LIMESTONE AND DOLOMITE 



363 



Table 70. — Principal sources and some potential sources of high-purity dolomite in the United States 



Stratigraphic unit 



Principal areas of occurrence of 

 hierh-purity dolomite 



Eastern and Central United States 



Devonian 

 Silurian . 



Ordovician 

 Cambrian _ 



Mississippian 



Devonian 

 Silurian . 



Ordovician 

 Cambrian 



-Geneva Dolomite Southeastern Indiana. 



-Niagara Group, Lime- Wisconsin, Illinois, Michigan, Indiana, 



stone, or Dolomite. Ohio, Pennsylvania, New York. 



-Galena Dolomite Northern Illinois. 



-Tomstown Formation Western Maryland, western Virginia, and 



eastern panhandle of West Virginia. 



Shady Dolomite Eastern Tennessee, southwestern Virginia. 



Ketona Dolomite Northern Alabama. 



Western United States 



-Monte Cristo Dolomite or Southern Nevada. 

 Limestone. 



-Water Canyon Formation Northern Utah. 



.Laketown Dolomite Southeastern Idaho, northern Utah. 



Fusselman Dolomite South-central and western New Mexico. 



.Bighorn Dolomite or Western Wyoming. 



Limestone. 



Fish Haven Dolomite Northern Utah. 



.Hasmark Formation or Western Montana. 



Dolomite. 

 Royer Dolomite Southern Oklahoma. 



contain deposits having exceptionally high calcite 

 content — the Holston Limestone of eastern Tennes- 

 see, the Valentine Member of the Curtin Formation 

 of central Pennsylvania (one of the purest lime- 

 stones in the United States), and the New Market 

 Limestone of western and southwestern Virginia. 

 In the eastern panhandle of West Virginia, the 

 Tomstown Formation contains units of high-calcium 

 limestone and high-purity dolomite, both of which 

 are intensively exploited. The chief source of high- 

 purity dolomite in the United States is the Niagara 

 Group (table 70) in western Ohio. 



PROBLEMS FOR RESEARCH 



Although the United States is self-sufficient in 

 limestone and dolomite and reserves of these rocks 

 are immense, the reserves of chemically pure lime- 

 stone and dolomite are limited and decreasing be- 

 cause some deposits are being mined out, users con- 

 tinue to make more stringent specifications, land 

 underlain by high-purity carbonate rocks is being 

 preempted for other uses, and zoning regulations 

 restrict or prevent quarry operations in populous 

 areas. The cost of high-calcium limestone will in- 

 crease as thick, near-surface layers close to the in- 

 dustrial centers are mined out. Future production 

 increasingly will depend on selective mining of rela- 

 tively thin layers of limestone, underground mining, 

 and mining from deposits distant from industrial 

 centers. High-calcium limestone resources are more 

 endangered by urban spread than almost any other 

 mineral resource, except perhaps for sand and 

 gravel, and the need to identify and protect areas 

 of high-calcium limestone for future use is pressing. 



Future supply of high-purity dolomite in the 



United States is less of a problem than that of 

 high-calcium limestone because far less high-purity 

 dolomite is required by industry. Furthermore, im- 

 mense resources of high-purity dolomite occur in 

 the Great Lakes region, near eastern industrial cen- 

 ters where most dolomite is used. The extensive 

 high-purity dolomite of the Niagara Group (table 

 70) is an example. Resources of high-purity dolo- 

 mite in the United States should be adequate for 

 thousands of years. Shipping costs will continue to 

 be a major factor in the future sources of supply 

 of high-purity limestone and dolomite, particularly 

 in the Western United States. These costs will rise 

 as more distant sources are exploited, which prob- 

 ably will bring about the use of less pure stone 

 nearer the user. 



Although much general information about po- 

 tential resources and distribution of chemically pure 

 limestone and dolomite in the United States is avail- 

 able, detailed information about the chemistry and 

 the distribution of high-quality stone in most forma- 

 tions is relatively sparse. Systematic study of these 

 formations should be undertaken to identify favor- 

 able areas that can be protected from urban spread 

 and thus assure an adequate supply of inexpensive 

 stone in the future. 



SELECTED REFERENCES 



Boynton, R. S., 1967, Chemistry and technology of lime and 

 limestone: New York, Intersci. Pubs., 499 p. 



Chilingar, G. V., Bissell, H. J., and Fairbridge, R. W., eds., 

 1967a, Carbonate rocks — Origin, occurrence and classifi- 

 cation, [v.] 9 A of Developments in sedimentology : New 

 York, Elsevier Publishing Co., 471 p. 



1967b, Carbonate rocks — Physical and chemical as- 

 pects, [v.] 9B of Developments in sedimentology: New 

 York, Elsevier Publishing Co., 413 p. 



