1905] BROWN—THE PLANT SOCIETIES AT YPSILANTI 265 
very steep, which rise to a height of some go feet above the water. 
The portion mapped is a fair type of the portion between Ypsilanti 
and Rawsonville, a village four miles southeast of the bayou. 
Throughout this part of its course the stream makes a number of 
loops and bends that would cause a boat to journey over ten miles 
to reach a linear distance 
of four. 
2. GEOLO HISTORY 
—The cemetery bluff, shown 
in the upper middle part of 
the map (p. 266) and also in 
ig. 1, is a portion of an old 
sand bar, “which trends 
north about a mile, and con- 
nects with a beach leading 
in from the west, which forms 
the continuation of the 
Western or main ridge found Fro. 1.—The cemetery bluff, shown in the 
south of the Huron River.’’? upper middle part of map; a portion of an 
This beach is one of two ancient sand bar. 
marking the northwest shore 
of Lake Maumee, which was the first of a series of large glacial lakes 
formed in this region with the retreat of the glacial ice. Later a 
change of outlet permitted the water to subside, forming Lake 
Whittlesey at a level some 75 feet below the upper Maumee beach. 
ning its existence this lake formed the well defined Belmore beach, 
weeting the river about three miles southeast of the bayou. Still 
farther subsidence of the waters brought about the formation of Lake 
aren, by whose waves the Forest beaches were made at levels of 
60 to 90 feet below the Belmore, and at a distance of more than 
seven miles further down stream. From this point there is a stretch 
of fixed sand dunes extending to within eight miles of Lake Ene. 
ee the Lake Maumee stages, ice and water had not yet 
vered the bayou area, except for high points of the sand bar. 
ring the Lake Whittlesey stage, the stream was cutting its first 
I i : 
er. F., Glacial formations and drainage features of the Erie and Ohio 
- S. Geol. Survey 41:chaps. 14-16. 
