378 PLEISTOCENE OF INDIANA AND MICHIGAN. 



uncommon heigth above the plain in front of it and generally with considerable height above 

 the land behind it. 



East of Ypsilanti the delta deposits made by Huron Kiver in Lake Maumee caused the 

 line of the beach to bulge about a mile eastward beyond its general course. Where the road 

 leading west from Denton crosses it, its front presents the characteristic bold relief. One to two 

 miles north of this point a finely formed spit was built out for about a mile across some low 

 ground west of the main ridge. Along the front of the delta the ridge is uncommonly strong, 

 and the height to which it rises above the delta plain back of it seems to indicate that the beach 

 was pushed up the slope slightly by the rising of the lake while it was being made. It is developed 

 in unusual strength at Plymouth in connection with the delta of Rouge River. At Birmingham 

 it is carried about 3 miles east of its general trend by the low, broad ridge of the Detroit inter- 

 lobate moraine. It continues thence in a direct line and in fine form and strength, passing a 

 mile east of Rochester, half a mile west of Washington, and 1J miles southeast of Romeo. A 

 bowldery, morainic tract 3 miles southeast of Romeo rose high enough to catch this beach, and 

 another small fragment occurs a mile farther east. Behind these outlying fragments the main 

 ridge is weaker, but toward Armada and thence southeastward to Richmond it is very strong, 

 standing out boldly not less than 20 to 25 feet above the plain in front of it and in some places 

 10 or 15 feet above the ground back of it. It is followed by the main highway of the region. 

 In sec. 33, Armada Township, it crosses the trench of a small creek like a high railroad embank- 

 ment 15 to 20 rods wide. The creek is trenched about 15 feet in the plain, above which the 

 crest of the beach ridge rises fully 25 feet. 



At Richmond the Whittlesey beach turns an acute angle and runs directly north to Memphis. 

 From the east bank of Belle River it runs northeast about 2 miles and after curving northwest 

 continues north and northeast in slightly reduced strength to Mill Creek, 1£ miles west of Avoca. 

 From this point it runs east and northeast to Spring Hill, where it seems to end in a bulblike spit 

 made up of several closely set beach ridges that turn their points back to the northwest. This 

 spit stands 12 to 15 feet above the plain all around it excepting toward the west, where a low 

 morainic ridge rises to its level. 



WHITTLESEY BEACH IN BLACK RIVER BAY. 



The gateway into Black River Bay of Lake Whittlesey was between Spring Hill and the 

 front of the main moraine of the Port Huron system at Zion, 3 miles to the east. Between 

 Spring Hill and Carsonville there are a considerable number of fragments of the Whittlesey 

 beach. They are all fragments, however, and are extremely irregular in their arrangement. 

 Most of them were simply bars in the shallow bay without any connection with the shore, and 

 all are on the western side of the deeper trough of the bay which runs northward along the east 

 side nearly to Applegate. (See fig. 5, p. 366.) North of Carsonville Black River Bay was so 

 shallow that wave action was ineffective and no distinct beach was found in the few accessible 

 places of that swampy district. 



Along the west side of the bay south of Carsonville no distinct shore line was found north 

 of a point opposite Buel, though several bars and beaches on islands are well developed farther 

 north in the western part of the bay. A beach is developed along the west shore both north 

 and south of Roseburg, but it is faint and fragmentary and fades toward the south at the 

 back of the wide flats northwest of Spring Hill. 



The east shore of Black River Bay was the front of the main moraine of the Port Huron 

 system or of the ice sheet while it was building that moraine. Between Zion and Applegate the 

 front of this moraine at the Lake Whittlesey level was carefully examined for shore lines but 

 nothing of a wave-made character was found; only a few small kames or gravelly deposits of 

 outwash and in one or two places fine sandy outwash that had been blown up into dunes. 



Some further description is needed to show the conditions in Black River Bay at the time of 

 Lake Whittlesey. At that time a relatively narrow trough of deeper water, with its western 

 margin marked by the upper of the three Arkona beaches, extended northward along the axis of 



