Geography of Ohio 



99- 



Bays. Young shore lines are seldom even ; but the denuding 

 agencies of water tend always to straighten shore irregularities. 

 Ultimately the oceans, in case of no change of level of sea or land, 

 will change the most irregular shore line conceivable into an even 

 line. Lakes, being short-lived, probably never accomplish this 

 so perfectly. 



The indentations of lake shore lines are due to headlands which 

 represent the higher altitudes of the original stream-carved sur- 

 faces. Wave and current-work undercut and transport the de- 

 graded material of these headlands. The along-shore movement 

 of the water distributes the materials thus acquired. Such a cur- 

 rent, reaching a bay, is retarded both by the wave movement and 

 by the mass of water in the deeper part of the bay. The velocity 

 of the current being checked, its load is rapidly dropped. From 

 the angle of the bay this deposited material gradually extends into 

 deeper water ; such a deposit is called a "spit." As the spit grows, 

 a shallow water condition is maintained forward in the line of its 

 axis, and the transporting current is able to move farther, before 

 the on-shore movement of the deeper water in the baj- checks the 

 current and causes its load to drop. The influence of wave move- 

 ment, in the deeper parts of the ba}', manifests itself sometimes in 

 bending the spit inland, developing a "hook." Later the spit 

 may continue to grow in its original direction, and the hook will 

 then appear as an irregularity on the land slope of the spit. Fre- 

 quently a spit is developed also from the opposite side of the bay. 

 In time the two may grow together constituting a "bar." A bar, 

 however, seldom appears before the hsiy has been appreciably 

 shallowed. There is a constant current moving out from the ba}', 

 in case it receives a constant supply of land drainage. Such a 

 current keeps at least a narrow passage clear between the termini 

 of the spits. 



Spits are not always associated with bays. Sometimes such an 

 accumulation starts and grows outward from a headland or even 

 from the beach. 



Water isolated from the lake by the development of a spit or 

 a bar becomes a marsh. Vegetation gradually fills it in and the 

 tract is added to the land. Bays, when shut off from the lake, pass 

 through the marsh stage, at last becoming land. The abundant 

 vegetation of these marshy areas, sometimes forming peat swamps, 

 accounts for the muck soil found so extensivelv in the northwest 



