Potassic Igneous Rocks and Associated Gold-Copper Mineralization

1 Introduction.- 1.1 Preamble: Potassic Igneous Rocks and Their Importance.- 1.2 Scope of Book.- 2 Definitions and Nomenclature.- 2.1 Historical Perspective of Potassic Igneous Rocks.- 2.2 Potassic Igneous Rocks as an Umbrella Term.- 2.3 Shoshonites.- 2.4 Shoshonitic and Alkaline Lamprophyres.- 2.5 Ultrapotassic Rocks.- 2.6 Group II Kimberlites.- 2.7 Potassic Igneous Rocks as Considered in this Book.- 2.8 Field Recognition of Potassic Igneous Rocks.- 3 Tectonic Settings of Potassic Igneous Rocks.- 3.1 Introduction.- 3.2 Tectonic Settings of Potassic Igneous Rocks.- 3.3 History of Discrimination of Tectonic Setting by Geochemical Means.- 3.4 Erection of Databases SHOSH1 and SHOSH2.- 3.5 Discrimination of Tectonic Setting by Multivariate Statistical Methods.- 3.6 Discrimination via Simple Geochemical Diagrams.- 3.7 Theoretical Basis for Discrimination Between Potassic Igneous Rocks in Different Tectonic Settings.- 3.8 Conclusions.- 4 Selected Type-Localities of Potassic Igneous Rocks from the Five Tectonic Settings.- 4.1 Roman Province (Italy): Example from a Continental Arc Setting.- 4.2 Kreuzeck Mountains, Eastern Alps (Austria): Example from a Postcollisional Arc Setting.- 4.3 Northern Mariana Arc (West Pacific): Example from an Initial Oceanic Arc Setting.- 4.4 Vanuatu (Southwest Pacific): Example from a Late Oceanic Arc Setting.- 4.5 African Rift Valley (Rwanda, Uganda, Zaire): Example from a Within-Plate Setting.- 5 Primary Enrichment of Precious Metals in Potassic Igneous Rocks.- 5.1 Introduction.- 5.2 Theoretical Discussion.- 5.3 Case Study: Potassic Alkaline Lamprophyres with Elevated Gold Concentrations from the Karinya Syncline, South Australia.- 5.4 Comparison of Precious Metal Abundances for Lamprophyres from the Karinya Syncline and Kreuzeck Mountains.- 6 Direct Associations Between Potassic Igneous Rocks and Gold-Copper Deposits.- 6.1 Direct Associations in Specific Tectonic Settings: Introduction.- 6.2 Erection of Database GOLD 1.- 6.3 Late Oceanic Arc Associations.- 6.4 Continental Arc Associations.- 6.5 Postcollisional Arc Associations.- 6.6 Synthesis of Direct Genetic Associations.- 7 Indirect Associations Between Lamprophyres and Gold-Copper Deposits.- 7.1 Introduction.- 7.2 Shoshonitic Lamprophyres with Elevated Gold Concentrations from the Goodall Gold Deposit, Northern Territory, Australia (Proterozoic).- 7.3 Shoshonitic Lamprophyres from the Tom's Gully Gold Deposit, Northern Territory, Australia (Proterozoic).- 7.4 Shoshonitic Lamprophyres from the Eastern Goldfields, Yilgarn Block, Western Australia (Archaean).- 7.5 Shoshonitic Lamprophyres from the Superior Province, Canada (Archaean).- 7.6 Indirect Link Between Lamprophyres and Archaean Gold Mineralization.- 7.7 Synthesis of Indirect Associations.- 8 Halogen Contents of Mineralized Versus Unmineralized Potassic Igneous Rocks.- 8.1 Introduction.- 8.2 Erection of Database MICA1.- 8.3 Discussion.- 9 Implications for Mineral Exploration.- 9.1 Introduction.- 9.2 Area Selection.- 9.3 Prospect Evaluation.- 10 Characteristics of Some Gold-Copper Deposits Associated with Potassic Igneous Rocks.- 10.1 Abbreviations.- 10.2 Tables of Deposit Characteristics.- References.