Au, U, Fe, Mn, Hg, Sb, W, and P Deposits, Volume 7

Chapter 1. Gold in the Proterozoic Sediments of South Africa: Systems, Paradigms, and Models

Introduction

Gold Mineralization in South Africa

South Africa's Place as a Mineral Producer

Geological Eras and Mineral Production

Gold in Time and Space

Systems, Paradigms, and Models

Paradigms of Sedimentary Gold

Model of a Source Area

Models of Transfer Systems

Models of Depositories

Stratigraphic Models

Model of a Transvaal-Type Goldfield

Model of a Witwatersrand-Type Goldfield

Models of Gold in Time

Tectonic Elevation Model

Algal Activity Model

Ground-Rules for Gold Prospecting

Note Added in Proof

References

Chapter 2. The Nature of the Witwatersrand Gold-Uranium Deposits

Introduction

The Economic Significance of the Witwatersrand Basin

The Witwatersrand Basin in Time and Space

Age of the Witwatersrand Strata

Proterozoic Basins and the Pattern of Crustal Evolution

The Architecture of the Witwatersrand Basin

Structure and Components

Pattern of Folding

Pattern of Faulting

Source of Wealth in the Witwatersrand Basin

Stratigraphy and Lithology

Succession and Thickness

Nature of Components

Dykes and Sills

Sedimentology

Depositional Isopachs

Fluvial Fans

Vertical Distribution of Mineralized Horizons

The Nature of the Mineralization

Production of Gold and Uranium

Types of Reefs

Composition of Conglomerates

Mineralogy of the Reefs

Chemistry of the Reefs

Relationships Between Components

Grain Size of Gold, Uranium, and Platinoids

The Characteristics of a Goldfield

Processes of Development

Final Responses to Processes

Sequential Development of Adjacent Fans

Progressive Development of a Goldfield

The Source of the Gold and Uranium

References

Chapter 3. Origin of Western-States Type Uranium Mineralization

Introduction

Tectonic Conditions

Sedimentation

Braided-Stream Fluvial System

Coarse-Grained Meanderbelt

Fine-Grained Meanderbelt

Sedimentary Environment, Paleoclimate and Diagenesis

Mineralization and Alteration

Geochemical-Cell Concept

Geochemical-Cell Reaction

Physical and Chemical Conditions

Character of Alteration

Mineral Zoning

Cell Growth and Shape

Modification of Geochemical-Cell Development

Time of Mineralization

Source of Mineralization

Genetic Model

Discussion

Topics for Future Research

Notes Added in Proof

References

Chapter 4. Origin of the Precambrian Banded Iron-Formations

Introduction

Terminology and Definition of Iron-Formation

Regional Geologic Distribution

Ages of Precambrian Banded Iron-Formations

Geologieal setting

Depositional Environments

Sedimentary Facies of Iron-Formations

Sedimentary Structures

Diagenetic and Metamorphic Alterations of the Mineral Phases

Organic Remains

Chemical Composition

Similarities and Differences Between Banded and Oolitic Iron-Formations

Hypotheses of Origin

Environments of Deposition

Source of Iron and Silica

Transport, Deposition and Banding

Conclusions

Acknowledgements

References

Chapter 5. Aspects of the Sedimentary Petrology of Cherty Iron-Formation

Introduction

Definition and General Description

Terminology

Sedimentary Features

Sedimentary Textures

Sedimentary Structures

Organo-Sedimentary Textures and Structures

Classification

Diagenesis

Syn-Sedimentary Deformation

Shrinkage (Syneresis) Features

Compaction

Concretionary Bodies

Solution and Solution-Collapse Features

Stylolites

Crystallization Textures

Quartz in Matrix Cherts

Quartz of Cement Chert

Iron-Minerals

Physico-Chemistry of Iron-Mineral Diagenesis

Paleogeographic Analysis

Lake Superior-Type I.Fs

Algoma-Type Iron-Formations

Special Problems of Iron-Formation Paleogeography

Depth-Control of Iron-Mineral Facies

Tectonic Control of Iron-Formation Deposition

Origin of Cherty Iron-Formations

Transport of Iron and Silica

Direct-Precipitation Hypotheses

Replacement Hypotheses

Summary and Conclusions

Acknowledgements

References

Chapter 6. Genetic Problems and Environmental Features of Volcano-Sedimentary Ironore Deposits of the Lahn-Dill Type

Introduction

General Diagnostic Statement

Geological Setting

Regional and Stratigraphic Distribution

Geotectonic and Paleogeographic Framework

Depositional Environment of the Volcano-Sedimentary Iron Ores

Sedimentary Facies of the Volcano-Sedimentary Iron Ores

Mineralogical Facies of the Volcano-Sedimentary Iron Ores

Chemical Composition of the Volcano-Sedimentary Iron Ores

The Origin of Volcano-Sedimentary Iron Ores

Hypotheses of Origin

Actualistic Examples of the Formation of Iron-Rich Sediments by Volcanic Processes

Similarities and Differences Between the Lahn-Dill Type and Other Types of Sedimentary Iron Formations

The Relation of Volcano-Sedimentary Iron Ores To Other Syngenetic Metal Mineralizations in Geosynclinal Environments

Possible Source of Iron and Silica in Ophiolitic Geosynclinal Volcanism

Conclusions

Acknowledgement

References

Chapter 7. Deep-Sea Manganese Nodules

Historical Introduction

Distribution of Manganese Nodules in the World's Oceans

Regional Distribution

Sedimentation Rate

Availability of Potential Nucleating Agents

Age

Bottom Current Velocity

Biological Activity

Redox Conditions

Localised Distribution

Distribution with Depth

Geochemistry

Compositional Variations Within Individual Nodules

Localised Variations in Composition

Regional Variations in Composition

Mineralogy

Internal Structure

Determination of Valency States

Rates and Mechanisms of Accretion Nodules

Thermochemical Considerations

Acknowledgements

References

Chapter 8. Freshwater Ferromanganese Deposits

Introduction

Geologic Setting

Occurrence and Morphology of Freshwater Ferromanganese Oxides

Coatings

Crusts

Nodules

Dispersed Ferromanganese Oxides

Sediment Types Associated with Ferromanganese Nodules

Chemical Composition of Freshwater Ferromanganese Oxides

Iron/Manganese Ratios

Major-Element Chemistry

Minor-Element Chemistry

Regional Variability in Nodule Composition

Mineralogy

Comparison Between Marine and Freshwater Nodules

Mobilization/Precipitation of Iron and Manganese in the Sedimentary Environment

Aqueous Geochemistry of Iron and Manganese

Transport of Iron and Manganese

Interaction Between Source Waters and Lake Waters

Deposition of Iron and Manganese Oxyhydroxides

Theories of Origin

Historical Development

Precipitation From Overlying Water

Diagenetic Remobilization

Ferromanganese Oxide Precipitation Mechanism(S)

Summary and Conclusions

References

Chapter 9. Ancient Manganese Deposits

Introduction

Nonvolcanogenic-Sedimentary Manganese Deposits

Manganese Deposits Associated with Terrigenous Formations

Manganese Deposits Associated with Carbonate Formation

Manganese Deposits Associated with Iron-Formation

Fossil Manganese and Iron-Manganese Nodules

Sedimentary Manganese Ores and Stromatolites

Volcanogenic-Sedimentary Manganese Deposits

Deposits of Olympic Peninsula Type

Deposits of Noda Tamagawa Type

Deposits of West African Type

Deposits of Langban Type

Deposits of Karadzhal Type

Summary and Conclusion

Acknowledgements

References

Chapter 10. The Strata-Bound Cinnabar-Stibnite-Scheelite Deposits (Discussed with Examples From the Mediterranean Region)

Introduction

Sardinia

Turkey

Conclusions

The Eastern Alps

Spain

Conclusions

References

Chapter 11. Sedimentary Phosphate Deposits

Introduction

Distribution of Phosphate Deposits

Types of Phosphate Deposits

"Geosynclinal" Phosphorites

"Platform" Phosphorites

Weathered and Residual Phosphorites

Petrology of Phosphorites

Phosphatic Nodules

Phosphatic Grains and Pellets

Non-Pelletal Phosphate

Geochemistry of Phosphorites

The Genesis of Phosphorites

Conclusions

References

References Index Part II

Subject Index Part II

Handbook of Strata-Bound and Stratiform Ore Deposits, Volume 7: Au, U, Fe, Mn, Hg, Sb, W, and P Deposits focuses on the characteristics, properties, origins, and structures of Au, U, Fe, Mn, Hg, Sb, W, and P deposits.

The selection first elaborates on gold in the Proterozoic sediments of South Africa, nature of the Witwatersrand gold-uranium deposits, and origin of Western-States type uranium mineralization. Discussions focus on tectonic conditions, sedimentation, mineralization and alteration, architecture of the Witwatersrand Basin, source of wealth in the Witwatersrand Basin, gold mineralization in South Africa, and ground-rules for gold prospecting. The text then ponders on origin of the Precambrian banded iron-formations, aspects of the sedimentary petrology of cherty iron-formation, and genetic problems and environmental features of volcanosedimentary iron-ore deposits of the Lahn-Dill Type. Concerns cover geological setting, crystallization structures, origin of cherty iron-formations, similarities and differences between banded and oolitic iron-formations, regional geologic distribution, and general diagnostic statement. The manuscript examines sedimentary phosphate deposits, ancient manganese deposits, and freshwater ferromanganese deposits.

The selection is a dependable reference for researchers wanting to explore Au, U, Fe, Mn, Hg, Sb, W, and P deposits.