300 PLEISTOCENE OF INDIANA AND MICHIGAN. 



The most important of these transitory channels is a still later one which runs along the 

 base of the hills north of Verona Mills and, turning in a direction a little south of west, passes 

 just north of Bad Axe. This channel is a mile wide and is a well-marked scoured depression 

 with a bowldery floor. It was formed when the ice front rested on the ridge which runs along its 

 north side. This channel probably carried the whole discharge, leaving the Ubly channel dry. 

 At this time a long, narrow, shallow lake, running southeast from near Verona Mills into Sanilac 

 County, covered the flat ground between the ice front and the recently abandoned moraine. 

 This lake was not a part of Lake Whittlesey, but was an independent though very short-lived 

 body. During this same time two or three similar shallow lakes lay on the west side between 

 Bad Axe and Gagetown. The waters of all these channels and lakes finally reached Lake Sagi- 

 naw through the transverse channel from Gagetown to Cass City. 



At the last stage, however, the water appears to have taken a different course at the 

 southwest, for between Popple, Rescue, and Gagetown, and extending several miles farther 

 southwest, the inner slope of the latest ridge of the Port Huron morainic system is heavily cut 

 at or a little above the level of the Warren beach, making a steep bluff which extends for many 

 miles and seems much too great to be attributed solely to the waves of Lake Warren, especially 

 when it is noted that scarcely any other part of the Warren shore presents a wave-cut bluff. 

 It seems certain that during the last stand of the ice along this ridge the water, coming probably 

 from the Bad Axe spillways, found a temporary constricted passage between the ice and the 

 morainic ridge, and it was mainly the cutting of that stream that made the bluff. The gravels 

 gathered from this cutting were carried southwestward toward Vassar. Later the waves of 

 Lake Warren, working at nearly the same level, did some further cutting at the base of the 

 bluff, but this effect was probably not great, for at some places the waves did not reach the 

 bluff. At the same time, besides contributing considerable fresh gravel to the deposits near 

 Vassar, the waves worked over those previously deposited by the temporary river. The cutting 

 of the inner slope in this stretch is much like that which affected the Birmingham moraine at 

 Romeo. (Seep. 284.) 



BAY CITY MORAINE. 



Inside of the main moraine of the Port Huron system of the Saginaw basin and 10 to 12 

 miles nearer the lake runs another much fainter morainic belt known as the Bay City moraine. 

 Its faintness suggests that it is a subsidiary ridge of the Port Huron system, but it is all deeply 

 water-laid and its faintness alone is not a safe criterion. In its distribution it appears to be inde- 

 pendent, though it seems hardly likely that it marks a substage. 



A moraine which is doubtfully correlated with the Bay City moraine begins 5 or 6 miles 

 northwest of Tawas on a rugged slope of bowlder clay which forms a sort of retaining wall for 

 the south part of the great delta of Au Sable River. The moraine runs slantingly down the 

 slope from about 750 feet altitude to about 650 feet. From its top the edge of the delta extends 

 away north and northwest as a sand plain. The moraine is gullied by ravines that run down 

 the slope, but it seems to have had a swell and sag topography considerably modified by erosion. 



To the southwest for 5 or 6 miles this fragment gives place to a sandy country, but it may 

 be continued by a low stony till ridge which sets in close east of Turner and Twining in Arenac 

 County. This ridge trends southwest in direct line with other faint knolls, near Omer and 

 Standish, which clearly belong to the Bay City moraine. 



From this place the moraine continues southwest into Bay County, bending gradually 

 around to the south and southeast and keeping 5 to 8 miles from the shore, and crosses Saginaw 

 River at Bay City as a distinct though faint ridge. From Bay City it bends southeast 7 or 8 

 miles, passing around the south side of the swamps of Quannicassee. Then from the southeast 

 corner of Bay County it runs northeast through Tuscola County, keeping 5 to 6 miles from the 

 shore and passing Fairgrove and Unionville. In southwestern Huron County it is weaker, but 

 it reappears in fair strength 4 miles north of Elkton, beyond which it is represented by an 

 ill-defined bench and a bowldery belt, which runs northeast through Meade Township into 

 eastern Dwight Township and then swings southeast through Huron Township. A shore line 



