UNITED STATES MINERAL RESOURCES 



ery, and use is founded upon this information. 

 Studies of geologic availability are indispensable — 

 at all levels of commerce, industry, and govern- 

 ment — for any economic planning that considers 

 the available supply or use of primary mineral com- 

 modities and their byproducts. 



Generally, however, public concepts of the magni- 

 tude of mineral resources are based on evaluations 

 of economic rather than geologic availability, and 

 even these are subject to numerous problems. Sound, 

 accurate estimates of reserves for large regions are 

 highly difficult to compile, for many reasons. Re- 

 serve data from industrial deposits may not be 

 available because of the problems of competition 

 and taxes. Managements of many companies believe 

 that in the competitive atmosphere of business they 

 should not release information about their reserves. 

 Some States tax the reserves in the ground held by 

 mining companies, making it economically advan- 

 tageous, and in some cases necessary, to produce at 

 capacity for years from deposits that are continually 

 reported to be nearly exhausted. Definition of ton- 

 nages of mineral resources of sufficiently high grade 

 to be minable at current prices is difficult enough 

 without trying to distinguish grades minable at 1.5 

 or more times greater than the current price. Eco- 

 nomic evaluations of a specific mineral deposit have 

 become a complex task for a team of specialists, 

 including not only geologists but also mining engi- 

 neers, ore dressers, metallurgists, and economists. 

 So many complex factors govern price at any given 

 time that it would seem foolhardy to estimate re- 

 sources in each of the economic categories and 

 expect the results to be meaningful for very long. 



At some time, however, the pressures of both 

 economic and geologic factors will meet in crisis. 

 Economic factors may be altered rapidly. Changes 

 in demand and use alter patterns of production and 

 consumption; new deposits are sought elsewhere; 

 substitutes will be sought; and new technology will 

 be developed as the ingenuity of man is focused on 

 solving the problems. But there is no economic 

 availability if there is no geologic availability. Of 

 the two factors, geologic availability is the more 

 fundamental because without it economic availabil- 

 ity is not pertinent. Just as no biological miracle 

 can make it possible to extract blood from a turnip, 

 neither technological magic nor astronomic dollar 

 value can make it possible to extract gold or alumi- 

 num or borax or mica from rocks in which they are 

 not present. Geologic availability, therefore, is the 

 ultimate determinant of mineral potential, and it 

 is geologic availability that is stressed in the evalua- 

 tions of potential mineral resources in this volume. 



Few chapters in the volume attempt to distinguish 

 between tonnages now recoverable and those avail- 

 able only at subeconomic levels of the three 

 "certainty-of-existence" categories shown in figure 

 1, but virtually every chapter offers a quantitative 

 evaluation in numbers or words for the resources 

 in each of the three categories, and the use of the 

 threefold terminology has been applied as rigorously 

 and uniformly as practical in each chapter. 



GENERAL CONCaLUSIONS 



We realize that this book lacks a plot sufficient to 

 induce its readers into proceeding through it from 

 cover to cover. Therefore, we offer here some gen- 

 eral conclusions on several aspects of the Nation's 

 mineral-resource position, which have emerged 

 from our editorial overview of the chapters as 

 a whole. Of first importance is a summary answer 

 to the principal question to which the volume is 

 directed : Where do we stand with regard to re- 

 sources of each commodity? Other conclusions per- 

 tain to the increasing importance, as resources, of 

 large volumes of low-grade rocks, and attendant 

 environmental problems; the problem of enormous 

 quantities of potential mineral byproducts that are 

 now literally being wasted; the factor of energy in 

 the extraction of minerals ; and finally, the pressing 

 need for vigorous research along many lines. 



MINERAL POTENTIAL: WHERE DO WE STAND? 



Each chapter of the volume has its own calcula- 

 tion or other evaluation of resources governed by 

 those factors deemed by the authors to be important 

 to the respective commodity. There is no way to 

 make the data in each chapter absolutely compara- 

 ble. We would prefer that users of the volume read 

 the chapters of interest to them in order to obtain 

 the best possible understanding of the authors' pre- 

 sentation of resource data, and then formulate their 

 own conclusions. We have, however, compiled a 

 table that shows resource appraisals on a numerical 

 scale, for commodities of major importance, put 

 into perspective in terms of the minimum, antici- 

 pated cumulative demand ' for the period 1968-2000 

 as compiled by the U.S. Bureau of Mines (1970). 

 Once again we emphasize that the resources indi- 

 cated here are for the most part potential, and that 

 their eventual availability as reserves is entirely 

 dependent on continued geologic and technologic 

 research as well as economic factors. 



^ In using "demand" values for purposes of comparison we do not 

 represent them as being specific goals to be reached. This volume presents 

 no social or political judgments: its sole purpose is to make available 

 reliable geologic resource facts and assessments for public policy decision as 

 well as for use by the minerals industry. 



