760 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



River and Cleveland by A. A. Wright, while the portion between Cleve- 

 land, Ohio, and Cattaraugus Creek in New York has long been known to 

 the geologists who have made investigations in that region. Fairchild 

 has continued the examination of the Warren shore from Erie County, 

 N. Y., eastward beyond the Genesee River, as indicated below. The outlet 

 of Lake Warren appears to have been westward from Saginaw Bay through 

 Spencer's " Pewamo Strait"' to Lake Chicago, in the southern end of the 

 Lake Michigan Basin, and thence through the Chicago outlet to the Illinois 

 and Mississippi rivers. But as this, as well as the part of the beach in Mich- 

 igan, is soon to be made the subject of further study, a description will not 

 be attempted in this place. 



DESCRIPTION OF THE BEACHES. 



The portion in Ohio north of Maumee River is reported by Gilbert to 

 be a broad belt of sand, chiefly in the form of dunes but nearly level on 

 the inner margin. The altitude of the sand extends from about 90 feet 

 above Lake Erie down to 60 feet, or even lower. The western border leads 

 from the Ohio-Michigan line near Sylvania southwestward to Napoleon. 

 Gilbert remarks that the border is not so definite as it would need to be to 

 admit of easy mapping, but stands near the line just indicated. The inner 

 border of the sand belt touches the Maumee for a short distance just above 

 Toledo, but for several miles farther it lies 2 or 3 miles back from the river, 

 after which it again extends to the river. 



Sherzer's studies, which have been extended southward from Michigan 

 a short distance beyond the State line, have brought to light a range of 

 sand ridges standing between 650 and 660 feet, which he considers the 

 Forest beach. This range has not been examined by the writer, but upon 

 inspection of the Toledo topographic sheet it is found that the rise is quite 

 abrupt between the 640 and 660 foot contours, as if the lake had cut back 

 its shore there. 



In the district between the Maumee and Sandusky rivers there are 

 several conspicuous ridges of sand and belts of dunes whose altitude is 

 more than 100 feet above Lake Erie. The plains on the border of these 

 ridges have generally an altitude about 100 to 115 feet above the lake, or 

 670 to 685 feet above tide, and the main lake level appears to have been 



1 Am. Jour. Sci., 3d series, Vol. XLI, 1891, p. 207. 



