112 RURAL MICHIGAN 



hearth furnaces and in the manufacture of paper by 

 the sulfite process, are mainly employed as road 

 material and railway ballast, while building stone is 

 thus derived in Monroe County. Still other quarries 

 of limestone are in Eaton, Wayne and Huron coun- 

 ties, which are valued because situated in areas where 

 outcrops of rock are seldom encountered suitable for 

 quarrying. Eecently there has been a tendency to 

 employ the high calcium limestones in the North as 

 a soil corrective, for which they are well adapted. 

 Near Ishpeming is a formation of marble, designated 

 the "verde antique," which yields a greenish marble 

 barred with white bands of dolomite, which when 

 polished is extremely beautiful. This marble area 

 is now being commercially exploited. In the south- 

 ern peninsula limestone is employed in the manu- 

 facture of concrete, as noted in another paragraph. 

 The value of limestone produced in Michigan in 

 1917 is stated by the State Geological Survey to have 

 been $3,320,895.^ In 1918 the United States Geo- 

 logical Survey ranked Michigan sixth in the pro- 

 duction of limestone.- The product in that year 

 was 134,813 tons, valued at $8.80 a ton. The Geo- 

 logical Survey notes that the demand for building 

 lime had declined almost to the vanishing point.^ 

 In 1917 Michigan produced 236,612,000 common 

 bricks, which represents a decrease from the output 



^See Kept, on Mich. Limestones in "Production and 

 Value of Mineral Products in Michigan," Lansing, 1915, 111. 

 2 "Lime in 1918": U. S. Geol. Survey, p. 817. 

 Ubid., 822. 



