588 PROCEEDINGS OF THE PHILADELPHIA MEETING 



retained lake Whittlesey. The outlet of the lake was through the Ubly channel, 

 close along the frontal base of the moraine, in the angle where it laps around the 

 crest of the thumb. In Wayne county the Belmore beach is 738 to 740 feet above 

 sealevel, and the Arkona beaches— three in number— are close to 708, 702, and 696 

 feet. 

 The principal evidences may be summarized as follows : 



1. The Belmore beach was not found on the back or iceward slope of the Port 

 Huron-Saginaw moraine ; neither is there any distinct beach, but only scattered 

 fragments of outwash at the Belmore level on the frontal slope of the moraine. 



2. The Arkona beaches are below the Belmore level and too low to connect with 

 the Ubly channel, and yet there is no sign of any of them on either slope of the 

 moraine. This shows that the Arkona beaches antedate the moraine and were not 

 formed after the fall of lake Whittlesey. On the other hand, the Upper Forest 

 beach, which lies next below the Arkona ridges, was found strongly developed on 

 both slopes of the moraine and is the highest shoreline recorded on it. This beach 

 passes around the end of the thumb into the Saginaw valley. 



3. Lake Whittlesey terminated at the north in a shallow, rather narrow bay 

 nearly 50 miles long. The entrance to this bay was northeast of Avoca, between 

 Spring hill and the moraine 4 miles east. South of this bay, where the heavy 

 seas of lake Whittlesey swept over the submerged Arkona ridges with full force, 

 these ridges show unmistakable evidences of modification. They are so flattened 

 that they are more easily traced by characters of composition than by their relief 

 as ridges. The soils on them and on the river deltas associated with them are 

 clayey and stiff as compared with the soils of the Belmore and Maumee beaches. 

 While the ridges appear in fair strength at some points south of Avoca, they are 

 in general very faint and hard to trace. They were almost washed away and de- 

 stroyed during the time of submergence. 



4. North of the entrance to the bay at Spring hill the three Arkona ridges un- 

 dergo a complete change of character. Within a mile or two they grow strong 

 and fully equal to the best development of the Maumee beaches and almost equal 

 to the Belmore. They are 100 to 400 feet wide at their bases and 6 to 10 feet high. 

 Fragments of the lower ridge were found on the east side of Black river and with 

 the foot of the moraine resting directly against their bases, leaving only a narrow 

 depression, 4 or 5 feet deep, between. In two or three paces one may step from 

 the sandy gravel of the beach to the stony clay of the moraine. These fragments 

 have almost no lake sediment or outwash on them, though farther north all three 

 ridges are buried under fine sandy outwash from the moraine. The lower ridge 

 was traced 6 miles north from Spring hill, the middle ridge 14 miles, and the 

 upper ridge 18 miles. These beach ridges could not have been formed in their 

 present surroundings. The massive moraine east of Black river and the glacier 

 which made it could not have been present. The ice-front must have stood several 

 miles farther north and east. It seems plain that the Arkona beaches antedate 

 the moraine. 



5. The Arkona beaches appear to have been made by a lake which was falling 

 by stages. The Belmore, on the other hand, gives evidence of having been made 

 by a rising lake, for its material appears to have been shoved up the slope while it 

 was being built. The Belmore beach appears to rest on a drift surface which was 

 previously trenched by streams. Where the Arkona ridges lay in the bay north 

 of Spring hill they were protected from disturbance by heavy seas, and such parts 



