230 Frank Carney 



interval between the beaches is divided between either shore. 

 Where the beach ridges are a mile or less apart, the farms usually 

 are narrow. Wherever sufficient muck land exists, and the area 

 is within easy reach of a city, the farms are small; they are culti- 

 vated intensely, usually by market gardeners. 



These ridges usually furnish the sand and gravel needed for 

 structural purposes and for roadbeds. As concrete comes more 

 generally into use, the economic advantage of the old shore lines 

 will be even better appreciated. In several locations the material 

 is adapted to the manufacture of sand brick; elsewhere I have 

 seen the lake clays being used for tile, and for various other kinds 

 of brick. 



Quite a variety of soil is associated with these shore lines. The 

 local rocks have had a great deal to do in determining the soil. 

 In the region south of Sandusky, the denudation work of waves 

 on the outcropping limestone has accumulated great areas of 

 very clear silica, or sand. This silica existed in the limestone; 

 the carbonates were entirely dissolved. In these areas peach 

 orchards do well ; melons and other vines appear also to thrive on 

 the rolling sand hills. 



The botanist has long been acquainted with the shifting facies 

 of plant habitats, bordering shore lines. Even to-day one finds 

 all the plant families within the limits of a bog habitat on the 

 one hand, and a very dry sand dune on the other. 



Post-glacial tilting. A shore line should be horizontal. If it 

 is not horizontal, it has suffered tilting since it was made. Beaches 

 of nearly all the ice-front lakes show deformation. This is not 

 noted appreciably across northern Ohio, but the beaches of the 

 same lakes when traced into Michigan or into New York do show 

 tilting. The axis of movement was such that it is not so manifest 

 in northern Ohio. It is possible, however, that a closer study of 

 our shore lines may show that they are not horizontal. One ap- 

 preciates why it is not an easy matter to tell exactly the water 

 level of a shore line which has been subject to subaerial weather- 

 ing for several thousand years; if it is a cliff cut in rock, it has 

 suffered less change, and more accurate definition is possible. 

 Up to date no one has gathered data that establish much infor- 

 mation of the high-level lake beaches across Ohio. In New York 

 state some of these ancient strands have been very appreciably 

 tilted. In the first one hundred and twentv-five miles of direct 



