374 PLEISTOCENE OF INDIANA AND MICHIGAN. 



ice-border drainage which came from the east along the front of the ice sheet while the ice front 

 rested on the Alden moraine. The moraine stands about half a mile north and northwest of 

 the termination of the Arkona beaches and the general crest of the moraine is at about the same 

 level, with several knobs rising higher. The moraine runs west-southwest to the shore of 

 Lake Erie, 5 or 6 miles south of Buffalo. When the ice rested here during the time of Lake 

 Whittlesey, a long, narrow bay, 5 miles wide at Orchard Park, ran northeast between the ice 

 and the land for 20 miles. The Arkona beaches, submerged under the waters of this bay, were 

 well protected. The upper Arkona ridge at Alden has an altitude of about 865 feet. At Maxilla, 

 a few miles to the southwest, its altitude is about 850 feet, and that of the fading Whittlesey 

 beach is a little more than 900 feet. The situation here is the same as in the Black River valley 

 in Michigan, except that the New York area is small and is not so distinctly inclosed and protected. 



ARKONA BEACHES IN ONTARIO. 



The Arkona beaches were observed and their altitudes measured by Spencer at several 

 places in Ontario. In one area on the east side of the south arm of Lake Huron they have been 

 studied by the writer in almost as much detail as in southeastern Michigan. Two of them occur 

 at the village of Arkona on high ground that projects northwest. The ice, readvancing to build 

 the Port Huron morainic system, came close to this point and obliterated the beaches for a 

 few miles but did not disturb those in the long stretch of the valley of Au Sable River to the 

 east and north. In this valley two Arkona beaches are finely developed from the vicinity of 

 Ailsa Craig northward to a point west of Clinton, where they disappear under outwash. 



The conditions here almost precisely duplicate those in the Black River valley north of 

 Spring Hill but were not quite so favorable in providing protection and preservation, because 

 the mouth of the Au Sable at the time of Lake Whittlesey was wider than that at Spring Hill 

 and the heavy seas rolled into the valley with greater variation of direction and probably with 

 greater power. In the Au Sable Valley only one of the Arkona beaches is strikingly strong and 

 well preserved, but this one is truly remarkable. Some faint traces were found of a third beach 

 which probably belongs to the Arkona group. In that part of the Au Sable Valley between 

 Arkona and Ailsa Craig, the Au Sable has meandered right along the line of the best-preserved 

 Arkona beach. Some detached gravel deposits which look like fragments of a beach ridge 

 and occur in suggestive alignment and constancy of level probably represent the continuation 

 of the stronger ridge westward, but the evidence for the beaches west of Ailsa Craig is rather poor. 

 If the beaches of the Black River valley did not exist those of the Au Sable Valley in Ontario 

 would be regarded as truly remarkable. They point to precisely the same conclusions as to the 

 formation of the Arkona beaches before the building of the main moraine of the -Port Huron 

 system and the Whittlesey beach, and they show that the ice readvanced to the Port Huron 

 system, burying the Arkona beaches north of a point west of Clinton and causing those 

 south of that point to be submerged but preserved, in precisely the same way as in the Black 

 River valley. Along the east side of this valley the Whittlesey beach occurs in the same relation 

 as in Michigan, but lacks something of the strength and unique character shown there. 



South of the village of Arkona, two Arkona beaches are readily traced as far as Watford, 

 where they turn eastward. In this interval they were exposed openly to the sweep of heavy 

 Whittlesey storm waves from the west and southwest and were modified just as were those in 

 Michigan, though they were in few places rendered so faint as between Lenox and Spring Hill. 



The Arkona beach is mentioned by Spencer in two or three localities farther east, but no 

 further observations on it have been made as yet by the writer. In still another locality, 

 which has not yet been investigated, these beaches will probably be found in a good state of 

 preservation — submerged and protected but not overridden. This area lies north and north- 

 west of Copetown. 



