228 Frank Carney 



part of Ohio. During all three of the ice-front lake stages, the 

 Maumee valley, which always had a very low slope towards the 

 axis of the Lake Erie basin, contained a bay. The shallowness of 

 the bay encouraged the growth of spits and bars, converting 

 successive parts of it into a marsh. This history was repeated 

 during the Maumee, Whittlesey and Warren stages. As a result 

 there were deA^eloped in that part of Ohio hundreds of square miles 

 of muck land, much of which had to be artificially drained by the 

 early settlers. This land is very rich, and when brought under 

 cultivation makes profitable farms. Smaller muck areas are found 

 the whole length of the shore lines of these three lakes. 



Other shore line structures. Along the lake front one sometimes 

 sees a deposit of sand and gravel, growing directly out into the 

 lake. This product of deposition, called "a cusp," is due to the 

 interference of waves and currents, causing a deposition of the 

 load in transit. As the cusp grows, the interference area is in- 

 creased, and the deposit is extended more rapidly; but upon 

 reaching deeper water it makes little progress. After attaining 

 some size, bordering barriers may develop, and later be tied to the 

 cusp. By this process, a lagoon is formed between the cusp and 

 the barrier ; it passes through the regular lagoon history, and thus 

 increases the cusp's area. By a repetition of this process, as well 

 as by extensions made similarly through the development of 

 spits, the cusp attains large proportions, and is then called a 

 ''cuspate foreland." 



Especially along shallow shores, the larger waves break a con- 

 siderable distance from the coast. The wave "breaks" because its 

 diameter or height is greater than the depth of the water. Along 

 the line where "breakers" form, the action tends to pile up the 

 material at the bottom. This process eventually develops a ridge 

 on the bottom that in time shallows the water sufficiently to catch 

 even the smaller waves. With the lapse of more time, the ridge 

 appears above water as a line parallel to the coast proper. In 

 reality it is a new beach, and is called a "barrier beach." When 

 barrier beaches persist, they are usually connected with cusps or 

 headlands in such a manner as to isolate the water between them 

 and the original shore. This creates a marsh which passes through 

 the various lagoon stages. The barrier beach then becomes a 

 shore ridge. 



Rivers flowing into a lake have their velocity checked by the 



