Mineral Resource 

Perspectives 1975

GEOLOGICAL SURVEY PROFESSIONAL PAPER 940
Mineral Resource 

Perspectives 1975

GEOLOGICAL SURVEY PROFESSIONAL PAPER 940

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1976
UNITED STATES DEPARTMENT OF THE INTERIOR 

THOMAS S. KLEPPE, Secretary

GEOLOGICAL SURVEY

V. E. McKelvey, Director

First printing 1975 

Second printing 1976

Library of Congress Cataloging in Publication Data

United States. Geological Survey. Mineral resource perspectives 1975.

(Geological Survey professional paper; 940)

Bibliography: p.

Supt. of Doc. no.: I 19.16:940.

1. Mines and mineral resources-United States. I. Title. II. Series: United States. Geological Survey. Professional

paper; 940. 

TN23.U74 1975 553'.0973 75-619150

For sale by the Superintendent of Documents, U.S. Government Printing Office

Washington, D.C. 20402 

Stock Number 024-001-026734
PREFACE

The Mining and Minerals Policy Act of 1970, the Club of Rome's 

report "The Limits of Growth" (Meadows and others, 1972), and the 

U.S. National Commission on Materials Policy (1973) focused public attention on the Nation's dependence on mineral resources, and reports such 

as "United States Mineral Resources" (U.S. Geological Survey Professional Paper 820) and "Mineral Resources and the environment" (National 

Academy of Sciences, 1975) have broadened that concern. The problems 

of access to raw materials, though often minimized, are complex issues requiring factual data and careful analysis. This report, which supplements 

the annual report of the Secretary of the Interior under the Mining and 

Minerals Policy Act of 1970 (P.L. 91-631), provides current Geological 

Survey perspectives on the status of mineral resources research on other 

than energy materials, which will be considered elsewhere, and discusses 

progress toward a better understanding of the problems of minerals 

availability. The U.S. Bureau of Mines (1974b) has prepared a companion 

appraisal of mineral reserves, "Commodity Data Summaries 1974."

The task of evaluating mineral resources is a continuing one. Although mineral resources are not renewable that is, they cannot be regenerated or replaced at rates comparable with their extraction mineral 

reserves can be created from subeconomic resources or new discoveries, 

but the creation process is possible only through a concerted, well-planned, 

time-consuming effort by industry, academia, and Government. This report considers some of these problems and describes some .current research by the U.S. Geological Survey that is directed toward understanding the problems of access to mineral resources and the methods of their 

appraisal and exploration

Director

U.S. Geological Survey

111

CONTENTS

Preface __________________________ _________

Introduction ________________________________

What is our minerals problem? _________________

Classifying mineral resources __________________

Appraising mineral resources ________________

Methods ____________________________

Organizing data ____________________

The resource outlook ___________________________

Exploration for mineral resources _____________

Techniques for mineral exploration __________

Lead time _______________________________

Chances of success ________________________

Recent exploration activity ________________

Recent research on mining and extraction ____

Roles of industry and government in research ____

Mineral resources research programs in the

U.S. Geological Survey __________________

Regional appraisal ______________________ __

Areal geologic studies ______________________

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Mineral resources research programs Continued

Detailed studies in mining districts ___ _ 14

Geochemical exploration _______________ _ 15

Geophysical exploration __________ 15

Resource analysis ____________________ _ _ 16

Mineral resource studies by specialists _ __ 16

State reports requested by the U.S. Senate __ 16

Mineral appraisal of Federal lands _____ ___ 17

Conclusions: Some pressing problems _________ _ 20

Determining criticalness of mineral commodities 20

Depending on imported minerals ______ ____ 20

State of the mining industry ________________ 21

Reporting reserve data ____________________ 21

Recovering potential mineral byproducts _____ 22

Considering subsea mineral resources _______ 22

Staffing for mineral appraisal and exploration _ 22

Increasing public awareness ________________ 23

References cited ______________________________ 23

ILLUSTRATIONS

FIGURE 1. Classification of mineral resources ___________________________________________________

2. Organizations in the Geological Survey having program responsibilities for mineral resources 

research __________________________________________________________________

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12

TABLES

TABLE 1. United States' dependence on foreign sources for some of its minerals ___.

2. General outlook for domestic reserves and resources through 2000 A.D. ___.

3. Foreign exploration-development data reported in 1973 ____________________

4. Commodities in the mineral-resource-specialists program _______________ _

5. Federally owned land in 11 western States and Alaska as of June 30, 1971

6. Major landholding agencies in the Federal Government _______________ __

7. Three levels of resource appraisal used by the U.S. Geological Survey _____

8. Mineral resource appraisal of Federal lands completed to September 1974 _.

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MINERAL RESOURCE PERSPECTIVES 1975

INTRODUCTION

Energy materials are so much in the limelight today that little attention has been focused on the 

equally important but less obvious problem of availability of other miAerals for an expanding world industrial complex, or indeed for the increased production of energy. This report summarizes the status of 

mineral resources and mineral exploration in the 

United States and mineral resources research in the 

U.S. Geological Survey in 1974. It is intended for concerned citizens, scientists, planners, and policymakers, whether in industry, Government, or private 

life, who want to know more about current and potential mineral resource problems and what steps 

are being taken, or might be taken, to solve them. 

Bold-face type is used in the text to emphasize ideas 

which the authors consider to be especially significant. References are cited in parentheses by the author's name and the date of publication; full citations are given at the end of the report.

WHAT IS OUR MINERALS PROBLEM?

Our society is dependent on minerals, and without 

a steady supply of them it could not survive. Consider a few of the mineral products in a typical 

American home: 

Building materials: sand, gravel, stone, brick (clay),

cement, steel, aluminum, asphalt, glass. 

Plumbing and wiring materials: iron and steel,

copper, brass, lead, cement, asbestos, glass, tile,

plastic. 

Insulating materials: rock wool, fiberglass, gypsum

(plaster and wallboard). 

Paint and wallpaper: mineral pigments (such as iron,

zinc, and titanium) and fillers (such as talc and

asbestos). 

Plastic floor tiles, other plastics: mineral fillers and

pigments, petroleum products. 

Appliances: iron, copper, and many rare metals. 

Furniture: synthetic fibers made from minerals

(principally coal and petroleum products); steel

springs; wood finished with rotten-stone polish

and mineral varnish.

Clothing: natural fibers grown with mineral fertilizers; synthetic fibers made from minerals 

(principally coal and petroleum products). 

Food: grown with mineral fertilizers; processed and

packaged by machines made of metals. 

Drugs and cosmetics: mineral chemicals. 

Other items, such as windows, screens, light bulbs, 

porcelain fixtures, china, utensils, jewelry: all 

made from mineral products. 

In our homes, our offices, our, industries in almost every facet of our daily life we use minerals 

without knowing it, so hidden are many of their uses 

among the technical complexities of modern industrial processes and products.

The entire U.S. economy is based on minerals. In 

1972, the last full year prior to the pinch of the oil 

embargo, domestic raw materials valued at $32 billion were converted into energy and processed materials, the value of which exceeded $150 billion and 

formed the basis of the Gross National Product of 

$1.1 trillion (Mining and Minerals Policy, 1973).

Our problem is simply that the United States does 

not have an adequate known domestic supply of all 

the minerals needed to maintain our society for the 

foreseeable future. We never have had all we needed, 

but in the past we could easily obtain materials from 

abroad. Today we meet a smaller percentage of our 

needs from domestic supplies (table 1), and minerals 

from overseas are increasingly costly and, in some 

cases, of uncertain availability. Nationalization of 

mines in some countries discourages participation by 

American mining companies; cartel agreements 

among the major producing nations can suddenly 

and dramatically raise prices or even halt supply, as 

has happened recently with petroleum; and "developing" nations are now competing in the world market 

for the purchase of mineral raw materials.

The many facets of our problem become apparent 

when we consider the ways we might try to alleviate 

it:

By reducing the demand for scarce minerals, through 

substitution of others, reduction of waste, or 

elimination of some uses.
MINERAL RESOURCE PERSPECTIVES 1975

TABLE 1. United States' dependence on foreign sources for 

some of its minerals

[Mining and Minerals Policy, 1973]

a. Less than half imported from foreign sources: 

Copper Tellurium 

Iron Stone 

Titanium (ilmenite) Cement 

Lead Salt 

Silicon Gypsum 

Magnesium Barite 

Molybdenum Rare earths 

Vanadium Pumice 

Antimony

b. One-half to three-fourths imported from foreign sources: 

Zinc Nickel 

Gold Cadmium 

Silver Selenium 

Tungsten Potassium

c. More than three-fourths imported from foreign sources: 

Alu/ninum Tantalum

* Manganese Bismuth 

Platinum Fluorine 

Tin * Strontium

*Cobalt Asbestos

*Chromium "Sheet mica

* Titanium (rutile) Mercury

* Niobium

* Commodities more than 90 percent imported.

By supplementing the raw mineral supply, through 

recovery and recycling of scrap and used materials. Recycling of scrap (from junk) already 

provides significant amounts of some metals 

over half of our annual needs for antimony and 

one-quarter to one-third of that for iron, lead, 

nickel, mercury, silver, and gold (Mining and 

Minerals Policy, 1973, p. 20). Research on recycling of domestic and industrial waste is developing new processes for use by industry. 

By increasing our domestic supply, through discovery of new mineral deposits and through development of technology for the feasible recovery of low-grade deposits. 

From the perspective of the 1970's, increasing our 

domestic supply of minerals seems imperative. A 

widespread misconception, however, allows that this 

is simply a matter of economics and technology 

that the Earth's crust is; an infinite storehouse that 

can readily be tapped for new supplies of all kinds of 

mineral raw materials by either raising the price or 

developing new technology (which in turn may raise 

the price). The economic and technologic factors governing mineral supply cannot be ignored, but neither 

can another more fundamental factor: geologic 

availability. A mineral resource is a concentration of 

elements or compounds in certain rocks, or in certain geologic environments, in a form that can yield 

a useable mineral commodity, but such concentrations are geologic rarities, and even low-grade deposits are anomalous concentrations. If a mineral is

not geologically available, favorable economics and 

technology are not pertinent.

Nor is "raising the price" as simple as it sounds. 

Raising the price may actually reduce the supply of 

a mineral commodity brought from existing facilities to market per unit of time, because the higher 

price enables the Company to mine a lower grade 

ore, thereby reducing the amount of concentrate derived from the same mill per unit of time. The mining and milling capacity of a property is almost never 

increased to accommodate what are believed to be 

short-term price fluctuations.

The use of increasingly lower grades of ore poses 

two other problems. First, more energy must be 

spent, both to dig the ore from the ground and to extract the mineral from it. Second, the environmental 

Impact is greater, not only as a result of mining 

larger volumes of rock and discarding larger volumes 

of waste, but also because of the increased energy 

and water requirements.

Realistic appraisals of the quantities of mineral 

resources remaining to be developed and yet to be 

discovered are a matter of concern for many policymakers in both industry and Government, but mineral resources cannot be inventoried like cans on a 

shelf. Reserves, or mineral resources 'that have been 

found, sampled, and measured and that can be legally 

and profitably mined under present conditions, can 

be inventoried (although on a national scale the inventory is only accurate to the extent that mining 

companies are willing to release data). But in addition to these reserves, there are: known, low-grade 

deposits not profitable to mine now; new deposits of, 

reserve quality that can be logically inferred to exist 

but are as yet undiscovered; and even new types of 

deposits not yet recognized. These are all mineral 

resources, and appraising them accurately is perhaps as difficult as appraising the 1985 wheat crop. 

Resources can be estimated only by successive approximations, subject to constant change as known 

deposits are worked out, as new deposits are found, 

and as new techniques of exploration, mining, and 

processing are developed, literally creating reserves 

from material that was previously unuseable. And so 

an important facet of the minerals problem is the 

need to improve methods for appraising resources 

and to have the successive estimates come closer and 

closer to being coincident with the amount of material actually occurring.

CLASSIFYING MINERAL RESOURCES

Through the years geologists, mining engineers, 

and economists have used many terms to describe
CLASSIFYING MINERAL RESOURCES

and classify mineral reserves and resources. Some of 

these terms have gained wide use and acceptance, 

although their use by different authors commonly 

has been marked by a vagueness that makes precise 

comparison of data difficult. More uniform use of 

reserve and resource terminology is critical to better 

communication on this vital subject.

Modern attempts to establish a standard terminology of mineral resources began during World 

War II when the U.S. Bureau of Mines and the U.S. 

Geological Survey (1947) were assessing the Nation's mineral position. That terminology was reviewed and revised later by a committee of the Society of Economic Geologists (Blondel and Lasky, 

1956). More recently McKelvey (1972) and Brobst 

and Pratt (1973) have discussed concepts of mineral 

resources and their terminology and emphasized the 

need for understanding the broader implications of 

the difference between reserves and several categories of mineral resources.

In anticipation of increased activity in the assessment of mineral resources during the coming years, 

the staffs of the U.S. Bureau of Mines and the U.S. 

Geological Survey have collaborated in a joint state^ 

ment on the classification of mineral resources. The 

classification (summarized here) is intended to be 

useful for all mineral commodities, including the 

energy materials, although supplementary essays 

dealing with classification problems peculiar to certain commodities may be required.

The distinction between resources and reserves is 

based on current geologic and economic factors. A 

resource is a concentration of naturally occurring 

solid, liquid, or gaseous materials in or on the Earth's 

crust in such form that economic extraction of a 

commodity is* currently or potentially feasible. A 

reserve is that portion of the identified resource 

from which a useable mineral or energy commodity 

can be economically and legally extracted at the 

time of determination. The term ore is used for reserves of some minerals. Resources thus include, in 

addition to reserves, other mineral deposits that may 

eventually become available known deposits that 

cannot be profitably mined at present, because of economics, technology, or legal restraints, and also unknown deposits, rich and lean, that may be inferred 

to exist on the basis of geological evaluation but 

have not yet been discovered. An analogy from the 

field of personal finance may help to clarify the distinction: reserves are represented by the funds in 

one's bank account and by other liquid assets; resources include, in addition, all other assets and all 

anticipated future income, from whatever source.

Public attention usually is focused on reserves of 

mineral or energy materials. Long-term public and 

commercial planning, however, must be based on the

probability of geologic discovery of new deposits and 

technologic development of economic extraction processes for currently unworkable deposits. Thus, all 

components of total resources must be continuously 

reassessed in the light of new geologic knowledge, 

of progress in technology, and of shifts in economic 

and political conditions.

Another requirement of long-term planning is the 

weighing of multicommodity or total resource availability against a particular need. The general classification system must therefore be uniformly applicable to all commodities so that data for alternate 

or substitute commodities can be compared.

To serve these planning purposes, total resources 

are classified in terms of both economic feasibility 

and the degree of geologic assurance of their occurrence (fig. 1).

As shown in figure 1, total resources are divided 

into two major fields, identified and undiscovered 

resources; they in turn are subdivided. The resource 

terms that will be most useful to readers are: 

Identified resources: Specific bodies of mineralbearing material, the location, quality, and 

quantity of which are known from geologic 

evidence and, if they are in the demonstrated 

category, are supported by engineering measurements.

Reserves (already defined). 

Identified subeconomic resources: Resources 

that may become reserves as a result of 

changes in economic, technologic, and legal 

conditions.

Undiscovered resources: Bodies of mineral-bearing 

material surmised to exist on the basis of 

broad geologic knowledge and theory. Exploration that confirms their existence and reveals quantity and quality will permit their 

reclassification as reserves or as identified 

subeconomic resources.

Hypothetical resources: Undiscovered resources 

that may reasonably be expected to exist 

in a known mining district under known 

geologic conditions.

Speculative resources: Undiscovered resources 

that may exist either as known types of 

deposits in a favorable geologic setting 

where no discoveries have been made or as 

unknown types of deposits that remain to be 

recognized.
MINERAL RESOURCE PERSPECTIVES 1975

TOTAL RESOURCES

IDENTIFIED

Demonstrated

RESERVES

UNDISCOVERED

HYPOTHETICAL 

(In Known 

districts)

SPECULATIVE

(In undiscovered

districts)

RESOURCES

+- f +

Increasing degree of 

geologic assurance

FIGURE 1. Classification of mineral resources.

Measured, indicated, and inferred are terms applicable to both reserves and identified subeconomic 

resources.

Measured. Identified resources for which tonnage is computed from dimensions revealed in outcrops, trenches, workings, and drill holes and for 

which grade is computed from the results of detailed sampling. The sites for inspection, sampling, 

and measurement are spaced so closely and the geologic character is so well defined that size, shape, 

and mineral content are well established. The computed tonnage and grade are judged to be accurate 

within limits which are stated, and no such limit is 

judged to be different from the computed tonnage 

or grade by more than 20 percent.

Indicated. Identified resources for which tonnage and grade are computed partly from specific 

measurements, samples, or production data and partly from projection for a reasonable distance on the 

basis of geologic evidence. The sites available for inspection, measurement, and sampling are too widely or otherwise inappropriately spaced to permit the 

mineral bodies to be outlined completely or the grade 

to be established throughout.

Inferred. Identified resources for which quantitative estimates are based largely on broad knowledge of the geologic character of the deposit and for 

which there are few, if any, samples or measurements. Continuity or repetition is assumed on the 

basis of geologic evidence, which may include comparison with deposits of similar type. Bodies that are 

completely concealed may be included if there is 

specific geologic evidence of their presence. Estimates of inferred reserves or resources should include a statement of the specific limits within which 

the inferred material may lie.

The terms proved, probable, and possible (used by 

industry for economic evaluations of ore in specific 

deposits or districts) commonly have been used 

loosely and interchangeably with the terms measured, indicated, or inferred (used by the Department of the Interior mainly for regional or national 

estimates). "Proved" and "measured" are essentially 

synonymous. "Probable" and "possible," however, 

are not synonymous with "indicated" and "inferred." 

"Probable" and "possible" describe estimates of partly sampled deposits in some definitions, for example, "probable" is used to describe deposits sampled on two or three sides, and "possible" for deposits sampled only on one side; in the Bureau/ 

Survey definitions, both would be described by the 

term "indicated."

Long-range estimates of resources are little affected by increases of reserves brought about by new 

discoveries or new technologic or economic developments. What such developments do, in effect, is simply add tons or ounces to the reserve category by 

taking them away from one of the resource categories shown in figure 1. Such developments are the 

life blood of the mineral industry because they replenish the dwindling reserves. But they do not alter 

the total resource picture substantially. A significant increase in the total resources is brought about 

only by a major scientific or technologic breakthrough.

Consider, for example, recent estimates of gold resources. In 1967, when the price of gold was $35 per 

ounce, the U.S. Bureau of Mines estimated 244 million ounces of gold as identified subeconomic resources, potentially recoverable at prices as high as 

$145 per ounce. With the price in the $160-190 range, 

as it was late in 1974, those formerly subeconomic 

resources can be regarded as reserves but the total 

resources remain unchanged. On the other hand, gold 

in seawater is not now considered a resource because 

of its low concentration only as much as 0.05 parts 

per billion, or about 1 ounce of gold per million cubic 

metres of seawater. Discovery of a method for recovering this gold economically on a commercial scale 

would add spectacularly to the world's total resources 

of gold, on the order of 1,000 ounces per cubic kilometre of seawater. In the 1960's, recognition of a new 

type of resource (the so-called disseminated gold, or 

Carlin type) was a scientific milestone that added 

millions of ounces of gold to the categories of identified, hypothetical, and speculative resources.
CLASSIFYING MINERAL RESOURCES

APPRAISING MINERAL RESOURCES

Mineral reserves and resources are dynamic quantities and must be constantly appraised as known 

deposits are worked out, new deposits are found, new 

extractive technologies and uses are developed, and 

new geologic knowledge indicates new areas and environments favorable for exploration. A final, onceand-for-all "inventory" of any mineral resource is 

nonsense. Indeed, appraising the national resources 

of any mineral commodity is at this time an emerging 

science, and a universally accepted appraisal method 

has yet to be found.

METHODS

Resource appraisals made in the past have differed 

greatly because they were made by different methods 

to fill different needs. Many are of limited use as 

appraisals of total resource potential because of limitations imposed by the purpose for which they were 

made. In general, two types of approaches have been 

taken. One utilizes extrapolations based on production and economic information; the other utilizes 

extrapolations based on information about geologic 

occurrence. More recently, geomathematical techniques have been applied to help quantify both types.

Approaches that extrapolate from production and 

economic data consider such variables as improvements in discovery and recovery techniques and 

changes in the economics of exploration, production, 

and marketing (for example, Hubbert, 1962, 1967, 

1969; Moore, 1966, 1970). Some incorporate the declining efficiency in exploration, the growth of reserves by additions, and (or) the effects of price 

changes on resource potential (Arps and others, 

1970; Brinck, 1972; Bieniewski and others, 1971). 

Such approaches tend to allow neither for possible 

breakthroughs that might make subeconomic occurrences recoverable, nor for possible new discoveries 

in unexplored areas, and so they have limitations for 

appraising total resource potential.

Approaches that emphasize geologic occurrence 

extrapolate data about mineral deposits from explored to unexplored areas. Such geologic evaluation 

has been used to estimate the number of undiscovered porphyry copper deposits in the Southwestern 

United States, British Columbia, Chile, and Peru 

(Lowell, 1970) and to estimate the quantity of several mineral commodities remaining to be discovered 

in the area north of 60° latitude in Canada (Derry, 

1973). This concept of basing mineral resource appraisals on geological extrapolations has been extended by the use of such geomathematical techniques as statistical treatment of opinion polls

(Harris and others, 1970) and construction of decision models (Allais, 1957, based on Nolan, 1950; 

Slichter and others, 1962).

Ideally, resource appraisals should be made by 

dividing the total unmined resources of each commodity into specific geologic, technologic, and economic subsets, each with its own estimate and each 

explicitly defined so that its validity can be tested. 

The procedure by which these estimates are made 

should be flexible so that new information can be 

readily incorporated. The precision of an estimate 

should be stated as explicitly as possible and expressed within prescribed limits of confidence; in 

practice, however, such confidence intervals are difficult to construct because the assumptions used in 

making geologic extrapolations about occurrences of 

mineral commodities are likely to vary, and variability of this sort is not easily reduced to numbers. The 

assumptions used to construct an estimate should 

therefore also be stated explicitly. Bias should be 

avoided; the analyst should not alter an estimate in 

order to be conservative or optimistic.

The most recent comprehensive mineral resource 

appraisal by commodity for the United States (and, 

for some commodities, for the world) was published 

by the U.S. Geological Survey (Brobst and Pratt, 

1973). The methods used to appraise 65 commodities 

are diverse, but most of them are variants of geologic extrapolation. The appraisals span a broad 

range, from qualitative to quantitative, and none of 

the authors would claim that his evaluation is a 

definitive resource appraisal.

In "Project Appalachia" the Geological Survey of 

Canada currently is combining expertise in regional 

geology, mineral-deposit geology, and mathematical 

processing to provide three approaches to evaluation (1) a traditional metallogenic (geologic extrapolation) appraisal, (2) a metallogenic-based geomathematical evaluation, and (3) an opinion-poll 

appraisal. The Canadian Appalachian region was selected for this pilot study because its size is convenient, its geology is relatively well known, and it 

contains a variety of mineral deposits. Results of the 

three appraisals will be compared and will be followed up with an opportunity for a second round of 

opinions based on comments from the first.

On July 1, 1974, the U.S. Geological Survey began 

a new multidisciplinary program of field and laboratory studies designed to assess the metal and selected nonmetal resources of Alaska. Because mineral 

appraisals of such large, remote, and little-known 

regions as Alaska are still largely experimental, a 

two-year program called the Prototype Alaskan Min-
MINERAL RESOURCE PERSPECTIVES 1975

era! Resource Assessment Program (PAMRAP) will 

develop guidelines, techniques, and products as a 

model for a future statewide mineral assessment 

program. For each l:250,000-scale (l°-by-3°) quadrangle studied, geologic, geochemical, and geophysical maps, and computer-enhanced data from satellites (multispectral ERTS imagery) will be interpreted to produce a mineral-potential map. This will 

be accompanied by a tabular summary of known 

mines, prospects, and occurrences, and by resourceassessment diagrams showing estimates of identified, hypothetical, and speculative resources.

ORGANIZING DATA

Increasing attention to both geologic and economic evaluation of mineral resources will inevitably 

generate great masses of numerical data and information which will require skillful organization if it 

is to be effectively utilized. Because the subject of 

mineral resources is broad in scope and complexity, 

involving principally the fields of geology, mining 

engineering, and economics but also many other 

closely related, highly technical subjects, and because of the great variety of basic raw materials 

and the wide range of needs and use patterns, data 

on mineral resources are difficult to organize, gain 

access to, and use effectively. Computerized processing now offers the best available means of improving 

the usefulness of data. The computer can separate 

a whole file into its parts, perform operations on 

parts, and then reorganize the file. Moreover, a computerized file can be constantly updated, thus eliminating a major problem with the old manual systems. A computer can accomplish in seconds many 

operations of data which would never even be attempted by manual methods; thus all important 

relationships of available data can be determined.

Computerized files of resource data now in use 

within the U.S. Geological Survey and U.S. Bureau 

of Mines include:

1. CRIB Computerized Resources Information 

Bank (for mineral resource data), U.S. Geological Survey.

2. MAS Minerals Availability System, U.S. Bureau of Mines.

3. Oil and gas file of the Office of Oil and Gas and 

U.S. Geological Survey.

4. Production/Consumption surveys of the U.S. 

Bureau of Mines.

THE RESOURCE OUTLOOK

To try to summarize the "status of resources" in 

a simple numerical table, showing tons of this or 

that commodity, would be like trying to sketch a

sunset in black and white. Describing the full spectrum of resources, like painting a sunset, requires 

the skillful blending of a full palette of hues the 

geologic, technologic, economic, and legal factors 

that make the appraisal of resources so complex. To 

disregard these factors and to tabulate resource 

estimates as raw numbers removed from their context inevitably lead to misinterpretation.

The essentials of the resource situation can be 

expressed by grouping the important commodities 

according to the general domestic outlook for reserves and resources for the remainder of the twentieth century. These groupings are listed in table 2. 

An indication of our dependence on foreign sources 

for some commodities was given in table 1.

TABLE 2. General outlook for domestic reserves and resources 

through 2000 A.D.

[Within each group, commoditi

Group 1: RESERVES in quantities adequate to fulfill projected needs well beyond 25 years.

Coal Phosphorus 

Construction stone Silicon 

Sand and gravel Molybdenum 

Nitrogen Gypsum 

Chlorine Bromine 

Hydrogen Boron 

Titanium (except Argon

rutile) Diatomite 

Soda *Barite 

Calcium Lightweight aggregates 

Clays Helium 

Potash Peat 

Magnesium *Rare earths 

Oxygen *Lithium

Group 2: IDENTIFIED SUBECONOMIC RESOURCES in 

quantities adequate to fulfill projected needs beyond 25 

years and in quantities significantly or slightly greater 

than estimated UNDISCOVERED RESOURCES. 

Aluminum Vanadium

* Nickel * Zircon 

Uranium Thorium 

Manganese

Group 3: Estimated UNDISCOVERED (hypothetical and 

speculative) RESOURCES in quantities adequate to fulfill projected needs beyond 25 years and in quantities significantly greater than IDENTIFIED SUBECONOMIC 

RESOURCES; research efforts for these commodities 

should concentrate on geologic theory and exploration 

methods aimed at discovering new resources. 

Iron Platinum

* Copper Tungsten

*Zinc *Beryllium 

Gold *Cobalt

*Lead * Cadmium 

Sulfur * Bismuth

* Silver Selenium

*Fluorine *Niobium

Group 4: IDENTIFIED-SUBECONOMIC and UNDISCOVERED RESOURCES together in quantities probably not 

adequate to fulfill projected needs beyond the end of the 

century; research on possible new exploration targets, 

new types of deposits, and substitutes is necessary to 

relieve ultimate dependence on imports. 

Tin * Antimony 

Asbestos *Mercury 

Chromium ^Tantalum
THE RESOURCE OUTLOOK

Known U.S. reserves of many minerals represent 

only a few years' supply. The outlook for resources 

is somewhat better, but to bring them into the category of available reserves will require enormous and 

costly efforts of exploration and research. Details 

on the technologic and geologic problems of utilizing 

resources of specific commodities are in U.S. Bureau 

of Mines (1970, Bulletin 650); Brobst and Pratt 

(1973, U.S. Geological Survey Professional Paper 

820); and a shorter report by Pratt and Brobst 

(1974) that summarizes the principal findings of 

Professional Paper 820 with regard to the resources 

of 27 major mineral commodities.

EXPLORATION FOR MINERAL RESOURCES

According to a U.S. Geological Survey compilation 

from the literature, the world's mineral-reserve 

wealth was increased in 1973 by nearly 100 million 

tons of copper; 40 million tons of nickel; several billion tons of iron ore and bauxite; about 38 million 

tons of zinc; and about 21 million tons of lead. These 

developments and increased productive capacities are 

the result of many years of concerted effort by governments and industry.

To maintain the forward thrust of such activities, 

extensive research and increased exploration activities for new deposits in unexplored but geologically 

favorable areas are essential. New or improved exploration techniques and geological concepts must be 

devised. The technology to develop mineral deposits 

and to increase the recovery of metal from low-g^ade 

ores must be improved. New policies and-guidelines 

must be established so that long-range programs of 

research, discovery, and development may be conducted and investment capital attracted-to support 

the mineral industry. Closer cooperation between 

government agencies, universities, and private industry is essential for a better understanding of geological and technical problems.

TECHNIQUES FOR MINERAL EXPLORATION

Most of the mineral deposits discovered before the 

twentieth century were found because they were 

exposed at the Earth's surface and contained high 

concentrations of the minerals sought. Commonly 

these minerals were fairly obvious; they occurred 

as brightly colored stains or as shiny grains on outcrops or in stream sediments.

In many parts of the world today, most of these 

obvious mineral deposits have already been discovered. The emphasis in the search for new resources 

is therefore on finding low-grade deposits that would 

not have been profitable to mine in the past, deposits

that are poorly exposed or not exposed at all, and 

deposits of previously unknown types that exhibit 

no obvious visual surface expression.

Mineral exploration today is a highly sophisticated, expensive and involved science that includes 

regional appraisal, reconnaissance geological studies, 

and physical exploration. The role of the traditional 

mineral prospector who searched for and sampled 

outcrops continues to decline in importance as the 

most obviously mineralized areas become thoroughly 

explored. The equipment used today is more sophisticated and the techniques are costlier than the early 

prospector could have imagined. At the same time, 

domestic lands available for prospecting are becoming more restricted with the establishment of primitive and wilderness areas, parks, monuments, and 

wildlife refuges. In some areas, urban expansion and 

environmental-protection measures limit access and 

restrict operations.

Modern exploration activities include geologic, 

geochemical, and geophysical investigations; threedimensional sampling by core drilling or other 

methods; laboratory analyses including ore treatment, concentration, and recovery tests; economic 

appraisal; and evaluation of transportation, water, 

and energy requirements. Favorable results must be 

obtained from these studies before a property or a 

mineral deposit can be considered for development.

Geology is the principal discipline used in mineral 

exploration; a thorough understanding of the physical and chemical characteristics of mineral deposits 

is essential. In regional geologic appraisals an exploration geologist may use such concepts as global 

tectonics, metallogeilic provinces; metallotects (geologic features believed to have influenced the localization or concentration of elements in the Earth's 

crust); the relationships between geochemical abundance and mineral resources; the relationship between crustal abundance and the size of resources; 

and multivariate geostatistical analysis.

Geochemical exploration uses the systematic 

measurement of one or more chemical properties of 

a naturally occurring material to discover and delineate abnormal chemical patterns that may be related 

to potentially economic mineral deposits. The chemical property most commonly measured is the concentration of an element, or of a group of elements, 

in rock, soil, or streambed sediments, in vegetation, 

in well, stream, lake, or ocean water, in glacial debris, 

or in airborne volatile materials.

Exploration geophysics applies the principles of 

physics to the search for mineral deposits that occur 

in the Earth's subsurface. Most geophysical work is
8 MINERAL RESOURCE PERSPECTIVES 1975

done with sophisticated electronic equipment that 

can detect subtle contrasts in such physical properties as specific gravity, electrical conductivity, heat 

conductivity, seismic velocity, and magnetic susceptibility. The common techniques used, either singly or 

in combination, are gravity, magnetic, electrical, 

electromagnetic, seismic, and radioactivity methods. 

Measurements may be made from aircraft, at the 

Earth's surface, or in boreholes.

In recent years, a variety of "telegeologic" or "remote sensing" techniques measurements of various 

geologic or related properties from aircraft or satellites have provided insights into complex structures 

of some regions where much of the bedrock is concealed. Side-looking radar imagery or photography 

has provided useful base maps in areas where conventional photographic methods had failed because 

of adverse weather and atmospheric conditions. 

LANDSAT, formerly Earth Resources Technology 

Satellite, imagery of many areas provides information on potential mineral and mineral-fuel deposits 

and is proving to be valuable for a better understanding of ground-water conditions and water-management problems. Preliminary results in Alaska and 

elsewhere suggest that LANDSAT data may have 

significant value in monitoring environmental effects 

of mineral and fuel production activities.

Modern laboratory techniques are applied in exploration projects. Electron-probe X-ray microanalysis, new rapid chemical analysis, visual colorcomparison techniques, and neutron-activation analysis have been found particularly useful.

In addition to exploration on land and in the air, 

government and industry are engaged in designing 

and testing exploration and mining equipment for 

undersea exploration operations.

LEAD TIME

Following a preliminary regional appraisal and 

assuming that jurisdictional and land acquisition 

problems in selected areas are resolved, reconnaissance geological mapping and studies, detailed geological mapping, geochemical and geophysical investigations, physical exploration, bulk sampling, 

ore testing, reserve calculations, and economic evaluations commonly require many years of concerted 

effort and large amounts of capital investment before 

a mineral deposit may be considered for development. 

Lead time of 20 years or more may be necessary 

from the beginning of the exploration project to 

the delineation of an economic mineral deposit. 

Mine development and plant construction activities 

require several additional years and more capital

expenditure before a mineral commodity is produced and marketed. For example: 

In 1929, officals of the Copper Range Company recognized that a large deposit of copper ore existed 

in the White Pine areas of the Michigan Upper 

Peninsula, but it was not until 1955 that production started at the mine following completion 

of exploration and development projects at a 

cost of 61.7 million dollars.

For a period of 10 years, the Bear Creek Mining Company has been exploring a copper-silver prospect 

in the Spar Lake district of western Sander 

County, Montana. The American Smelting and 

Refining Company, which has entered into an 

agreement to develop the property, indicates 

that the feasibility study and mine development 

will require 13 to 18 years.

The Amax's Henderson molybdenum mine in Colorado, which is expected to start production in 

1975, required 8 years of development at an estimated cost of about 250 million dollars. 

At the Granduc mine, British Columbia, geological 

investigations, surface exploration drilling, and 

ore testing required nearly 12 years, and 5 additional years were needed for development work 

before production began in 1970. Total cost of 

these activities was nearly 115 million dollars. 

The Michiquillay copper ore. deposit in Peru was 

investigated initially in the 1950's, but production is not scheduled to start before 1980 or 

later.

None of these examples takes into account the 

time and expenses involved in the initial stages of 

regional appraisal. Because the mineral industry is 

so competitive, little information, published or unpublished, is made available in the early stages of 

regional appraisal and land-acquisition activities.

Factors such as location, size of area under study, 

availability of base and geological maps, aerial photographs, and geologic reports all affect the time 

needed and expenses involved at this early stage. 

In the period 1955-69, nearly one billion dollars was 

spent in exploration ventures in the Western United 

States. In 1972, more than 32 million dollars was 

spent in worldwide geophysical and geochemical 

studies, 4.3 million of which was spent in the United 

States.

CHANCES OF SUCCESS

An exploration project that leads to discovery,

development, and production is exceptional, and the

odds against making a significant discovery are high:

Under the Strategic Mineral Development program

in the period 1939-1949, about 10,000 prospects
EXPLORATION FOR MINERAL RESOURCES 9

were examined; of these 1,342 deposits were 

investigated in detail, but only 1,053 contained 

enough tonnage to be of interest. The outstanding development resulting from this program 

was the San Manuel copper mine in Arizona. 

The Defense Minerals Exploration unit (established 

by the DME Act) in the period 1951-1958 received 3,888 applications for Federal financial 

assistance to explore deposits of strategic and 

critical minerals. Of 1,159 contracts granted, 

399 resulted in the certification of discovery of 

some valuable minerals, and by 1959, 45 of the 

deposits were in production. The outstanding 

discoveries of this program included zinc ore 

deposits in Tennessee and lead deposits in the 

Viburnum district of Missouri.

RECENT EXPLORATION ACTIVITY

In recent years, worldwide exploration for nonfuel 

minerals has focused principally on copper, iron, 

bauxite, lead-zinc, nickel-copper, uranium, and fertilizer materials. Improved prices for gold and silver 

have stimulated search for precious metals. Offshore 

exploration is receiving more attention than heretofore.

Exploration activities are gaining momentum in 

the United States and in Brazil, 'Europe, South 

Africa, and the Southwest Pacific. Governmental 

constraints, however, and new investment and mining policies in Australia, British Columbia, Zambia, 

and Peru have discouraged exploration efforts in 

these areas.

Major exploration targets in the United States 

have been disseminated copper, gold, molybdenum, 

and uranium deposits, stratiform copper deposits, 

stratabound lead-zinc deposits, and mineral deposits 

in volcanic sedimentary sequences. The Precambrian 

Belt series (extending from Libby, Montana, to the 

Coeur d'Alene district of Idaho); certain districts in 

Wisconsin, Minnesota, and Tennessee; and some unexplored areas in Alaska have received more than 

usual attention. Exploration for copper porphyries, 

massive sulfides, and Mississippi Valley-type leadzinc deposits has continued in the Appalachian region. Interim results were reported on nickel-copper 

investigations in Minnesota where, within a large, 

low-grade mineralized area, some deposits are estimated to contain as much as 100 million tons of rock 

that is 0.8 percent combined copper-nickel. Other 

projects include exploration for zinc in central Tennessee; for molybdenum in Idaho and Colorado; for 

copper in Arizona, Montana, Utah, Nevada, Wyoming, and Washington; and for platinum in Montana.

Also in the United States, known base-metal ore 

bodies have been extended in the Coeur d'Alene area 

of Idaho, and large deposits have been developed at 

Buick, Mo., and Gainsboro, Tenn. Preliminary reports 

have been made of exploration, development, and 

reactivation of old precious metal mining districts 

in Nome, Alaska; Silverton and Cripple Creek, Colo.; 

Pinson, Nev.; Mocassin, Mont.; and Wenatchee, 

Wash. The Homestake Mining Company announced 

the expenditure of several million dollars at the 

Homestake gold mine, South Dakota, to develop 

about 13 million tons of ore hitherto considered subeconomic. Exploration for uranium deposits has continued principally in Wyoming, Utah, Colorado, and 

New Mexico. No significant discoveries have been 

announced, but some earlier discoveries are being 

developed.

Recent developments in Canada include lead-zincsilver deposits of the Strathcona mine in Baffin 

Islands, the Arvik mine in the Northwest Territories, 

and the extension of the Kidd Creek ore body, Ontario, Bathhurst district in New Brunswick and the 

Gays River area, Nova Scotia. Significant discoveries 

of copper were also reported in Sonora, Mexico.

Elsewhere in the world, exploration for aluminum 

ore (bauxite) is focused principally on Australia, 

Brazil, and West Africa; for iron, on Brazil, West 

Africa, Australia, North Korea, and India; for copper, on Panama, Peru, Chile, Argentina, Australia, 

Philippines, Indonesia, Pakistan, Iran, India, Yugoslavia, Sweden, U.S.S.R., Zaire, Zambia, Ethiopia, 

and Southwest Africa; and for nickel, on Africa, 

Australia, Indonesia, Philippines, India, and Brazil.

Trade journals regularly report new developments 

in the mineral industry. A comprehensive survey, for 

example, of international mining activities was published in the British journal Mining Magazine 

(1974).

Results of exploration efforts outside the United 

States, measured by additions to the world's reserves of the major metals, are summarized by continent in table 3. Impressive as these data are for 

tons of reserves reported, explored and (or) developed, and expenditures noted, the reader must 

keep in mind at least three facts:

1. Lead time to reach production levels may be 15 

or more years for many of the individual 

Projects.

2. The products from the foreign developments will 

for the most part be available to the world 

market and are not automatically destined for 

United States consumption.

3. Expenditures yet to be made may be many times 

those already reported.
10 MINERAL RESOURCE PERSPECTIVES 1975

TABLE 3. Foreign exploration-development data reported in 1973

Location and

mineral

Bauxite ___ _ _ _ _ .

Copper __ __ __ _ ___.

Iron ore _ _

Gold 2 _ __ _

Total _ _.

Lead-zinc _ _ _ _ .

Nickel _ __ .

Total _ _ .

Copper _ _ .

Lead -zinc __ _ _ _.

Nickel

Gold 3 ___ __ __ ____.

Total _ __ _ .

Copper _ __ __ _

Iron ore _ _ ____.

Total

Bauxite

Copper _ _ _

Nickel __

Total -_ ______

Bauxite ___

Iron ore ___ __ _ _ _ _

Nickel __ _____ _______

Gold 5 __ _ _ __ __

Total _

Bauxite _ _ _ _

Copper ___ _ _ __

Nickel _ _ ___

Total __ __

Indicated reserve

of tons )

1,490

250

8,880

g

. _ 225

130

95

. __ 970

. __ 2,420

95

35

3,735

230

1,900

245

. _ 230

6

._ _ 1,600

_ _ 3,300

_ __ 255

540

60

_ __ 775

_ _ 800

150

__ 820

_ __ 4,000

8,690

_ _ 24,475

__ _ 190

__ 50

_ __ 80

2,470

5

1,590

Grade (percent)

From

Africa

42

0.8

35

8

0.7

0.5

Asia

45

0.9

17 7

0.8

Australia

45

0.7

60

0

1.3

0.2

Canada

0.4

23

7

0.33

Europe

54

0.7

50

9

1.2

Latin America

High grade

0.4

46

1.0

0.15 __ _ -__

Oceania

50 _____________

0.45

5.2 ___ ___ _ _

1.2

i

To

55

5.5

68

18 ______

1.5

0.9

59

1.5

2.0 __ _

60

3.0

64

24.7 _ __ -

3.3

0.4 __ __-

1.7

50

20

1.6 -----

60 __ __.

1.6

60 _- - -

11.6

1.3

1.0

67

2.6

2.5

1.65

Reported 

investment 

(millions of

dollars)

470

200

600

291

150 __ .

_ _ 1,711 _ .

100

400

.__ _ 500+ _ __.

900

145

471

______ 1,516+ ____

90

327

96

513 _ _

175

18

72

_____ 265+ ___-

1,200 __

1,842

1,230

430

4,702 +

1,397

1,398

_ __ 2,795+ ____

Ore in 

development 

(millions

of tons)

900

230

7,000

50

55

475

1,020

205

70

190

700

10

610

7

110

3,300

24,000

100

1,870

1,065

1 For bauxite, percent AlaOa; for gold, oz/ton.

2 Some low-grade gold ores contain uranium.

3 Also contains silver values.

4 Includes Greenland.

6 Includes complex ores that contain silver, lead, zinc, and copper.

RECENT RESEARCH ON MINING AND EXTRACTION

Research into various aspects of solution mining, 

or leaching, has advanced from laboratory and field 

tests to commercial operations, and in the future 

solution mining will be an alternative to conventional

mining in some areas. This technology has made possible the recovery of copper from some deposits 

hitherto considered uneconomic, and it is being used 

successfully in treating gold ore. A principal disadvantage of the method is that it does not recover
ROLES OF INDUSTRY AND GOVERNMENT IN RESEARCH 11

such important byproducts from copper ores as gold, 

silver, selenium, and tellurium.

The technical and economic feasibility of deriving 

aluminum from large domestic alunite deposits in the 

Western States and from high-alumina clays in 

Georgia is under serious study. Domestic aluminous 

laterites from deposits in Oregon have been used 

successfully instead of bauxite in a conventional 

alumina refinery.

Offshore exploration for deposits of manganese 

nodules, which also contain appreciable quantities 

of copper, nickel, and cobalt, has attracted worldwide attention, particularly by interests in the 

United States, Germany, Japan, and the U.S.S.R. 

These nodules have great potential value, and the 

technology to gather them from the deep seabed 

(4,000-6,000 metres) is rapidly being developed. If 

a satisfactory legal regime can be forged that will 

protect the miner's investment, commercial manganese nodule production will likely be operable 

before 1980.

Other significant results of scientific and engineering investigations in developing technology for extracting, processing, and recycling minerals, metals, 

and fossil fuels are summarized in U.S. Bureau of 

Mines (1974a).

ROLES OF INDUSTRY AND GOVERNMENT IN 

RESEARCH

For many reasons the ultimate objectives of industry's and Government's research in mineral resources 

lie at the ends of diverging paths. The mineral industry is composed of specialized units focused on 

individual or small groups of commodities, each of 

which has different search and development problems. The industry is so highly competitive and independent in operation, even for the same commodities, that no national focus has been possible beyond 

those imposed by supply and demand. The primary 

purpose of a private company is to find ore and provide a marketable product at a profit. A large part 

of industry's exploration activity is therefore directed toward developing reserves, generally from 

identified subeconomic resources and only to a much 

more limited extent from hypothetical and speculative resources. A company is understandably most 

concerned with its position in the short-term marketplace, whereas Government is deeply concerned with 

developing knowledge about the Nation's long-term 

total resource potential and its options for access to 

resources in the short term. The overall balance in 

treatment and understanding needed for publicpolicy decisions cannot be achieved by industry alone,

as industry concentrates its efforts on specific commodities and possibly overlooks others.

In recent years the cost in time and money of exploring for ore and developing reserves has increased 

markedly; at the same time the rate of discovery has 

decreased markedly. These factors have contributed 

materially to a reduction in domestic supplies and to 

price fluctuations which have resulted in overall reduction in funds available to industry for activities 

in mineral exploration. Some of these difficulties 

stem from Government actions. Even if industry 

funds were available, the costs are becoming too 

great to tolerate continued duplication of uncoordinated effort. Thus Government has the option to 

nurture the supply system through incentives to 

industry as a whole for increasing exploration activity and efficiency through mineral research and 

development.

A responsibility of Government is to collect, synthesize, and analyze basic data about mineral resources and to make the information available to 

those who need and want such information for making both public and private decisions. A broad base 

of data is needed by large and small mining companies for development of new target areas for 

exploration and new exploration and production 

methods. Planners also require it for determining 

quantitative analysis of the geologic and economic 

availability of national and international mineral 

supplies. In the years ahead, it will be increasingly 

necessary for Government to have a reservoir of 

information for planning purposes and to be able to 

monitor supplies and sources of supply, as well as 

uses of minerals at home and abroad, in order to help 

the Nation and its mineral industry across the inevitable economic highs and lows.

MINERAL RESOURCES RESEARCH PROGRAMS 

IN THE U.S. GEOLOGICAL SURVEY

The U.S. Geological Survey conducts mineral resources research programs in several of the organizational units shown in figure 2. The focus of this 

report is on those nonenergy programs that include 

the development and testing of resource theory and 

its application to improved appraisal and discovery 

technology; the development of resource information 

systems; and the analysis of these data to locate new 

resource targets and to provide forecasting and monitoring capabilities. These activities are supported 

by analytical laboratory facilities and by programs 

in geophysical and geochemical laboratory and field 

research, mineralogic and petrologic research on oreforming environments, and development of new tech-
12 MINERAL RESOURCE PERSPECTIVES 1975

niques for geochemical and geophysical exploration. 

Other very important resource programs which are 

not discussed within the scope of this report include: 

(1) those for energy materials such as oil and gas, 

coal, uranium, thorium, and oil shale; (2) studies 

directed specifically toward environmental impacts 

of mining; (3) detailed mining engineering studies 

of leasable mineral commodities on Federal lands; 

and (4) hydrologic studies that support resource 

appraisal and development.

U.S. Geological Survey mineral resource research 

programs collect and interpret Earth-science data in 

order to define the origin and occurrence of useful 

materials and to appraise the current and future 

availability of mineral resources in the United States. 

These programs lead to the definition of regions 

that seem likely to contain ore deposits, but not to 

their exploration or development as ore bodies which 

is the responsibility of the private sector. Incentives, 

however, to increase domestic exploration for selected minerals are provided to private companies 

through an exploration loan program and through 

research to improve exploration technology.

Knowledge about the geologic availability of domestic and overseas mineral resources is the first

link of a chain leading to discovery of ore deposits; 

this knowledge is basic to the development of sound 

Government policy decisions, and it fosters timely 

production of minerals by industry. U.S. Geological 

Survey programs aim to provide this kind of knowledge through four concurrent and continuing types 

of research:

Investigations of the geologic environment of 

mineral occurrence. These studies are aimed at 

obtaining basic information about known mineral 

occurrences that will help in identifying new exploration targets and accelerating the conversion of 

undiscovered mineral resources into reserves. They 

include (a) geologic, geochemical, and geophysical 

field investigations in known mining districts as well 

as in broad regions and mineral belts, and (b) geochemical laboratory research on the ore-forming 

environment and the processes of ore deposition. 

Clues to the location of a deposit can be established 

from the characteristics of occurrence and mode of 

formation of similar deposits. Geologic research involves documenting type examples of metal-mining 

districts and the detailed examination of mineralized 

rocks and the processes that form them. Research 

that synthesizes geochemical, mineralogic, and petroLand Information 

and Analysis Office Conservation Division Geologic Division Water Resources Division

^/Office of Energy Resources//

I

ANCILLARY OFFICES

Geology/-^

Office of 

Resource Analysis

Office of 

Mineral Exploration

FIGURE 2. Organizations in the Geological Survey having program responsibilities for mineral resources research. Primary responsibility for programs described in the report are indicated by stipple patterns, shared and supporting program 

responsibility indicated by line pattern.
MINERAL RESOURCES RESEARCH PROGRAMS IN THE U.S. GEOLOGICAL SURVEY 13

logic field and laboratory work aims at evaluating 

sources of ore-forming solutions, how the solutions 

move, and establishing the conditions favorable for 

ore deposition.

Geologic studies in potentially mineralized areas. 

These studies are aimed at applying basic resource 

information and multidisciplinary field techniques to 

the appraisal and discovery of resources in potentially mineralized areas. The objectives are to develop 

greater competence in rapid and accurate resource 

appraisal, to provide information needed for decisions about using potentially mineralized land, to 

identify new geologic targets to explore for conventional as well as new types of ore deposits, and to 

make quantitative studies of the resources of critically short commodities. Reports on this work are 

increasingly sought where Federal, State, and private lands are available for exploration by industry 

or involve Government management of leases; they 

are also needed when land-use and environmental 

impact decisions are being made prior to urban development of areas that may contain minerals of 

potential commercial value. Programs of this sort 

are also conducted by the U.S. Geological Survey in 

other countries under the auspices of USAID or contracts negotiated by the Department of State with 

other national governments, and have three benefits: 

(a) They assist foreign governments in on-the-job 

training of geologists and in development of mineral 

exploration programs, thereby speeding discovery 

and appraisal of the country's resources; (b) they 

add to basic knowledge of mineral deposits that can 

then be applied to the search for similar deposits in 

the United States; and (c) they provide opportunities for the evaluation of foreign resources and their 

potential impact on domestic supply.

Research in mineral exploration technology. 

These programs integrate geologic, geochemical, and 

geophysical concepts and data gathered both in the 

laboratory and in the field to develop and field-test 

new methods for assessing mineral resource potential as well as those for finding minerals, especially 

in new deposits and districts. Computer technology 

is used to process and aid in interpreting field and 

laboratory data.

Resource analysis. Programs of analysis using 

computerized data systems permit storage and categorized retrieval of information obtained from Government and industry. Analysis includes testing and 

evaluating computer programs for specific application to improving resource appraisals; to designing, 

developing, and testing predictive models of resource 

occurrence for use in economic studies of the conversion of resources into reserves; and to continual 

updating of resource-data banks.

Results of all these programs are published as reports and maps that provide the public with a continuously expanding base tff resource-related information. The principal publications of the U.S. Geological Survey are Professional Papers, Bulletins, 

Circulars, and various series of maps. Information 

is also made available in open-file reports or published in professional scientific journals. Reports 

and maps released by the Government are described 

in a monthly listing, New Publications of the Geological Survey, which is free upon application to the 

U.S. Geological Survey, National Center 329, Reston, 

Va. 22092.

In addition to the four types of continuing research, and the extensive technical support required 

by that research, the U.S. Geological Survey is 

committed to certain prescribed objectives based on 

statutory acts (such as giving advice to the Government and response to Congressional mandates) and 

on contractual agreements between the various parts 

of the Survey itself or with outside agencies (such 

as projects financed jointly with the National Science Foundation or with State agencies). The prescribed objectives are annually becoming a larger 

part of the Survey's mineral resource research program, and their fulfillment is possible only because 

of a substantial past investment in continuing scientific research backed by effective technical support.

Work at the operating level is organized into individual projects that may be concerned with one 6r 

more of the four major types of research. Some projects are regional in scope; others are more localized, 

intensive topical studies. These projects are described individually in the Science Information Exchange of the Smithsonian Institution, Washington, 

D. C. The current status or noteworthy achievements of projects are reported in Geological Survey 

Research 1974, U.S. Geological Survey Professional 

Paper 900. A brief summary of current mineral resource programs follows.

REGIONAL APPRAISAL

Regional resource mapping programs in geology, 

geophysics, and geochemistry are conducted in the 

United States as well as overseas. Increasingly, the 

successful and productive programs are multidisciplinary efforts. Characterization of resource potential depends on a geologic map framework that in 

turn is based on factors such as isotopic geochronology, geochemical distribution, and aeromagnetic map features. These programs are designed
14 MINERAL RESOURCE PERSPECTIVES 1975

to broaden the base of resource-appraisal theory and 

to provide answers about resource potential of large 

areas.

Regional resource appraisal is receiving new emphasis now because of the Wilderness Program on 

Forest Service lands and studies of Indian and 

Bureau of Land Management Interior lands (see 

p. 17). The Alaska Native Claims Act of 1974, 

for example, requires resource availability decisions 

for 80 million acres to be made within a 5-year 

period. In the Tucson area of Arizona, where mining and urban development interests are competing 

for the same lands, an assessment of potential copper resources has been made. Several mineral belts 

or regions in Nevada, Oregon, Colorado, and New 

Mexico are being examined at the 1:250,000 scale 

(2° quadrangle). The potential for developing new 

exploration targets of critical commodities such as 

platinum, nickel, copper, and chromium associated 

in ultramafic terranes is the basis for regional 2°- 

quadrangle appraisal mapping in California, Oregon, 

Minnesota, and Michigan. Gold- and silver-bearing 

volcanic rocks of Nevada are also being examined 

in detail.

Aeromagnetic and gravity methods have long been 

used singly or in combination to analyze the regional 

framework and to identify major rock types that 

may contain mineral resources. Under the national 

aeromagnetic map program, the U.S. Geological 

Survey, along with cooperating State agencies, added 125,000 square miles of magnetic coverage in 

1973. The work was done mainly by private contractors. Aeromagnetic maps are now publicly available, or are in press, for 40 percent of the Nation, 

including complete coverage of ten states Arizona, 

Colorado, Connecticut, Indiana, Iowa, Maryland, 

Massachusetts, Michigan, Minnesota, and Virginia. 

The flight-line spacing on these maps ranges from 

reconnaissance of 5 miles (about 8 kilometres) down 

to 1 mile (1.6 kilometres),' which is well suited for 

helping to define mineraj prospects. The truck-borne 

magnetometer has been effective as a rapid and 

economical means of examining the magnetic "signature" of an area, which is used in planning aeromagnetic work, or for detailed evaluation of specific 

anomalies shown on existing aeromagnetic maps.

AREAL GEOLOGIC STUDIES

Areal geologic studies are aimed at defining broad 

mineral belts that contain conventional types of deposits and new types of resource possibilities. Precambrian shield areas, for example, are sources of 

many mineral resources elsewhere in the world, but

they have not been extensively' explored in the 

United States except for iron; therefore, studies of 

stratigraphy, structure, and chemical facies of Precambrian iron formations and greenstone terranes 

in the Great Lakes shield and elsewhere are underway. Similarly, areas containing post-Precambrian 

crystalline volcanic rocks are being examined for 

possible massive sulfide deposits; carbonate platform rocks are being examined as stratigraphic 

traps for base metal deposits of the Mississippi 

Valley type; coastal plain sedimentary rocks 

and local placer deposits are being examined for 

high-alumina clay and titanium deposits; areas 

containing porphyry-type disseminations are being 

examined for copper and uranium; and new or 

extensions of old mineral belts containing hydro- 

.thermal vein and manto-type deposits are being examined for base and precious metals.

DETAILED STUDIES IN MINING DISTRICTS

Detailed studies in mining districts have long been 

a cornerstone of resource research t'o define oreforming environments, and they continue to be a vital 

part of the program. Data on the geologic characteristics of a new type of low-grade disseminated 

copper-silver deposits at Spar Lake,, Montana, in 

Precambrian quartzites will provide the basis for 

future exploration as the need for such deposits develops. Studies of low-grade disseminated gold deposits of the Carlin type continue; discovery of these 

deposits opened new opportunities for preciousmetals exploration in similar geologic terranes elsewhere. Porphyry deposits are the major source of 

copper in the United States and are producers of 

important quantities of molybdenum, gold, and some 

base metals. Extensive studies of this type of deposit 

in both production and exploration phases are in 

progress at Ray, Arizona; in Puerto Rico; and in 

the Cathcart Mountain area, Maine.

Research on natural processes that produce ore deposits continues in the east Tennessee zinc district 

and the San Juan Mountains of Colorado. Both 

studies are concerned with understanding spatial relationships, the chemical and thermal nature of solutions, their plumbing systems, and the sources of 

metals that were concentrated.

Investigations of the geochemistry of ore deposits 

provide new insights into the processes responsible 

for anomalous concentrations of minerals. Continuing laboratory studies of mineral-phase equilibria 

have yielded information regarding physical and 

chemical conditions at the time of ore deposition. 

Field and laboratory studies are directed toward
MINERAL RESOURCES RESEARCH PROGRAMS IN THE U.S. GEOLOGICAL SURVEY 15

understanding the source of metals, the mode of 

transportation, and the reasons for localization of 

the metals. For example, mineralogic and sulfur 

isotopic studies at Homestake, S. Dak., have shown 

that gold can be related to original sedimentary accumulations, thereby enlarging the area of search 

for additional deposits.

GEOCHEMICAL EXPLORATION

Geochemical exploration programs are based on 

the systematic measurement of one or more chemical 

properties of naturally occurring materials, and the 

discovery and delineation of chemical patterns that 

may be related to potential mineral deposits. One 

approach to a better understanding of how geochemical exploration can be more useful in the 

search for mineral deposits is to evaluate and compare data from various kinds of samples (rock, soil, 

stream sediment, gases) collected in known mineral 

districts or from other localities thought to have a 

high potential for new deposits. Such investigations 

are under way in a variety of climatic environments 

(humid-tropical, humid-temperate, arid, and alpine). These studies will help to establish the best 

type of sample to collect in order to find a particular 

type of mineral deposit in a particular climatic environment.

Other geochemical investigations are oriented toward model studies of individual mineral deposits or 

mineral districts. These studies characterize the patterns of major, minor, and trace elements found in 

rocks in and around known mineralized areas. The 

characteristic chemical dispersion patterns can then 

be searched for in other areas to locate new deposits, 

especially those that are deeply buried under rock, 

soil, water, and ice.

Other studies deal with the chemical effects of 

weathering processes on mineral deposits and how 

these changes can be used to locate new deposits. 

Studies of the abundances of various trace elements 

in vegetation, in surface and ground waters, and in 

specialized types of samples such as chemically precipitated coatings on rock surfaces and gases in the 

atmosphere and soils should provide a better understanding of how various chemical elements move 

under natural conditions and, therefore, how geochemists can best use this information in the search 

for new mineral resources.

Studies are also being conducted in the application of computer technology to geochemical data. 

Many surveys now involve the analysis of thousands 

of samples for as many as 30 or 40 separate chemical elements. Such a large set of data can be evaluated adequately only by computer. New statistical 

and graphic concepts are also being applied to geochemical data sets to evaluate with greater confidence the mineral resource potential of selected 

areas in the United States. New analytical methods 

being tested are needed to fulfill the new search 

specifications. The emphasis is on methods that are 

cheaper, faster, and more accurate. Many chemical 

elements that in the past were not routinely sought 

in samples can now be determined, thereby increasing the possibilities of finding new resources of these 

elements.

GEOPHYSICAL EXPLORATION

Geophysical exploration is aimed at the detection 

of subsurface mineral deposits where drilling and 

excavation are prohibitively expensive but where 

rapid appraisal of the possibilities for the occurrence of mineral resources is required. The capabilities of several geophysical methods are currently 

being tested and evaluated.

Magnetic anomalies may denote unmapped or 

blind intrusive bodies that have associated mineralization, such as the porphyry copper deposits at 

Ruth, Nev., or they may directly reflect iron ore deposits, as at Marmora, Ontario. Negative anomalies 

also may be significant where the magnetite content 

of the host rock has been greatly reduced by hydrothermal alteration associated with ore emplacement, 

as at Cripple Creek, Colo.

Electrical resistivity and' electromagnetic surveys 

provide additional information about target areas 

delineated with gravity and magnetic surveys, particularly in the identification of buried conductors 

which are indicative of massive sulfide deposits or 

in locating buried channels that may control uranium deposits.

Radioactivity surveys are used not only to detect 

radioactive minerals directly but also for correlation 

of rock units in geologic mapping. Gamma-ray spectrometers can be used to discriminate between radiation from uranium, thorium, and potassium sources. 

For example, radioactive potassium associated with 

hydrothermal alteration that occurred during mineralization can be studied.

Several methods for measurement of natural earth 

currents are proving to be useful and economical 

reconnaissance techniques in exploring for conductive anomalies that may be associated with geothermal systems, which are in turn associated with 

large self-potential anomalies. These methods offer promise for the development of improved mineral resource exploration techniques for the future.
16 MINERAL RESOURCE PERSPECTIVES 1975

Remote-sensing experiments using a multispectral 

4-band camera and thermal infrared scanner are 

underway over areas of known base-metal and 

uranium mineralization to study resolution of subtle 

surface-alteration patterns. In studies of the Goldfield area in Nevada, a combination of digital computer processing and color compositing of LANDSAT multispectral scanner images were used to 

enhance spectral reflectance differences; hydrothermally altered areas associated with mineral deposits 

were detected and mapped (Rowan and others, 

1974).

The technique of total-field resistivity mapping 

promises to be a rapid yet good-resolution reconnaissance approach for deep resistivity studies. An 

improved electromagnetic technique designated ELF 

(extra low frequency) is being developed which uses 

a ground transmitter as a multiple-frequency source 

and an aircraft to carry the receiver. In addition to 

providing a reliable signal along with rapid, systematic coverage, the depth of penetration for a 

large target is about 500 metres in areas of resistive 

country rock.

The application of paleomagnetism to the study 

of time and sequence of uranium deposition is being 

investigated. Samples of the ore zones, alteration 

halos, and host rocks are analyzed to detect significant variations in magnetization relative to varying 

intensities and directions of magnetic fields in past 

geologic history.

Progress is being made in interpretation of geophysical data using electronic computers. Highly effective computer programs for automatic interpretation of two- and three-dimensional models from 

both d.c.-resistivity and electromagnetic data are 

being developed, such as techniques for making automatic depth determinations and for calculating the 

pseudogravity field from magnetic data. More rigorous mathematical treatment of filtering is being applied to magnetic data in an attempt to separate 

superimposed magnetic anomalies, the sources of 

which are at different depths below the surface. This 

should aid in detecting buried stocks that may be 

mineralized in areas where volcanic rocks are at the 

surface.

RESOURCE ANALYSIS

Research in resource analysis is a relatively new 

component of the mineral resource appraisal program. The primary emphasis is on improving data 

storage and retrieval capability and developing systems for resource estimation and prediction. The 

development and expansion of the computerized resource information bank (CRIB), which is the primary storage and retrieval system for mineral resource information in the U.S. Geological Survey 

(Calkins and others, 1973) is focused on insuring 

CRIB's compatibility with data systems in other 

State as well as Federal agencies. Application of 

computer graphics to geologic-data solutions and 

displays is also being examined. Geostatistics and 

computer theory are applied to seeking mathematical 

models of resource occurrences, the economics of 

the exploration process, and resource convertability 

to reserves.

MINERAL RESOURCE STUDIES BY SPECIALISTS

An integral part of the mineral resource appraisal 

program is an intensified emphasis on long-term 

studies of specific critical commodities an approach 

to resource studies that has served the Nation effectively in the past. The comprehensive assessment 

of resources of each mineral commodity on a nationwide scale, presented in Professional Paper 820 

(Brobst and Pratt, 1973), could not have been prepared without the specialized knowledge of several 

dozen commodity experts, each of whom had devoted a major part of his professional career to 

field, laboratory, and library research on the economic geology of one or a few mineral commodities.

Understanding of the U.S. resource base now requires global resource knowledge. In addition to establishing priorities for national commodity-study 

emphasis, the specialist program provides opportunities for field studies at home and abroad, laboratory support, and technical services to broaden 

the experience and competence of individual specialists.

Mineral resource specialists assigned to all the 

commodities of national significance must maintain 

up-to-date mineral information for program planning as well as for advisory purposes. Commodities 

currently covered by the mineral-resources-specialist 

program are listed in table 4.

STATE REPORTS REQUESTED BY THE U.S. SENATE

The first of the modern Federal documents on 

the mineral and water resources of various States, 

prepared at the request of the Interior and Insular 

Affairs Committee of the U.S. Senate, was the U.S. 

Geological Survey report on Wyoming submitted to 

Senator Gale McGee in 1960. Between 1963 and 

1974 the Geological Survey, at Senatorial request, 

provided reports on Montana, Alaska, Colorado, 

Idaho, Nevada, South Dakota, Eastern Montana,
MINERAL RESOURCES RESEARCH PROGRAMS IN THE U.S. GEOLOGICAL SURVEY 17

TABLE 4. Commodities in the mineral-resources-specialists 

program

Aluminum

Barite

Beryllium

Boron

Bromine

Chromium

Clays

Copper

Feldspar

Fluorine

Gold

Graphite

Iron ore

Kyanite

Lead

Lightweight aggregates

Limestone and dolomite

Lithium

Mercury

Mica

Molybdenum

Nickel

Niobium

Nitrates

Peat

Phosphate

Platinum-group

Potash

Rare earths

Rhenium

Salt

Scandium

Silver

Stone, construction

Sulfur

Talc

Tantalum

Tin

Titanium

Tungsten

Vermiculite

Zeolites

Zinc

New Mexico, Washington, California, Missouri, Oregon, Arizona, Utah, and North Dakota. With the 

exception of the original Wyoming report, these 

were prepared by the U.S. Geological Survey in collaboration or cooperation with the respective State 

geological or mining agencies, and in some cases 

with State universities or other Federal or State 

agencies, such as the U.S. Bureau of Mines and 

Bureau of Reclamation. All were published originally as U.S. Senate Documents or Committee 

Prints, but some were reprinted separately as reports of the various State agencies. Because of limitations of staff and the short time available for 

preparation (generally only a few months), these 

reports have not entailed new field surveys but 

have relied on the collective experience of numerous 

professionals in the various agencies.

Early in 1974, the U.S. Geological Survey was 

requested to revise and update the report on South 

Dakota, originally published in 1964. These reports 

are a long-term obligation that has been met as 

Survey staff, funding, and scientific support from 

respective State geologic agencies became available.

MINERAL APPRAISAL OF FEDERAL LANDS

Appraisal of the mineral resources of Federal 

lands is the responsibility of the Government and

was a cardinal point in the legislation that created 

the U.S. Geological Survey. In the past, legislation 

of two types has directed such appraisal. The Mineral Leasing Acts of 1920 and 1947 provided for the 

appraisal of identified leasable minerals energy 

minerals, potash, sodium, phosphate, and sulfur on 

Federal lands. The Wilderness Act of 1964 provided 

for the appraisal of mineral resources of all types

on primitive and wilderness-type lands prior to their 

withdrawal from future mineral entry. Currently, 

the anticipation of increased monetary returns from 

mineral leasing under the proposed act to replace the 

Mining Law of 1872 emphasizes the need for systematic appraisal of mineral resources of all Federal 

lands.

Federally owned or federally managed lands comprise about 762 million acres, or about one-third of 

the Nation. Almost half of the federally-owned lands 

(353 million acres) is in Alaska; almost 90 percent 

of the remainder (358 million acres) is in 11 western 

States (table 5), and about 43 million acres of that 

lie in States east of the Rocky Mountains. The principal agencies responsible for management of Federal lands are shown in table 6. The Bureau of 

Indian Affairs manages about 50.5 million acres of 

Indian lands, which are not federally owned.

TABLE 5. Federally owned land in 11 western States and 

Alaska as of June 30, 1971

[From U.S. Bureau of Land Management, 1972]

State

California _ _ __ _

Idaho _ _______ _ _

Utah __ __ _ _ _ __ __ _ __

Wyoming _ _

Total in 11 Western StatesAlaska

Federal lands 

(millions of 

acres)

31.9

44.9

23.9

33.8

27.6

60.8

26.0

32.2

34.8

12.6

30.0

358.5 

353.5

Percent of 

total area 

of State

44.0

44.8

36.0

63.8

29.6

86.5

33.5

52.3

66.0

29.6

48.1

96.7

TABLE 6.- -Major landholding agencies in the Federal Government

Agency Millions of acres 1

Department of the Interior

Bureau of Land Management 474. 

Bureau of Sport Fisheries and Wildlife __ 27.9 

National Park Service 24.5 

Bureau of Reclamation _ _ _ 7.6 

Bureau of Indian Affairs a 2.2

Department of Agriculture

Forest Service ____ 186.8

Department of Defense ___30.3

1 As of June 30, 1971 (from U.S. Bureau of Land Management, 1972).

2 As of June 30, 1973 (from Counselman, 1973) : does not include 50.5 

million acres of Indian-owned lands managed by B.I.A.

Minerals from the Federal lands have contributed 

markedly to the industrial and economic development 

of the Nation and can be expected to continue to do 

so. According to the U.S. National Commission on 

Materials Policy (1973, p. 79), "In 1965 the western 

Public Lands produced over 90 percent of the Nation's domestic copper, 95 percent of the mercury
18 MINERAL RESOURCE PERSPECTIVES 1975

and silver, and 100 percent of the nickel, molybdenum, and potash, and about 50 percent of the 

lead." Oil and gas production from onshore Federal 

and Indian lands has supported 5 to 6 percent of 

the Nation's total domestic energy production in the 

recent past. During fiscal year 1974, receipts from 

all energy and mineral leasing activities conducted 

by the Bureau of Land Management, including 

rentals, royalties, and bonuses from lands and from 

the Outer Continental Shelf, totalled about 7 billion 

dollars.

Not all Federal lands are open to mineral exploration development. As of June 30, 1967, more than 

111 million acres had been withdrawn from mining, 

and more than 103 million acres from mineral leasing. Most of the withdrawn lands are in National 

Parks, Monuments, Fish and Wildlife Game Refuges, 

Indian Reservations, reclamation projects, military 

reservations, and scientific testing areas. The Wilderness Act of 1964 provides that areas designated 

as Wilderness will be withdrawn from mining laws 

and mineral leasing activities by December 31, 1983. 

Other lands not subject to leasing are the Naval 

Petroleum and Oil Shale Reserves, the National 

Park System, and a one-mile buffer zone around 

Naval Petroleum, oil shale, and helium reserves. In 

total, the Federal lands subject to mineral development aggregate about 822 million acres, including 

public lands not withdrawn, acquired lands, and 

lands which have been patented with minerals reserved to the United States. Submerged lands of the 

Outer Continental Shelf are also subject to mineral 

development.

Once resources are identified on Federal land, the 

Bureau of Land Management and the Forest Service 

have the main responsibility for administering the 

laws concerning leasable and locatable minerals. 

Leasable minerals include energy minerals and potash, sodium, phosphate, and sulfur. Locatable minerals include those metallic and nonmetallic minerals 

that may be located under the Mining Law of 1972. 

Mineral materials, largely sand, stone, gravel, pumice, and clay, are obtainable by competitive sale by 

contract. The U.S. Geological Survey is responsible 

for classification of public lands for their leasable 

mineral resources for retention-disposal, exchange, 

and multiple-use purposes. The U.S. Geological Survey is also responsible for prelease resource evaluation and postlease administration of leasable minerals.

In its statutory role to assess mineral resources 

on Federal lands the U.S. Geological Survey currently provides three levels of resource appraisal of

specific tracts of Federal lands, depending on the 

time, personnel, and funds available (table 7). Level 

I is a library and record analysis that provides 

enough data to delineate those areas that are known 

to have promising mineral potential but is inadequate to form the basis for decisions about the disposition of lands. Level II is a more extensive investigation, including field reconnaissance, which 

evaluates the mineral potential of areas and designates potential targets for detailed studies or exploration for possible future development. These results are adequate for making land-use decisions 

with regard to mineral potential but not for leasing purposes. Level III consists of detailed studies 

required for resource evaluation and lease management decisions and mineral resource research on 

mining districts. Research at this level not only increases our understanding of the genesis, distribution, and economic potential of metallic and nonmetallic resources, but also contributes to the development of modification of exploration tools and 

techniques. The cost of these levels of appraisal 

varies depending on the degree to which an area has 

already been developed, the amount of available geoscience data, the difficulty and expense of obtaining 

such data, and the length of time available to make 

the study.

Much remains to be done before the mineral resources on all Federal lands have been appraised. 

Table 8 shows the magnitude of the task ahead; 

much is known, however, about the geology and 

mineral resources in many as yet unappraised areas 

because of U.S. Geological Survey, State, industry, 

university, and other studies. When the status of 

knowledge on these areas is determined, it will be 

possible to revise table 8; nevertheless, the task will 

remain a formidable one. In addition, appraisals will 

eventually be needed for 50.5 million acres of Indian 

land. Finally, future planners must also bear in 

mind that much of the 1,600 million acres of privately owned lands, mostly in the eastern part of 

the United States, has never been adequately appraised.

Following are summaries of the principal current 

U.S. Geological Survey programs directed wholly or 

in part toward mineral resource appraisal of Federal lands, exclusive of the continuing mineral classification program.

Wilderness Program. The U.S. Geological Survey and the U.S. Bureau of Mines jointly have conducted mineral surveys on wilderness and proposed 

wilderness areas in National Forests under the 

Wilderness Act of 1964. The Survey evaluates the
MINERAL RESOURCES RESEARCH PROGRAMS IN THE U.S. GEOLOGICAL SURVEY 19

TABLE 7. Three levels of resource appraisal used by the U.S. Geological Survey

Level Objective Method of study Advantages Limitations

I__ General inventory of past 

production and resource 

activity.

Identify areas needing 

more detailed study.

II_-- Uniform reconnaissancelevel appraisal to establish base for total resource estimate.

Ill __ Sufficiently detailed geoscience data to determine 

reserves and to make 

management decisions 

regarding leases and environmental consequences.

Library and records survey; 

search of all sources for 

unpublished data on 

known districts; computer 

storage of data.

Level I plus reconnaissance 

geologic, geochemical, and 

geophysical mapping; remote sensing; sampling 

of broad areas that are 

promising. Computer storage, retrieval, and interpretation of data.

Detailed geologic mapping, 

geochemical sampling and 

assaying, and geophysical 

surveys in small areas of 

known potential.

Computer storage, retrieval, 

and interpretation of data.

Status report: assessment 

of all known resource information. Important first 

step for any assessment.

Sufficient detail to present 

resource evaluation for 

use of decision makers. 

New areas identified for 

classification and development.

Development of geologic 

theory leading to identification of new types of deposits; basis for stockpile 

decisions.

Superficial; most data will 

be spotty; inadequate for 

determination of total resource; often biased; undeveloped areas will be 

overlooked.

Not sufficient to define reserves or to be used by 

management.

Deeply buried deposits 

missed.

Time consuming, expensive.

TABLE 8. Mineral resource appraisal of Federal lands completed to September 1974

Federal land area

Federal lands appraised at Level I

Desert lands (Bureau of Land Management) 

Urban areas,1 San Francisco, California __ 

Federal lands appraised at Level II

^TilHpvnpciti InnHc: ^T^nvpctf SPWIPP^

TTvViJin JITPJIC * T^n^Qfin AviyntiQ

Quadrangle appraisal mapping *

Federal lands appraised at Level III 2

Millions 

of acres

762

80

1 

1

15.4

5

2

undetermined

1 Includes some Indian and (or) private lands.

2 The status of extensive U.S. Geological Survey mineral classification 

programs of the past 70 years, which routinely provided data about the 

potential mineral resources of Federal lands to Federal land-administering 

agencies, is not tabulated in this compilation.

mineral potential of the areas on the basis of reconnaissance geologic, geochemical, and geophysical examinations. The Bureau evaluates all previous and 

existing exploration and mining in the area, including examination of all mining claims. In addition, a 

minability appraisal is made where appropriate.

As of September 1974, 447 primitive, wilderness, 

and proposed wilderness areas totaled about 38.7 

million acres; 129 areas, about 15.4 million acres, 

had been evaluated. Studies of the remaining areas 

are scheduled to be completed by January 1, 1983. 

In January 1975, 16 new wilderness areas, totalling 

212,618 acres of the Eastern United States, were 

established, and 17 proposed wilderness areas were 

designated for study.

Desert land studies. An evaluation of the geology 

of the Randsburg-Searles Lake area, California, is 

the first of several studies that will provide information on the known mineral resources and mining

activities of the area, which information will be 

used by the Bureau of Land Management as a basis 

for classifying these Federal lands for protection 

of the desert environment. Less than 1 million acres 

have been appraised in this new program.

Urban studies. Reconnaissance geologic mapping 

and compilation of previous geologic work is being 

conducted in the Tucson area, Arizona, much of 

which is composed of Federal or Indian lands. Data 

on the mineral potential are based on past production and unpublished material contributed by the 

mining industry. The resulting maps will provide 

State and local planners with factual data for landuse decisions. Southeastern Arizona is one of the 

world's richest copper provinces, and it currently 

faces the problems of industrial growth, urbanization, and protection of environmental values. Approximately 5 million acres have been examined in 

this program.

Quadrangle appraisal mapping. Reconnaissance 

mapping and local detailed mapping of selected 2° 

quadrangles, large segments of which are Federal 

lands, include extensive geophysical surveys and 

some geochemical sampling. The studies are designed to test the potential of areas that have known 

promise as mineral belts and to determine parts of 

those areas that warrant more detailed studies, as 

well as to evaluate other geologic environments 

which elsewhere in the world have produced mineral 

resources.

Indian land studies. A new program to summarize existing information on the geology and 

mineral resources of Indian lands was begun in 

1975 in cooperation with the Bureau of Mines and
20 MINERAL RESOURCE PERSPECTIVES 1975

Bureau of Indian Affairs. Compilation of resources 

summaries of nearly 10 million acres of Indian lands 

is in progress. Some of these lands contain large 

resources of fuels and minerals, and their orderly development is essential to the welfare of Indian people and the Nation's economy.

Alaska land appraisal Alaska is almost equal in 

size to one-fifth of the total area of the conterminous 

United States. Although a large part of Alaska 

(353.5 of its 365.5 million acres) was Federally 

owned land as of June 30, 1971, the land ownership 

pattern is changing significantly. By 1978, as required by the Alaska Statehood and Alaska Native 

Claims Settlement Acts, the State will own 103 million acres and Natives will own 40 million acres. 

Proposals for adding about 80 million acres to the 

National Park, Wildlife Refuge, Forest, and Wild 

and Scenic River Systems have been submitted for 

Congressional consideration under provisions of the 

Alaska Native Claims Settlement Act. Much of the 

land included in these proposals may be withdrawn 

from mining and mineral entry even though some 

of it includes parts of potential mineral belts.

Because of these pending changes, the U.S. Geological Survey's Alaska mineral resource appraisal 

program is attempting to increase the rate of appraisal as well as its quality and scope. Started in 

July 1974, the program describes and evaluates 

energy, metal, and nonmetal mineral resources and 

their potential for discovery.

CONCLUSIONS: SOME PRESSING PROBLEMS

Because there are so many minerals, the related 

problems are even more complex than those for 

energy. The national and international flow of minerals, for example, and the possibilities for substitution of one mineral for another, are very complex 

phenomena that are not well understood. Public 

awareness of the need for many minerals has not 

yet been aroused because vital mineral uses are not 

obvious in a complex society, but sudden shortages 

would affect our personal lives in unforeseen ways. 

Prior planning and critical evaluation are as necessary to the development and utilization of nonfuel 

mineral resources as they are for the energy 

minerals, if potentially serious problems are to be 

avoided or at least minimized.

DETERMINING CRITICALNESS OF MINERAL 

COMMODITIES

Objective means of evaluating the overall national and international importance of each commodity must be developed so that priorities for research may be assigned to various commodities and 

to the most productive lines of research for each.

Factors to be considered include:

1. Importance of the commodity to industry and 

commerce,

2. Defense or other needs of overriding importance,

3. Extent to which the commodity can be replaced 

by others,

4. Extent of domestic reserves,

5. Extent of economic, technologic, and legal use 

of domestic resources,

6. Dependence on foreign imports, and

7. Political stability (internal or international) of

foreign import sources.

Every mineral commodity being mined today is 

essential to some industrial process or product, but 

to assume that either government or industry can 

fully pursue the research needed on all mineral 

commodities would be far from realistic.

DEPENDING ON IMPORTED MINERALS

Patterns in world mineral supply and demand

which had persisted for some four decades began 

to change radically after World War II. In 1940, the 

United States produced and consumed nearly 50 percent of world mineral supplies, including fossil fuel, 

but in 1971 the United States' share had dropped 

to about 27 percent, and it continues to diminish. 

Between 1945 and 1972, world consumption of 18 

basic mineral commodities increased about six times, 

whereas U.S. consumption less than doubled. Starting from a far lower per capita base, both the developed and the more advanced developing countries 

are catching up in industrial production. Furthermore, world population is multiplying rapidly, placing increasing demands on limited mineral supply. 

The United States continues to be ever more dependent on foreign sources of supply for essential 

mineral raw materials. In 1972 and 1973, our overall dependence on imports for 15 critical industrial 

materials other than energy was about 60 percent 

of our consumption (Council on International Economic Policy, 1974, figs. 2 and 15); the situation for 

individual materials ranged from total dependence 

to total independence. In 1974, the Nation was more 

than 90 percent dependent on imports of primary 

materials for four commodities, 75 to 90 percent 

dependent for 8 additional commodities, and 50 to 

75 percent dependent for 8 commodities. Seventeen 

other major commodities are imported. Forecasts for 

the year 2000 indicate that we shall then be completely dependent on imports for 12 commodities, 

more than 75 percent dependent for 19 commodities,
CONCLUSIONS: SOME PRESSING PROBLEMS 21

and more than 50 percent dependent for 26 commodities. Among causes of this increase are (a) 

the depletion of known domestic ore deposits, and 

(b) the "free market" economy, whereby it is 

cheaper to use imported supplies of some raw materials than to process and use our own, even 

though we may have ample supplies. The increasing dependence on imports seems inescapable but by 

no means approaches the degree of dependency of 

any other major industrialized country with the exception of the U.S.S.R., which is relatively self-sufficient in most essential commodities and which has, 

in the last five decades, made enormous investment 

in geologic research and prospecting in carefully 

planned programs.

Rapidly evolving complex changes in the attitude 

of people and nations foreshadow fundamental 

changes in economic patterns throughout the world. 

Sparked by rising national consciousness and economic pressures, the industrially underdeveloped and 

developing nations are increasingly less willing to 

export only raw materials and would prefer to export their mjneral materials in at least the semifinished stage. These nations possess many of the 

world's major mineral deposits, upon which the industrial world will depend during the next quarter 

century, and they are forming national companies to 

prospect for and exploit their ore deposits. Many 

highly industrialized nations, including France, Japan, and Germany, are actively supporting these 

national companies of the developing nations to insure continued raw material supplies for their own 

economies. Some industrialized nations, including 

those already mentioned, negotiate through their 

own government-supported industrial firms, thereby 

increasing government-to-government negotiations 

in this field.

In contrast, United States industry has not entered 

into comparable joint ventures with the Federal Government. The United States is thereby put into a 

less competitive position in negotiations abroad for 

access to available foreign supplies. And at the same 

time, environmental constraints on the activities of 

the mining and manufacturing industries in the 

United States are forcing a trend toward additional 

domestic dependence on foreign supplies of both raw 

and partly processed mineral products.

Some options available to the United States to 

insure adequate supplies of mineral raw materials 

from abroad include:

Diversification of overseas sources of supply. 

Government activities to assure access to foreign 

sources of supply, combined with steps by industry to increase overseas processing of raw 

materials.

A major economic stockpiling program by industry 

or Government for those commodities, including 

energy materials, supplies of which are dependent on a few foreign sources.

Restraint in consumption of the scarcer raw material supplies. Products and processes can be 

redesigned to use abundant rather than scarce 

materials.

National and worldwide programs for recycling of 

metals.

Bilateral technical assistance programs in mineral 

fields, financed by the United States.

Placement of staff trained in mineral deposit and 

mineral industry development in United States 

Missions overseas to insure accurate, up-to-date 

information on present and potential mineral 

supplies.

Fostering of close cooperation between Government 

and industry. The natural short-range view of 

industry, working toward an impressive balance 

sheet, must be melded with the natural longrange view of Government, working toward 

long continued economic and social progress and 

stability.

STATE OF THE MINING INDUSTRY

Keeping a finger on the pulse of domestic mining 

activities, an implied responsibility under provisions 

of the Mining and Minerals Policy Act of 1970, is 

very difficult because of the complexity of the mining 

industry. One possible* measure of the state of health 

of the industry is the amount of resource exploration activity, and present exploration activity can 

be considered a barometer of the future mining activity. A systematic quantified method to obtain this 

information should be developed jointly with the 

industry. Improved liaison will lead to the development of a more accurate resource data base.

REPORTING RESERVE DATA

The difficulty of making reliable estimates of 

mineral resources has been compounded by the longstanding, but declining, practice of many mining 

companies to maintain secrecy about the magnitude 

of their reserves in the ground. Public release of 

such data obviously could be disadvantageous to 

corporations in the competitive business atmosphere. 

Reliable reserve and resource estimates, however, 

are increasingly needed for use in making policy 

decisions both in corporate board rooms and Govern-
22 MINERAL RESOURCE PERSPECTIVES 1975

ment conference rooms. Adequate reporting of such 

information can be done in strictest confidence so as 

not to prejudice private interests.

RECOVERING POTENTIAL MINERAL BYPRODUCTS

Potential mineral byproducts or coproducts are 

being lost while their associated principal mineral 

products are being mined and recovered (Brobst 

and Pratt, 1973, p. 7-8). A few of these minerals 

are lost because of selective mining the gold, silver, 

selenium, and tellurium that remain behind during 

in-place leaching of copper deposits. Most of them 

are lost in selective processing vanadium in magnetite deposits; fluorine, vanadium, uranium, scandium, and rare earths in marine phosphorites; cadmium, bismuth, cobalt, and mercury in lead ores; 

and several metals in coal ash. Industry or public 

research and development are needed to identify 

these escaping resources and determine ways of recovering them. Other commodities that have potential for recovery as byproducts include aluminum and 

soda ash from oil shale; vanadium and nickel from 

crude oils;' gold and tungsten from sand and gravel 

operations; trace metals from brines and mine 

waters; an'd several metals from seawater and sea 

bed deposits.

CONSIDERING SUBSEA MINERAL RESOURCES

As offshore drilling for oil becomes more common, 

the potential for other mineral resources under the 

sea will receive more public attention. Neither the 

continental margins nor the deep seabed resource 

potentials can be ignored in future appraisals of the 

w.orld's mineral resources. The continental margins, 

being geologically part of the continents, contain in 

general the same kinds of resources as the continents and have contributed some mineral production, 

whereas the deep seabed, being composed largely of 

basaltic igneous rock covered by clays and other 

fine-grained sediments, contains a much smaller 

variety of minerals chiefly metals occurring in 

manganese nodules, pavements, and crusts, and deposits that are genetically related to mafic igneous 

rocks.

Minerals that have been produced from continental margin rocks mainly by means of shafts extending from on-land to beneath the seabed include 

coal, iron ore, nickel, copper, tin, gold, mercury, 

barite, and limestone. In recent years only coal, iron 

ore, and barite were being produced in significant 

amounts by this method. Barite, although a bedrock 

deposit, was mined from an open-pit operation beneath the sea.

Surficial deposits on the world's continental 

shelves include sand and gravel, calcium carbonate 

in the form of shells, precious coral, iron sands, 

placer deposits containing tin, diamonds, titanium 

sands, zircon, monazite, and gold and other heavy 

minerals, and phosphorite nodules. Sand and gravel 

is by far the most important by volume.

No minerals have yet been produced commercially 

from the deep seabed, but commercial manganesenodule production will likely begin before 1980. 

Metalliferous brines and muds also have some potential in the deep seabed, but little is known atfbut 

them, and any possible commercial recovery seems 

several decades in the future.

STAFFING FOR MINERAL APPRAISAL AND 

EXPLORATION

Continued appraisal of and exploration for mineral resources require a continuing supply of geologists, geochemists, and geophysicists as well as 

mineral economists. Student enrollments in these 

disciplines have decreased steadily in recent years, 

and at the same time employment demands have 

increased sharply.

Since the National Science Foundation's Register 

of Scientific and Technical Personnel was discontinued in 1970, no system exists for monitoring employment demands and predicting trends. Informal 

observations made to the American Geological Institute by university department heads, who are probably in the best position to observe where hiring 

emphasis is being placed from year to year, indicate 

a recent large upsurge in demand for Earth scientists, particularly at the Batchelor's and Master's 

levels, although the number of Master's candidates 

decreased by 4 percent and the number of Doctoral 

candidates decreased by 5 percent in 1974 (Henderson, 1974). Timely availability of adequate numbers 

of university graduates at various academic levels 

requires that employment needs be anticipated 2 

to 7 years in advance, but the mineral industry 

generally has not been able to anticipate its need for 

Earth scientists by more than a few years.

The level of exploration activity seems to be the 

index by which to measure the need for Earth scientists. Long-term increases in exploration activity can 

be anticipated reasonably because of the vast increase in mineral production that must occur during 

the next decade or so. Over the past 7 years, student 

enrollment evidently has conformed quite closely 

to demand or kept ahead of demand in a marketplace in which no mineral crises and no sudden large 

upsurges in mineral exploration activity have oc-
CONCLUSIONS: SOME PRESSING PROBLEMS 23

curred. Now, with the existing crisis in energy and 

impending crises for several metals, the educational 

process may not be able to keep abreast of demand. 

It seems likely that anticipated increases in mineralexploration activity may result in a near-term shortage of geologists and a chronic shortage of geophysicists and geochemists. The identification of new 

employment requirements and support for shortterm retraining programs are probably areas in 

which Government, alone or jointly with industry, 

can assist in meeting changing needs.

INCREASING PUBLIC AWARENESS

Finally, the popular misconception that a steady 

supply of minerals from the crust of the Earth is 

simply a matter of favorable economics and technology has induced widespread public complacency. 

This notion ignores that fundamental factor governing mineral supply: geologic availability. Neither 

technologic magic nor astronomical dollar value can 

make it possible to extract iron, aluminum, gold, 

sulfur, or phosphorus from rocks in which they are 

not present.

Our total resources in 1975 are vast, but they 

cannot be mined, much less used, until they have 

been identified, appraised, and finally moved into the 

category of reserves. We must begin now, in both 

industry and Government, to inform the public about 

the real nature of our minerals problem, and to 

stimulate the research that will make our mineral 

resources available.

REFERENCES CITED

Allais, M., 1957, Method of appraising economic prospects of 

mining exploration over large territories; Algerian Sahara 

Case Study: Management Sci., v. 3, no. 4, p. 285-347.

Arps, J. J., Mortada, M., and Smith, A. E., 1970, Relationship 

between proved reserves and exploratory effort: Soc. 

Petroleum Engineers, SPE paper 2995.

Bieniewski, C. L., Persse, F. H., and Brauch, E. F., 1971, 

Availability of uranium at various prices from resources 

in the United States: U.S. Bur. Mines Inf. Circ. 8501, 92 p.

Blondel, F. A. J., and Lasky, S. G., 1956, Mineral reserves and 

mineral resources: Econ. Geology, v. 51, no. 7, p. 686-697.

Brinck, J. W., 1972, The prediction of mineral resources and 

long-term price trends in the non-ferrous metal mining 

industry: Internat. Geol. Gong., 24th, Montreal, 1972, Proc. 

Sec. 4 Mineral deposits, p. 3-15.

Brobst, D. A., and Pratt, W. P., 1973, eds., United States mineral resources: U.S. Geol. Survey Prof. Paper 820, 722 p.

Calkins, J. A., Kays, Olaf, and Reefer, E. K., 1973, CRIB the 

mineral resources data bank of the U.S. Geological Survey: 

U.S. Geol. Survey Circ. 681, 39 p.

Council on International Economic Policy, 1974, Special Report Critical Imported Materials: Washington, D.C., 

U.S. Govt. Printing Office, 49 p.

Counselman, B. J., compiler, 1973, Annual report on Indian 

Lands: Department of the Interior, Bureau of Indian 

Affairs, 66 p.

Derry, D. R., 1973, Potential ore reserves an experimental 

approach: Western Miner, v. 46, no. 10, p. 115-122.

Harris, D. P., Freyman, A. J., and Barry, G. S., 1970, The 

methodology employed to estimate potential mineral supply 

of the Canadian Northwest an analysis based upon geologic opinion and systems simulation: Canada Dept. Energy, Mines and Resources, Mineral Resources Branch, 

Mineral Rept. MR-105, 56 p.

Henderson, B. C., 1974, Student enrollment rises somewhat: 

Geotimes, v. 19, no. 11, p. 20-21.

Hubbert, M. K., 1962, Energy resources: Natl. Acad. Sci. 

Natl. Research Council Pub. 1000-D, 141 p.

Hubbert, M. K., 1967, Degree of advancement of petroleum 

exploration in United States: Am. Assoc. Petroleum Geologists Bull., v. 51, no. 11, p. 2207-2227.

Hubbert, M. K., 1969, Energy resources, in Resources and 

Man: San Francisco, W. H. Freeman and Co., p. 157-242.

Lowell, J. D., 1970, Copper resources in 1970: Mining Eng., 

v. 22, no. 4, p. 67-73.

McKelvey, V. E., 1972, Mineral resource estimates and public 

policy: Am. Scientist, v. 60, no. 1, p. 32-40; reprinted in 

Brobst and Pratt, 1973, p. 9-19.

Meadows, D. H., Meadows, D. L., Randers, J0rgen, and 

Behrens, W. W., Ill, 1972, The limits to growth: New 

York, Universe Books, 205 p.

Mining and Minerals Policy, 1973, Report of the Secretary of 

the Interior under the Mining and Minerals Policy Act of 

1970 (P.L. 91-631), 2nd Ann.: Washington, B.C., U.S. 

Govt. Printing Office, 73 p. plus pt. 2 Appendices.

Mining Magazine, 1974, International mining survey: Mining 

Mag. v. 131, no. 3, p. 191-219.

Moore, C. L., 1966, Projections of U.S. petroleum supply to 

1980: Washington, D.C., U.S. Dept. Interior, Office of Oil 

and Gas, 13 p.

Moore, C. L., 1970, Analysis and projection of historic patterns 

of U.S. crude oil and natural gas, in Future petroleum 

provinces of the United States A summary: Washington, 

D.C., Natl. Petroleum Council, p. 133-138.

National Academy of Sciences, and National Research Council, 

1975, Mineral resources and the environment: Washington, 

D.C., Natl. Acad. Sci., 348 p.

Nolan, T. B., 1950, The search for new mining districts: Econ. 

Geology, v. 45, p. 601-608.

Pratt, W. P., and Brobst, D. A., 1974, Mineral resources 

potentials and problems: U.S. Geol. Survey Circ. 698, 20 p.

Rowan, L. C., and others, 1974, Discrimination of rock types 

and detection of hydrothermally altered areas in southcentral Nevada by the use of computer-enhanced ERTS 

images: U.S. Geol. Survey Prof. Paper 883, 35 p.

Slichter, L. B., Dixon, W. J., and Myer, G. H., 1962, Statistics 

as a guide to prospecting, in Computer short course and 

symposium on mathematical techniques and computer 

applications in mining and exploration: College of Mines, 

Univ. Arizona, p. F11-F27.

U.S. Bureau of Land Management, 1972, Public Land Statistics: Washington, D.C., U.S. Govt. Printing Office, 101 p.

U.S. Bureau of Mines, 1970, Mineral facts and problems: U.S. 

Bur. Mines Bull. 650, 1291 p.
24 MINERAL RESOURCE PERSPECTIVES 1975

U.S. Bureau of Mines, 1974a, Bureau of Mines research 1973 

A summary of significant results in mining, metallurgy, 

and energy: Washington, D.C., U.S. Govt. Printing Office, 

107 p.

U.S. Bureau of Mines, 1974b, Commodity data summaries 

1974 Appendix I to mining and minerals policy Third 

annual report of the Secretary of the Interior under the 

Mining and Minerals Policy Act of 1970: 193 p.

U.S. Bureau of Mines, and U.S. Geological Survey, 1947, 

Mineral position of the United States, Appendix to Hearings before a subcommittee of the Committee on Public

Lands, United States Senate, 80th Congress, first session, 

on investigation of the factors affecting minerals, fuels, 

forestry, and reclamation projects, May 15, 16, and 20, 

1947: Washington, D.C., U.S. Govt. Printing Office, p. 

167-338.

U.S. Geological Survey, 1975, Geological Survey Research 

1974: U.S. Geol. Survey Prof. Paper 900, 349 p.

U.S. National Commission on Materials Policy, 1973, Material 

needs and the environment today and tomorrow: Washington, D.C., U.S. Govt. Printing Office, variously paged.

*U S. GOVERNMENT PRINTING OFFICE- 1975 O 585 475/136