Raised Beaches near Cleveland^ Ohio 
267 
and Cuyahoga river valleys. The arm of the lake extending 
southv^ard into the former valley was crescent shaped, the western 
being the shorter of the two segments; but the prevailing winds, 
by constructing spits and bars, gradually brought that part of the 
shore into alignment with the general direction of the beach. A 
more detailed discussion of this is given later. 
The valley of Big creek also formed a small bay during the early 
part of this lake stage; here again, on its western side, bars gradu- 
ally developed and straightened the shore line. 
The mature Cuyahoga valley was occupied by water of the 
Maumee level, reaching southward through the entire length of 
the Cleveland sheet. This arm was the drowned portion of the 
Cuyahoga valley, for the tributaries of which the lake constituted 
a local base level into which they spread deltas. 
The shore of the Lake Whittlesey stage shows no evidence of a 
bay in the meridian of Rocky river; there was a slight curve in its 
outline where the water fronted the lower part of Big creek. In 
the Cuyahoga valley, however, this stage appears to have extended 
southward through the Cleveland sheet; its altitude is recorded 
by terraces cut into the deltas of the preceding stage, as well as 
by the extension of these deltas during the existence of Lake 
Whittlesey. 
The Warren shoreline is characterized by but one embayment, 
that occupying the Cuyahoga valley which was ponded the entire 
length of the Cleveland sheet. 
THE DEVELOPMENT OF SHORE LINES. 
The processes involved in the development of shore lines are 
chemical and mechanical. The chemical factor is not of great 
consequence, though from one point of view it demands attention; 
the mechanical processes are really the ones that need considera- 
tion. Winds impel the water into waves and currents producing 
primarily two movements, on-shore and along-shore. The effective- 
ness of each movement is controlled directly by the velocity of the 
wind and the nature of the coast. 
The work accomplished by these agencies is influenced in the 
first place by the nature of the material which the waves are at- 
tacking; if the coast is rock it yields less readily than do uncon- 
solidated deposits; in the second place, by the profile of the beach 
