 
By Fbank M. Comstock, Case School of Applied Science, 
Cleveland, Ohio. 
PLATES XVIII— XIX. 
One day several years ago while following the trail between 
"the chimneys" and the Indian village on Beausoleil island, one 
of the larger islands in the southeastern part of the Georgian 
bay, the traces of several old shore lines were seen so plainly 
recorded in the sandy soil of the island, that it seemed to the 
writer that the locating of some of the more prominent of the 
ancient lake beaches upon the islands of the bay would be an 
interesting problem. In the literature of the subject available 
to the writer no record of these beaches among these islands 
was found, though Taylor*- and Spencerf had both recorded 
beaches at several points on the main land at this end of the 
bay. A few days therefore in the summers of 1900, 1901 and 
1903 were made available for the purpose and three of the isl- 
ands in the southeastern part of the bay were examined rather 
carefully. The results of these examinations are given here- 
with. 
The altitudes in most cases were taken with an aneroid ba- 
rometer, though a hand level was also used as indicated below, 
and the bights reduced to the mean level of the bay (582 feet). 
At the dates when the measurements were made the level of 
lake Huron was about two feet below the normal (580 feet). 
The islands on the "north shore" of the Georgian bay, num- 
bering over thirty thousand, are for the most part rocky and 
sparsely timbered. They vary in size from a small rock to an 
* "The Limit of Post-Glacial Submergence in the Highlands east of Georg- 
ian Ba3-." Amkkican Geologist, vol. xiv, p. 273. 
"The Second Lake Algonquin." Amkkican Geologist, vol. xv, p. 100. 
t "Deformation of the Algonquin Beach and Birth of Lake Huron." Amer- 
ican Journal of Science, 3rd, vol. xli, p. 12. 
