TRIBUTARIES OF LAKE ERIE. 215 



ville, the stream is given an easterly course for a few miles by a beacli line 

 which lies on its north side. Upon breaking through this line it passes 

 directly toward the lake. 



ASHTABULA CREEK. 



Ashtabula Creek is a small stream which enters Lake Erie near the 

 city of Ashtabula, in northeastern Ohio. Its source is in a morainic belt or 

 elevated uplands near Andover, Ohio, from which it flows northward 

 through a preglacial valley or drift-filled depression to lowlands bordering 

 Lake Erie. It there is deflected westward a few miles by a morainic 

 ridge, but breaks through this ridge near Ashtabula and takes a direct 

 course into Lake Erie. Its lower course is through a narrow valley cut in 

 shale to a depth of 75 to 100 feet, and is evidently independent of pre- 

 glacial drainage lines. The drift-filled depression which it follows in its 

 upper course was probably occupied by a preglacial stream that headed 

 farther south than the present divide, but the precise position of the old 

 divide has not been determined. 



GRAND RIVER. 



Grrand River is a small stream draining the basin from which it receives 

 its name (see p. 74). Its northerly course is through the former outlet 

 of the old Mouongahela drainage system, and, like Conneaut and Ashtabula 

 creeks, it is diverted westward near the border of Lake Erie by a morainic 

 ridge running parallel with the lake shore. This morainic ridge holds 

 the stream in. a westerly course nearly to its mouth at Painesville The 

 preglacial stream which discharged through the Grand River Basin came to 

 the present shore of Lake Erie a few miles west of Ashtabula, near the 

 village of Geneva. Grand River, like Conneaut Creek, encounters rock 

 strata throughout much of its westward course, and there flows in a naiTOw 

 gorge, strikingly in contrast with the broad, shallow valley of the Grand 

 River Basin. 



CHAGRIN RIVER. 



Chagrin River has two headwater forks, each of which finds its source 

 in marshes among the knolls of an interlobate moraine, on the elevated 

 upland east of the Grand River Basin. The two streams unite near Chagrin 

 Falls, above which point the valleys are inconspicuous. At the falls there 

 is a descent of a few feet over sandstone ledges. The stream then soon 



