INTRODUCTION 



"hypothetical," rathei' than "speculative." For some 

 commodities, this may simply reflect insufficient 

 knowledge of regional geology to identifiy other 

 promising areas, but for others it is an expression 

 of confidence that the favorable terranes have all 

 been identified. 



The entire field in the diagram of figure 1 repre- 

 sents our total primary resources (as distinct from 

 secondary resources, such as recycled scrap, vi^hich 

 are not considered in this volume) — identified re- 

 serves, plus potential resources, which consist of 

 conditional, hypothetical, and speculative resources. 

 Conversions of potential resources into reserves are 

 made by discovery, technologic advance, or changes 

 in economic conditions. The same processes may 

 lead to similar conversions from outside the field — 

 to make potential resources from materials at pres- 

 ent inconceivable as resources. 



A corollary of the emphasis of this volume on 

 geologic rather than economic factors is that our 

 classification is less concerned with the degrees of 

 feasibility of recovery defined by McKelvey. We 

 recognize that the concepts of paramarginal and 

 submarginal resources are valid, but because of the 

 broader objectives of this volume, nearly all our 

 authors found that a single degree of distinction 

 based on economic recoverability was difficult 

 enough to obtain for identified resources, let alone 

 for undiscovered resources, without the further 

 complication of another degree defined by a specific 

 price factor. Thus, nearly all the chapters of this 

 volume differentiate three major categories of re- 

 sources — identified, hypothetical, and speculative; 

 within the first category, most chapters differentiate 

 between recoverable identified resources (reserves), 

 and subeconomic identified resources (conditional 

 resources). In only a few chapters have the authors 

 attempted to extend the levels of economic recov- 

 erability into the hypothetical and speculative fields, 

 and where this has been done, it is generally in 

 terms of "recoverable" versus "subeconomic" — for 

 example, "subeconomic hypothetical resources." 



Special problems are posed in classifying the 

 resources found in sea-floor manganese nodules, in 

 metal-bearing muds of the Red Sea, and in the 

 recently discovered metal-bearing sedimentary rocks 

 of the Belt Supergroup in Idaho and Montana. Some 

 authors were reluctant to characterize the deposits 

 in these three environments as identified resources. 

 We see no question that they are identified, in that 

 they broadly fit the criteria of being known as to 

 existence and location ; but we well realize that they 

 are not fully evaluated. Our decision to classify 

 these resources as "identified," for consistency of 



treatment within this volume, may therefore be re- 

 garded as arbitrary and is in no way binding on 

 our authors or on our readers. We note, however, 

 that oflScials of two major U.S. mining companies 

 were recently reported to have said they "expect to 

 be selling metal made from the [sea-floor] nodules 

 by the end of the decade" (Faltermayer, 1972, p. 

 170). Such expectations, in our view, are not likely 

 to have been predicated on resources that are un- 

 discovered. 



PUBLIC AWARENESS, RESOURCE ESTIMATES, 

 AND GEOLOGIC AVAILABILITY 



Public awareness of our dependence on mineral 

 resources appears to be growing. With this grovrth 

 in awareness — and indeed responsible for some of 

 it — is a grovirth in the number of magazine and 

 newspaper articles, and even books, that attempt 

 to evaluate our supply of mineral resources and in 

 some cases to forecast economic or cultural trends 

 that are dependent on this supply. (See, for example, 

 Faltermayer, 1972; Meadows and others, 1972; U.S. 

 News and World Report, 1972.) The almost uni- 

 versal tendency of such articles is to discuss mineral 

 resources principally from the perspective of eco- 

 nomic availability under a given set of conditions, 

 thereby overlooking the vital fact that reserves are 

 but a part of resources. The results are, we feel, 

 disturbing. Evaluations predicated only on knowl- 

 edge (or estimates) of current reserves can easily 

 lead to forecasts of the death of the industrial so- 

 ciety in a short time. On the other hand, evalua- 

 tions based on another kind of assumption suggest 

 that a rise in prices will increase the reserves and 

 bring much more material to market economically 

 from lower and lower grade material in larger and 

 larger deposits. This reasoning too is fallacious be- 

 cause elements are available in the earth's crust in 

 very finite amounts. But in both instances, the 

 reasoning leads to serious misinterpretations be- 

 cause it does not give adequate consideration to the 

 single factor that ultimately determines all levels 

 and degrees of mineral potential: geologic avail- 

 ability. Geologic availability concerns the existence 

 and concentration of certain elements or combina- 

 tions of elements and is the most fundamental char- 

 acteristic of a mineral commodity that governs its 

 commercial use. 



Assessment of geologic availability of a com- 

 modity requires basic knowledge of the geology, 

 mineralogy, and geochemistry of that material, the 

 geologic environments in which it occurs, and its 

 concentration in those environments. The tech- 

 nology of exploration, mining, beneficiation, recov- 



