360 



CEMENTS, LIMES, AND PLASTERS. 



beds quite different in composition. They are consequently worked 

 as separate benches or levels, temporary tracks being run in on the 

 upper levels, while the main switch tracks are on the lowest level. 



Examination of clay deposits. Most of the notes in relation to 

 examining limestone deposits presented on an earlier page will apply to 

 the report on a deposit of clay or shale. In sampling, however, the earth- 

 auger can be used much more extensively, as the clayey materials are 

 usually soft enough to be bored readily by such means. For valuable 

 notes on the use of the auger, reference should be made to the papers 

 cited below.* 



List of references on clays and shales. The literature of clays is 

 so extensive that the descriptive papers in the following list have been 

 arranged by States in alphabetical order. 



GENERAL UNITED STATES. Ries, H. The clays of the United States east of 



the Mississippi River. Professional Paper 

 No. 11, U. S. Geological Survey, 289 pp. 1903. 



ALABAMA. Ries, H., and Smith, E. Preliminary report on the clays 



of Alabama. Bulletin 6, Alabama Geological Survey, 

 220 pp. 1900. 



ARKANSAS. Branner, J. C. The cement materials of southwest 



Arkansas. Trans Am. Inst. Min. Engrs., vol. 27, 

 pp. 42-63. 

 Branner, J. C. The clays of Arkansas. Bulletin No. , 



U. S. Geological Survey. (In press.) 

 CALIFORNIA. Johnson, W. D. Clays of California. 9th Ann. Report 



California State Mineralogist, pp. 287-308. 1890. 

 Ries, H. The clay-working industry of the Pacific Coast 

 States. Mines and Minerals, vol. 20, pp. 487-488. 

 1900. 

 OLORADO. Lakes, A. Gypsum and clay in Colorado. Mines and 



Minerals, vol. 20. December, 1899. 

 Ries, H. The clays and clay-working industry of Colo- 

 rado. Trans. Am. Inst. Min. Engrs., vol. 27, pp. 336- 

 340. 1898. 

 FLORIDA. Memminger, C. J. Florida kaolin deposits. Eng. and 



Min. Journal, vol. 57, 436 pp. 1894. 

 Vaughan, T. W. Fullers' earth deposits of Florida and 

 Georgia. Bulletin 213, U. S. Geological Survey, pp. 

 392-399. 1903. 



* Bleininger, A. V. The manufacture of hydraulic cements. Bulletin 4, Ohio 

 Geol. Survey, pp. 102-108. 1904. Catlett, C. The hand-auger and hand-drill in 

 prospecting work. Trans. Amer. Inst. Min. Engrs., vol. 27, pp. 123-129. 1898. 

 Jones, C. C. A geologic and economic survey of the clay deposits of the lower 

 Hudson River Valley. Trans. Amer. Inst. Min. Engrs., vol. 29, pp. 40-83. 1900. 



