Introduction to Ore-Forming Processes

A comprehensive account of ore-forming processes, revised and updated
 
The revised second edition of Introduction to Ore-Forming Processes offers a guide to the multiplicity of geological processes that result in the formation of mineral deposits. The second edition has been updated to reflect the most recent developments in the study of metallogeny and earth system science.
 
This second edition contains new information about global tectonic processes and crustal evolution that continues to influence the practice of economic geology and maintains the supply of natural resources in a responsible and sustainable way. The replenishment of depleted natural resources is becoming more difficult and environmentally challenging. There is also a change in the demand for mineral commodities and the concern around the non-sustainable supply of 'critical metals' is now an important consideration for planners of the future. The book puts the focus on the responsible custodianship of natural resources and the continuing need for all earth scientists to understand metallogeny and the resource cycle. This new edition:
* Provides an updated guide to the processes involved in the formation of mineral deposits
* Offers an overview of magmatic, hydrothermal and sedimentary ore-forming processes
* Covers the entire range of mineral deposit types, including the fossil fuels and supergene ores
* Relates metallogeny to global tectonics by examining the distribution of mineral deposits in space and time
* Contains examples of world famous ore deposits that help to provide context and relevance to the process-oriented descriptions of ore genesis
 
Written for students and professionals alike, Introduction to Ore-Forming Processes offers a revised second edition that puts the focus on the fact that mineral deposits are simply one of the many natural wonders of geological process and evolution.

List of contents

Preface to the 2nd Edition xiii
 
Preface to the 1st Edition xv
 
Introduction: Mineral Resources xvii
 
Part I Igneous Processes 1
 
1 Igneous Ore-Forming Processes 3
 
1.1 Introduction 4
 
1.2 Magmas and Metallogeny 4
 
1.2.1 Crustal Architecture and Mineral Wealth 4
 
1.2.2 Magma Types and Metal Contents 7
 
1.2.2.1 Basalt 7
 
1.2.2.2 Andesite 9
 
1.2.2.3 Rhyolite 10
 
1.2.2.4 Alkaline Magmas, Carbonatite and Kimberlite 12
 
1.3 Why Are Some Magmas More Fertile than Others? The "Inheritance Factor" 13
 
1.3.1 The "Late Veneer" Hypothesis of Siderophile Metal Concentration - An Extraterrestrial Origin for Au and Pt? 14
 
1.3.2 Diamonds and the Story They Tell 15
 
1.3.3 Metal Concentrations in Metasomatized Mantle and Their Transfer into the Crust 20
 
1.3.4 Metal Enrichment in Carbonatitic and Peralkaline Magmas 21
 
1.3.5 I- and S-Type Granite Magmas and Metal Specificity 27
 
1.4 Partial Melting and Crystal Fractionation as Ore-Forming Processes 30
 
1.4.1 Partial Melting 31
 
1.4.1.1 Trace Element Distribution During Partial Melting 32
 
1.4.2 Crystallization of Magma 34
 
1.4.2.1 The Form and Internal Zonation of Igneous Bodies 36
 
1.4.2.2 Trace Element Distribution During Fractional Crystallization 39
 
1.4.3 Fractional Crystallization and the Formation of Monomineralic Chromitite Layers 43
 
1.4.3.1 The Irvine Model 43
 
1.4.3.2 Other Mechanisms for the Formation of Chromitite Layers or Pods 47
 
1.4.4 Filter Pressing as a Process of Crystal Fractionation 48
 
1.4.4.1 Anorthosite Hosted Ti-Fe Deposits 48
 
1.5 Liquid Immiscibility as an Ore-Forming Process 49
 
1.5.1 Silicate-Oxide Immiscibility 49
 
1.5.2 Silicate-Sulfide Immiscibility 50
 
1.6 A More Detailed Consideration of Mineralization Processes in Mafic Magmas 52
 
1.6.1 A Closer Look at Sulfide Solubility 52
 
1.6.2 Sulfide-Silicate Partition Coefficients 53
 
1.6.3 The R Factor and Concentration of Low Abundance Trace Elements 54
 
1.6.4 Factors that Promote Sulfide Saturation 56
 
1.6.4.1 Addition of Externally Derived Sulfur 56
 
1.6.4.2 Fractional Crystallization 56
 
1.6.4.3 Injection of a New Magma and Magma Mixing 58
 
1.6.4.4 Magma Contamination 68
 
1.6.5 Other Models for Mineralization in Layered Mafic Intrusions 69
 
1.6.5.1 PGE Clusters 69
 
1.6.5.2 The Role of Chromite in PGE Concentration 71
 
1.6.5.3 Hiatus Models 72
 
1.6.5.4 Fluid-Related Infiltration of PGE 72
 
1.7 A Model for Mineralization in Layered Mafic Intrusions 72
 
1.8 Summary 75
 
Further Reading 75
 
2 Magmatic-Hydrothermal Ore-Forming Processes 77
 
2.1 Introduction 77
 
2.2 Some Physical and Chemical Properties of Water 78
 
2.3 Formation of a Magmatic Aqueous Phase 81
 
2.3.1 Magmatic Water - Where Does It Come from? 81
 
2.3.2 H2O Solubility in Silicate Magmas 83
 
2.3.3 The Burnham Model 85
 
2.3.3.1 A Note on the Mechanical Effects of Boiling 88
 
2.4 The Composition and Characteristics of Magmatic-Hydrothermal Solutions 88
 
2.4.1 Quartz Veins - What Do They Tell Us About Fluid Compositions? 88
 
2.4.2 Major Elements in Magmatic Aqueous Solutions 89
 
2.4.3 Other Important Components of Magmatic Aqueous Solutions 89
 
2.4.3.1 Magmatic Fluid Compositions from Fluid Inclusion Analysis 92
 
2.4.4 Carbon Dioxide in Magmatic Fluids 94
 
2.4.5 Other Important Features of Magmatic Fluids

About the author

LAURENCE ROBB is Visiting Professor in Economic Geology at the Department of Earth Sciences, University of Oxford. He continues to work on the metallogeny of the mineral districts of the African continent and also in SE Asia. He served a term as President of the Society of Economic Geologists in 2017.

Summary

A comprehensive account of ore-forming processes, revised and updated

The revised second edition of Introduction to Ore-Forming Processes offers a guide to the multiplicity of geological processes that result in the formation of mineral deposits. The second edition has been updated to reflect the most recent developments in the study of metallogeny and earth system science.

This second edition contains new information about global tectonic processes and crustal evolution that continues to influence the practice of economic geology and maintains the supply of natural resources in a responsible and sustainable way. The replenishment of depleted natural resources is becoming more difficult and environmentally challenging. There is also a change in the demand for mineral commodities and the concern around the non-sustainable supply of 'critical metals' is now an important consideration for planners of the future. The book puts the focus on the responsible custodianship of natural resources and the continuing need for all earth scientists to understand metallogeny and the resource cycle. This new edition:
* Provides an updated guide to the processes involved in the formation of mineral deposits
* Offers an overview of magmatic, hydrothermal and sedimentary ore-forming processes
* Covers the entire range of mineral deposit types, including the fossil fuels and supergene ores
* Relates metallogeny to global tectonics by examining the distribution of mineral deposits in space and time
* Contains examples of world famous ore deposits that help to provide context and relevance to the process-oriented descriptions of ore genesis

Written for students and professionals alike, Introduction to Ore-Forming Processes offers a revised second edition that puts the focus on the fact that mineral deposits are simply one of the many natural wonders of geological process and evolution.

Product details

• Authors: L Robb, Laurence Robb, Laurence (University of Witwatersrand) Robb
• Publisher: Wiley, John and Sons Ltd
• Languages: English
• Product format: Paperback / Softback
• Released: 15.10.2020
• EAN: 9781119967507
• ISBN: 978-1-119-96750-7
• No. of pages: 496
• Dimensions: 178 mm x 253 mm x 20 mm
• Subjects: Education and learning > Teaching preparation > Vocational needs; Natural sciences, medicine, IT, technology > Geosciences > Geology; Geowissenschaften, Umweltwissenschaften, NATURE / Natural Resources, Nature, SCIENCE / Earth Sciences / Geology, Earth Sciences, Strukturgeologie, Structural Geology & Tectonics, Strukturgeologie, Tektonik, Economic & Applied Geology, Angewandte u. ökonomische Geologie