68 Transactions of the Canadian Institute. [vol. x. 



These four moraines, not including the Essex, are all land laid forms 

 so far as mapped, but all become waterlaid in the old lake bed south- 

 west of London. The same set of slender moraines occurs on the " thumb" 

 and in the Saginaw valley in Michigan. 



6. The Clinton Moraine. — As now known, this is a small fragment 

 of moraine lying west and northwest of Clinton. It is strongly developed 

 and stands high above the plain. It ends abruptly at the Bayfield river 

 and farther south was overridden by the Wyoming moraine. It pro- 

 bably continues some distance northward, but has not been mapped. 



7. The Wyoming Moraine. — This is one of the strongest moraines 

 of the series and in its relations to the other moraines one of the most 

 important. It is the continuation in Canada of the Port Huron moraine 

 in Michigan. As was stated above, this moraine marks a readvance of 

 the ice front after an exceptionally long step of retreat involving not 

 only greater distance, but probably also a much greater time than for 

 the average of the stadial oscillations. In Michigan and Wisconsin 

 this moraine is distinctly out of accord with the moraines that preceded 

 it. In Ontario its continuation in the Wyoming moraine stands in the 

 same relation. The Clinton moraine is a fragment of an earlier moraine 

 which has been overridden south of Bayfield river by the Wyoming 

 moraine. On the "thumb" in Michigan the Port Huron moraine over- 

 rides the Arkona beaches in the valley of Black river northwest of Port 

 Huron, and in Ontario, on the east limb of the same ice lobe, the same or 

 Wyoming moraine overrides some parts of the same beaches between 

 Arkona and Bayfield river. In both localities the Whittlesey beach is 

 contemporary with this same moraine, but the Warren (Forest) beach 

 is later and extends along the rear slope of the moraine.* About 7 miles 

 west of Port Huron and 4 miles west of Wyoming this moraine becomes 

 waterlaid and is low and inconspicuous in its relief. In this form it 

 crosses the St. Clair river just north of St. Clair, Michigan, and Court- 

 right, Ontario. Northeast of Wyoming to the Au Sable river it is stronger, 

 but is wide and of rather low relief. Farther north it presents a bold, 

 high front to the east along the west sides of the Au Sable and Maitland 

 valleys. Beyond this it is strong and exercises a pronounced control 

 over the drainage, especially on the courses of the Maitland and Rocky 

 Saugeen rivers. Between Whitechurch and Berkely it has not yet been 

 mapped in detail, but was seen near Walkerton and Hanover in early 

 reconnaissances. It is narrower, but quite definite and strong north- 



*A brief account of the glacial lakes, including Lakes Maumee, Arkona, Whittlesey, 

 Warren, etc., may be found in the report of the Smithsonian Institution for 1912. More 

 detailed descriptions will appear in a monograph of the U. S. Geological Survey, now 

 in prees. 



