I 84 LOWER PENINSULA. 



Grant & Co.'s Salt Well, East Tavvas, Iosco Co., Michigan. 

 Depth of well, 905 feet. Salinometer, 85°. 



Sulphate of lime (gypsum) 0.0350 



Chloride of calcium 3-4843 



" magnesium 1-2433 



" sodium (salt) 1 5.6141 



Saline matter 20.3767 



Water 79.6233 



100.0000 



The analyses of these brines show a marked increase in the earthy 

 chlorides, and are without doubt from a lower saliferous horizon, 

 located in the Devonian strata, and consequently intermediate be- 

 tween the Onondaga formation and the Michigan salt group — this 

 same formation having been struck at Caseville, Huron County, 

 at the depth of 1750 feet, and at Blackmar's Mills, 13 miles east of 

 East Saginaw, at the depth of 1675 feet. The new wells going down 

 at Oscoda, Mich., are without doubt in this formation also. 



Composition of brines taken from wells on the Lake Shore of 

 Huron County, and representing an excellent quality of brine for 

 salt manufacturing — nearly approaching the Goderich brines in 

 freedom from the earthy chlorides : 



Sand Beach Well, Huron County. Depth of well, 702 feet. 

 Brine, 84° salinometer. Analysis by Dr. S. P. Dufifield. 



Sulphate of lime (gypsum) 0.2539 



Chloride of calcium 0.3000 



'^ magnesium 0.1591 



" ' sodium (salt) 22.5673 



Saline matter 23.2803 



Water 76.7197 



100.0000 



White Rock Well, Huron County. Depth of well, 566 feet. 

 Brine, 78.5° salinometer. 



Sulphate of lime (gypsum) 0.2623 



Chloride of calcium 0-5373 



