208 J. W. Spencer — High Level Shores of the 



and forms the broad flat plains at the head of Saginaw Bay. 

 But these plains, for half their length, are drained to the west 

 by the Grand River, although they were "formerly the floor of the 

 lately enlarged Saginaw Bay. Hence, the topography shows 

 the reversal of the drainage, by a slight uplift towards the east 

 and north, which in the region of Pewamo amounts to about a 

 foot per mile. This rise continues to Chapin, whence the 

 beach rises towards the northeast and passes around the thumb 

 of Michigan, and descends to about a mile east of Emmett. 

 From the crossing of the beach, east of Ypsilanti, to Lenawee, 

 there is no terrestrial warping as shown by instrumental 

 measurements. The occurrence of this beach, although not 

 identified throughout any distance, was described by Prof. A. 

 Winchell.* From Lenawee, the Pidgeway Beach extends into 

 Ohio, and becomes identical with the beach of the Maumee 

 Valley, called by Mr. Gilbert number three. f Thence it 

 extends eastward with natural interruptions. From Ohio it 

 has been traced into New York by Mr. Gilbert. The portion 

 south of the western half of the lake practically shows no 

 deformation, but between Madison and Sheridan Centre, it 

 rises about a foot per mile, while the lower, or Forest Beach 

 rises in the same distance only about three quarters of a foot, 

 although eastward of that point the last named beach rises two 

 feet per mile. 



At the head of the Maumee valley, a fragment of a beach, 

 about thirty feet higher than the Pidgeway Beach, was de- 

 scribed in the Geology of Ohio.J This, however, is only occa- 

 sionally met with. A beach at Grand Papids, Mich., at 700 

 feet, and a terrace near Allegan at 689, may be the equivalent 

 of that in Ohio. 



The Maumee Beach. — This is the next highest of the well 

 defined beaches which have been studied. That, at 42 feet 

 above the lake at Chicago, is probably identical with the beach, 

 which has been traced from the southeastern side of the lake, 

 as it is in the topographical position in which we would expect 

 to find it. But the country is a very sandy and duny. 



The beach is identical with Mr. Gilbert's number one at the 

 head of the Maumee valley, and hence the suitability of the 

 name. When the water was at this level, Mr. Gilbert regarded 

 the outflow of the lake as by the Wabash River. The divide, 

 at the head of this river, from the Maumee drainage was 

 nearly fifty feet below its surface. § But it was not then known 

 that this deserted shore extended throughout the Saginaw val- 

 ley to the Michigan basin. Nor had the moderately complete 



* Geology of Washtenaw County, by A. Winchell, 1881. 

 f. Geology of Ohio, map, p. 549. % Ibid. 



§ Geology of Ohio, vol. i, p. 551. 



