The Economic Aspect of Geology
In adapting ourselves to physical environment it has been necessary to learn something about the earth. Mainly within the last century has this knowledge been organized into the science of geology, and only within the last few decades have the complex and increasing demands of modern civilization required the applications of geology to practical uses, resulting in the development of the science generally known as economic geology . This science is not sharply marked off from the science of geology proper; almost any phase of geology may at some time or some place take on its economic aspect.
The usefulness of economic geology was first recognized in relation to mineral resources,—and particularly in relation to metallic resources, their discovery and development,—but the science has been found to have much wider practical application. The practice of the economic geologist in recent years has taken on many new phases.
The geologist is called upon to study the geologic features of mineral deposits, their occurrence, structure, and origin. The basic information thus acquired is useful in estimating reserves and life of mineral deposits. This leads naturally to considerations of valuation. Because valuation plays such a large part in any tax program, the geologist is being used by tax boards of the federal and state governments.
Both in the formulation of laws relating to mineral resources, and in the litigation growing out of the infraction of these laws, the economic geologist plays a part.
One cannot go very far with the study of mineral resources without consideration of the question of conservation. Geologists are called on not only for broad surveys of the mineral reserves, but for the formulation of general principles of conservation and their application to specific mines and minerals.
C. K. Leith
THE ECONOMIC ASPECTS OF GEOLOGY
C. K. LEITH
UNIVERSITY OF WISCONSIN
CONTENTS
ILLUSTRATIONS
SURVEY OF FIELD
ECONOMIC APPLICATIONS OF THE SEVERAL BRANCHES OF GEOLOGY AND OF OTHER SCIENCES
Mineralogy and Petrology
Rock Alterations or Metamorphism
Application of Other Sciences
TREATMENT OF THE SUBJECT IN THIS VOLUME
RELATIVE ABUNDANCE OF THE PRINCIPAL ELEMENTS OF THE LITHOSPHERE
RELATIVE ABUNDANCE OF THE PRINCIPAL ROCKS OF THE LITHOSPHERE
Water (Hydrosphere)
COMPARISON OF LISTS OF MOST ABUNDANT ROCKS AND MINERALS WITH COMMERCIAL ROCKS AND MINERALS
THE ORIGIN OF COMMON ROCKS AND MINERALS
Weathering of Igneous Rocks and Veins
Sedimentary Processes
Weathering of Sedimentary Rocks
Consolidation, Cementation, and Other Subsurface Alterations of Rocks.
THE METAMORPHIC CYCLE AS AN AID IN STUDYING MINERAL DEPOSITS
VARIOUS METHODS OF CLASSIFICATION
NAMES
MINERAL DEPOSITS AS MAGMATIC SEGREGATIONS IN IGNEOUS ROCKS
Evidence of Igneous Source
Possible Influence of Meteoric Waters in Deposition of Ores of This Class
Zonal Arrangement of Minerals Related to Igneous Rocks
The Relation of Contact Metamorphism to Ore Bodies of the Foregoing Class.
SECONDARY CONCENTRATION IN PLACE OF THE FOREGOING CLASSES OF MINERAL DEPOSITS THROUGH THE AGENCY OF SURFACE SOLUTIONS
RESIDUAL MINERAL DEPOSITS FORMED BY THE WEATHERING OF IGNEOUS ROCKS IN PLACE
Mechanically Deposited Minerals
Chemically and Organically Deposited Minerals
ANAMORPHISM OF MINERAL DEPOSITS
CONCLUSION
WORLD ANNUAL PRODUCTION OF MINERALS IN SHORT TONS
SIGNIFICANCE OF GEOGRAPHIC DISTRIBUTION OF MINERAL PRODUCTION
THE INCREASING RATE OF PRODUCTION
CAPITAL VALUE OF WORLD MINERAL RESERVES
RESERVES OF MINERAL RESOURCES
GENERAL GEOLOGIC RELATIONS
DISTRIBUTION OF UNDERGROUND WATER
Approximate Quantity of Water which will be Absorbed by Soils and Rocks1
WELLS AND SPRINGS
COMPOSITION OF UNDERGROUND WATERS
RELATION OF GEOLOGY TO UNDERGROUND WATER SUPPLY
SURFACE WATER SUPPLIES
UNDERGROUND AND SURFACE WATERS IN RELATION TO EXCAVATION AND CONSTRUCTION
ECONOMIC FEATURES OF THE COMMON ROCKS
Basalt and Related Types
Limestone, Marl, Chalk
Marble
"Sand and Gravel"
Clay, Shale, Slate
Hydraulic Cement (including Portland, natural, and Puzzolan cements)
GEOLOGIC FEATURES OF THE COMMON ROCKS
Building Stone
Crushed Stone
Stone for Metallurgical Purposes
Clay
Limitations of Geologic Field in Commercial Investigation Of Common Rocks
SOILS AS A MINERAL RESOURCE
Origin of Soils
Composition of Soils and Plant Growth
Use of Geology in Soil Study
GENERAL COMMENTS
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
OIL SHALES
Geologic Features
GENERAL FEATURES
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Geologic Features
Partly Explored Versus Virgin Territories
The Use of All Available Information
Economic Factors in Exploration
Geologic Factors in Exploration
Mineral Provinces and Epochs
Classification of Mineral Lands
Outcrops of Mineral Deposits
Some Illustrative Cases
Size and Depth of Ore Bodies As Determined From Outcrop
The Use of Placers in Tracing Mineral Outcrops
The Use of Magnetic Surveys in Tracing Mineral Ledges
The Use of Structure and Metamorphism in Exploration
Drilling in Exploration
Quantitative Aspects of Geologic Exploration
Origin of Mineral Deposits As a Factor in Exploration
Lake Superior Iron Ore Exploration As an Illustration
Development and Exploitation of Mineral Deposits
POPULAR CONCEPTION OF MINERAL VALUATION
The Ad Valorem Method of Valuation
Other Methods of Mineral Valuation and Taxation
GENERAL COMMENTS ON TAXATION OF MINERAL RESOURCES
On the Public Domain
Nationalization of Mineral Resources
Effect of Ownership Laws on Exploration
Use of Geology in Relation To Ownership Laws
THE PROBLEM
DIFFERENCES BETWEEN PRIVATE AND PUBLIC EFFORTS IN CONSERVATION
CONSERVATION OF COAL
Measures Introduced or Proposed to Conserve Coal
Division of Responsibility Between Government and Private Interests in the Conservation of Coal
CONSERVATION OF MINERALS OTHER THAN COAL
WORLD MOVEMENT OF MINERALS
Movement of Minerals Under Pre-war Conditions of International Trade
Changes During the War
Post-war Condition of the Mineral Trade
Methods of International Coöperation
CONSERVATION IN ITS INTERNATIONAL RELATIONS
EXPLORATION IN ITS INTERNATIONAL RELATIONS
VALUATION IN ITS INTERNATIONAL RELATIONS
RELATIVE POSITION OF THE UNITED STATES IN REGARD TO SUPPLIES OF MINERALS
THE COAL AND IRON SITUATION OF WESTERN EUROPE UNDER THE TERMS OF THE PEACE TREATY
CONCLUSION
LITERATURE
GEOLOGY BEHIND THE FRONT
EFFECT OF THE WAR ON THE SCIENCE OF ECONOMIC GEOLOGY
FOUNDATIONS
TUNNELS
SLIDES
SUBSIDENCE
RAILWAY BUILDING
ROAD BUILDING
PURE VERSUS APPLIED SCIENCE
COURSE OF STUDY SUGGESTED
Field Work
Specialization in Studies
A Degree of Economic Geology
THE OPPORTUNITIES OF THE ECONOMIC GEOLOGIST
ETHICS OF THE ECONOMIC GEOLOGIST
INDEX