502 mckelvey. SEDIMENTARY MINERAL DEPOSITS [Ch. 27 



of hydraulics been applied to the search for and exploration of placers, 

 or our knowledge of physical and inorganic chemistry to the search 

 for chemical deposits? For how many minerals has the mode of oc- 

 currence of their known deposits — their areal variations in composition 

 and thickness as well as their relationships to the lithologic variations 

 of the enclosing beds, paleogeography, and tectonic history — been an- 

 alyzed systematically? Of equal importance to the acquisition of ad- 

 ditional facts are the systhesis and interpretation of data now avail- 

 able, not only in the literature of geology but of related sciences as well. 

 In conclusion, the size of the industry, the growing demand for new 

 discoveries, as well as for the application of techniques that will lead 

 to economies of mining, and the rapidly accumulating mass of unin- 

 terpreted facts about sedimentary rocks and processes combine to make 

 the field of sedimentary mineral deposits one of many opportunities for 

 geologists primarily interested in sediments. 



ACKNOWLEDGMENTS 



Whatever understanding I may have of the field of economic geology 

 of sedimentary mineral deposits and of the use currently made of geol- 

 ogy in the various phases of mineral exploitation, I owe as much to 

 discussion with friends and colleagues as to my own observations and 

 experience. I therefore wish to acknowledge with thanks the benefit 

 received from many talks on this general subject with D. F. Hewett, 

 M. R. Klepper, A. E. Weissenborn, E. P. Kaiser, E. C. Stephens, 

 O. N. Rove, and especially S. G. Lasky. 



REFERENCES 



The list of references given here is merely a sample of the literature on sedi- 

 mentary mineral deposits rather than a complete bibliography on the subject. 

 Treatises that discuss a wide variety of sedimentary deposits and contain ex- 

 tensive bibliographies are indicated by an asterisk. 



Allen, V. T. (1946). Sedimentary and volcanic processes in the formation of 

 high alumina clay: Econ. Geol., vol. 41, pp. 124-138. 



* American Institute of Mining and Metallurgical Engineers (1937). Industrial 



minerals and rocks: New York, 955 pages. 

 Ashley, G. H., et al. (1933). Classification and nomenclature of rock units: Bull. 

 Geol. Soc. Amer., vol. 44, pp. 423-459. 



* Bateman, A. M. (1942). Economic mineral deposits: John Wiley & Sons, New 

 York, 898 pages. 



Berkey, C. P. (1942). The geologist in public works: Bull. Geol. Soc. Amer., vol. 

 53, pp. 513-532. 



