428 PLEISTOCENE OF INDIANA AND MICHIGAN. 



precludes the supposition that the headlands were so long as those farther north. The freshly 

 undercut bluffs are longer and the embayments between them are relatively small and shallow, 

 apparently only the heads of somewhat longer forms. 



Nevertheless, the wave erosion on this shore has been more effective in straightening the 

 shore than it has been farther north, for the Algonquin, Nipissing, and present lakes have all 

 worked more nearly at the same level, or within a vertical interval of 25 feet. Besides, during 

 at least two low stages shore erosion was carried on at a lower level than now, and unless those 

 stages were very, much lower they must have contributed to the same result. 



South of Frankfort in the small embayments at Herring Lake and Arcadia, the Algonquin 

 beach is moderately strong. High bluffs of freshly eroded clay fill the shore intervals between 

 these embayments, one south of Arcadia being over 6 miles long. But the embayments of 

 Portage Lake at Onekama and of Bar Lake 4 miles north of Manistee show nothing above the 

 Nipissing level. (See p. 456.) At Manistee the embayment seems to have been somewhat 

 protected and the beach is weak. 



The Glenwoocl and Calumet beaches of Lake Chicago seem to rise northward north of Grand 

 River and terminate in the great sandy plain 8 or 10 miles south of Ludington, but the Toleston 

 beach remains horizontal. It seems to have the same altitude and in fact to be continuous and 

 identical with the Algonquin beach north of Manistee. The Algonquin beach appears to come 

 to a horizontal attitude about at Herring Lake, where it is thought to pass into the same plane as 

 the Toleston beach. (See p. 356.) 



West and south shore of Lake Michigan hasin. — Except where it has been washed away by 

 the modern lake, the highest Algonquin beach has been identified and traced with almost com- 

 plete continuity along the entire western shore of Lake Michigan and around its south end (in 

 the southern half under the name of the Toleston beach). In the interval between Sheboygan, 

 Wis., and Cooks Mills on the northern peninsula of Michigan the writer made a reconnaissance 

 of the old shore lines in 1893, but this same district and the shore southward to Chicago has 

 been studied since that time in much greater detail, by Goldthwait in particular. Gold- 

 thwait's measurements and those of Hobbs on the Garden Peninsula were made instrumentally. 

 Farther south the beaches of Lake Chicago, including the Toleston (Algonquin) beach, have 

 been studied by Leverett, Alden, and Goldthwait, and their extent and relations to the Chicago 

 outlet have been fully determined. 



Ontario. — Detailed work and instrumental measurements have also been made in Ontario, 

 from Sarnia to the base of the Saugeen Peninsula at Wiarton and thence along the south side 

 of Georgian Bay, around Lake Simcoe, and on the Penetang Peninsula. These studies also 

 include the region of the outlet at Kirkfield and extend some distance clown the ancient Algon- 

 quin River. The earliest work in this region was clone by Spencer in 1887 and his measurements 

 were instrumental. Later, several studies of a somewhat desultory nature were made by the 

 writer. In 1908 an instrumental survey and further detailed studies were made by Goldthwait 

 and the writer. The highest Algonquin shore line is finely developed throughout this area and 

 the whole of the upper group is well displayed at many places, especially along the south side of 

 Georgian Bay and on the Penetang Peninsula. 



Lake Superior hasin. — On the north side of Lake Superior, from the international boundary 

 to Heron Bay, at the northeast angle of the lake, instrumental measurements of the shore lines 

 were made by Lawson in 1891. His work in all probability covers some of the Algonquin 

 ridges, but they have not yet been identified with certainty. 



Lawson also examined the slope north of Sault Ste. Marie, Ontario. At tins locality the 

 highest Algonquin and several heavy ridges below it are clearly identified as members of the 

 upper group. From the fact that it lies directly in the line of dip of the Algonquin water plane 

 through the Straits of Mackinac and down the east side of Lake Michigan, this locality is of 

 great importance. Since Lawson's work it has been visited by the writer and more recently 

 by Mr. Leverett, who found that all the beaches from the highest Algonquin down were finely 

 displayed. The Algonquin group is best displayed at Root River, 6 miles north of Sault Ste. 

 Marie and the highest strand is there 435 feet above Lake Huron. This locality overlooks the 



