io8 Frank Carney 



The exact course of this l^each in the vicinity of Elvria can- 

 not be mapped, chiefly because of stream erosion. 



East of Black river. — From the river to the eastern side of the 

 sheet the Whittlesey level is marked by a continuous beach struc- 

 ture, the off-shore slope of which for much of this distance shows 

 steepening- by wave-work towards the close of the Whittlesey 

 period. 



Throughout most of this distance there is an inner beach ridge 

 of earlier development. About one and one-half miles west of 

 Nordi Ridgeville a third ridge appears. Locally these ridges indi- 

 cate greater activity of wave and along-shore work, thus piling up 

 heavy beaches and eventually moving the shoreline outward ; a 

 cross-section near the east side of the sheet (fig. 4 H) is an ex- 

 ample: a similar relationship of the two ridges exists west of Norch 

 Txidgeville near the second highway leading south. Locally the in- 

 ner ridge is lower (fig. 4 I) ; while in places a single beach exists 

 (%-4j). 



In the vicinity of Sheffield Junction I have mapped a spit that 

 grew to the northwest from the shoreline proper (fig. 2). This 

 spit, after it crosses the highway leading north to Lorain, has a 

 strong development. Following the decline of the Whittlesey level, 

 a marsh condition existed south of this ridge, as evidenced by the 

 extensive muck areas. The highway from this point to North Am- 

 herst formerly followed the ridge, having a more irregular course ; 

 later it was changed to its present more direct course across the 

 marsh. From the eastern end of this latter ridge the sandstone 

 forms a low escarpment, swinging southward to the shoreline 

 proper; that this escarpment is the result of wave-work is doubtful. 



Islands. — Several outliers of Berea sandstone formed islands 

 in Lake Whittlesey. One such area on the western edge of the sheet 

 eventually became a part of the shoreline itself, through being dou- 

 bly tied to the shore by bars, a feature that is observed on the next 

 sheet wesc, the Vermillion. A cliff in the sandstone nearly sur- 

 rounds the part of this island shown in the Oberlin sheet; a short 

 reach of structural deposits is found on both the north and south 

 sides of the island west of the wave-cut slope. 



Just east of North Amherst is another island of this lake stage 

 (^fife- 3)- T'l"'^ northern side of this is a wave-cut cliff; on the south- 

 ern side w^ave-cutting is also recorded, not in rock but in unconsoli- 

 dated material. A beach is found on the east side, with a spit 



