310 PLEISTOCENE OF INDIANA AND MICHIGAN. 



by W. C. Alclen and the writer in the moraines in eastern Wisconsin during a field conference 

 in September, 1910. The moraine leading north from Two Rivers has no beach higher than the 

 third beach of Lake Chicago, which is there about 25 feet above Lake Michigan. But within a 

 few miles south of Two Rivers, on the plain between the lake and one of the earlier red drift 

 moraines, beaches and river deltas are developed up to about 60 feet above Lake Michigan. 

 There could scarcely be better grounds for correlation than are presented in the relation of these 

 moraines to the Lake Chicago beaches. 



ISLANDS IN THE NORTHERN PART OP LAKE MICHIGAN. 



Several prominent islands lie some miles off the eastern shore of Lake Michigan, the largest 

 being Beaver Island and the two Manitou islands. The Fox Islands he between these, and 

 several other islands he near the north end of Beaver Island. North and South Manitou and 

 Beaver islands carry heavy accumulations of drift with morainic surface. The other islands are 

 more largely formed of sand, and those near Beaver Island have slight outcrops of rock. North 

 Manitou Island has two high rugged north-south morainic ridges which merge at the southern 

 end of the island but are separated by a low tract containing a lake near the northern end. 

 Much of South Manitou Island is somewhat less prominently morainic. Mr. Taylor reports that 

 on Beaver Island morainic ridges trend northwest and southeast in the north and southeast 

 parts of the island, as if formed by ice from the east, but that an area of seemingly inter- 

 lobate deposition with basins and ponds hes to the southwest. All these island moraines are 

 probably later than those formed on the mainland unless the moraines on Beaver Island correlate 

 with the Cheboygan moraine- of the Huron lobe. Correlation across such wide strips of water is 

 very uncertain, and the morainic features of the islands will be left with tbis passing notice. 



DRUMLINS IN THE GRAND TRAVERSE AREA. 



Distribution. — Drumlins are best developed in the district between Grand Traverse and 

 Little Traverse bays, though a few well-developed drumlins and numerous drumlinoidal hills 

 Me west of Grand Traverse Bay and a few drumlinoids north of Little Traverse Bay near 

 Leveling. Drumlins occur for about 25 miles inland from the borders of Lake Michigan and at 

 all altitudes from 20 feet up to 300 feet above the level of the lake, or from 600 to about 900 feet 

 above sea level. They are confined almost entirely to the uplands and slopes, though near Elk 

 Rapids some were found on the low plain bordering Elk Lake. At the southeast border of the 

 district the drumlins are closely associated with morainic knolls, and in places may be said to 

 grade into- them, some hills having a well-rounded drumlin form at their northwest end and a 

 hummocky topography at their southeast end. Features of this sort are found on each side of 

 the southern part of Pine Lake, and also on the borders of the south end of Intermediate Lake, 

 both east and west of Bellaire, and thence northeastward toward the south arm of Pine Lake. 

 From Pine Lake to Little Traverse Bay a gradual change takes place from well-defined drumlins 

 to drumlinoidal ridges and then to elliptical but irregular-surfaced hills such as immediately 

 border the city of Petoskey. The drumlins show their most characteristic form in the district 

 between Pine Lake and Torchlight Lake. (See fig. 2.) Most of the ridges between Torchlight 

 Lake and Grand Traverse Bay, as well as those on the peninsula in the bay and on the peninsula 

 between Grand Traverse Bay and Lake Michigan, are drumhnoids rather than true drumlins, 

 their shapes being very imperfect and then surfaces but slightly smoothed. They are, how- 

 ever, similar in trend and in general shape to the well-formed drumlins and are separated from 

 each other by the smooth sags generally present among drumlins. 



The drumlins vary in shape from oval forms, whose length is about one and a half times 

 their width, to linear ridges, whose length is six to eight times as great as the width. (See figs. 2 

 and 3.) The great majority, however, are one-half to three-fourths mile long and one-eighth 

 to one-fourth mile wide. The longest reach 1£ miles. Some large drumlins have fluted 

 slopes and resemble a small drumlin perched on a sculptured large one. Such forms are to be 

 seen on the borders of the south arm of Pine Lake (fig. 3) and in the district between Torch- 



