117. 



throughout Ohio and its character is known only from wells, of which 

 more than 3,500 have been drilled through it. The salt thins westward 

 and disappears beyond a line extending from Lorain, on Lake Erie, to 

 Marietta, near the Ohio River. Over most of this area the salt beds 

 have an aggregate thickness of more than 100 feet. The maximum is 

 reached near Canton, Stark County, where well logs indicate the pres- 

 ence of several beds with an aggregate thickness estimated at more 

 than 200 feet. Along Lake Erie, recent borings for the purpose of 

 prospecting the salt beds indicate that their thicknesses total 60 to 70 

 feet in Cuyahoga, Lake and Ashtabula counties. 



Near the Pennsylvania line, in Ashtabula County, the salt occurs at a 

 depth of about 2,300 feet below the water level of Lake Erie. The 

 depth decreases westward to a depth of about 1,300 feet near Lorain. 

 From Lake Erie the beds dip gently southward. At Barberton, about 

 40 miles south of Cleveland, the uppermost salt is at a depth of 2750 

 feet. In Harrison County, 50 miles farther southeast, the salt was 

 reached at over 4700 feet. The total area in Ohio underlain by salt de- 

 posits is over 15,000 square miles. Figure 4 shows the area in Ohio 

 underlain by rock salt and the depth below sea level of the top of the 

 salt. 



3.5 Michigan has the largest reserves of salt of any state. Rock salt 

 underlies most of the state, within the Michigan basin. It is found in 

 the Salina formation, which is deposited in a saucer-like form, taper- 

 ing toward the margins of the basin, where it is overlapped by younger 

 formations and does not appear at the surface. Brine is found in sev- 

 eral other formations.'"' 



In the southeastern part of the state, along the Detroit River, the 

 aggregate thickness of rock salt is from 200 to 500 feet. The thick- 

 ness increases northwestward into the basin. In Bay County, about 90 

 miles northeast of Detroit, a maximum thickness of 1800 feet of salt 

 was penetrated. Around the periphery of the basin, the salt thickness 

 generally increases down dip from at the edge of the Salina wedge to 

 a thickness of 1000 feet in about 50 miles. 



In Wayne County, near Detroit, the depth to the first salt bed ranges 

 from 800 feet at Ecorse to 1150 feet at Oakwood (Detroit) and over 1600 

 feet at Port Huron. On the west si.le of the basin, near Ludington and 

 Manistee, the salt has been reached at depths of about 2000-2300 feet. 



The total area of the southern peninsula of Michigan that is probably 

 underlain by salt-bearing formations is 35,000 square miles. The 



