Petrology of Lamproites

1. The Lamproite Clan-Etymology and Historical Perspective.- 1.1. Introduction.- 1.2. Initial Discoveries-1870-1906.- 1.3. Etymology of Lamproite.- 1.4. Western Australian Discoveries-The Legitimization of Lamproites.- 1.5. Johannsen and Modal Classifications of Rocks.- 1.6. Further Developments, New Occurrences, and Diamond-Bearing Lamproites.- 1.7. Reclassification of Anomalous Kimberlites.- 1.8. Recent Developments.- 2. Potassic Rocks and the Lamproite Clan.- 2.1. Alkalinity, Sodic, Potassic, and Ultrapotassic Rocks.- 2.2. Alkali-Alumina Relationships.- 2.3. Potassic Rocks-General Petrographie Characteristics and Terminology.- 2.3.1. Lamproites.- 2.3.2. Roman Province Leucitites.- 2.3.3. Ultrapotassic Leucitites.- 2.3.4. Kalsilite-Bearing Lavas (Kamafugitic Rocks).- 2.3.5. Potassic Lamprophyres.- 2.3.6. Kimberlite and Micaceous Kimberlites.- 2.3.7. The Shoshonite Association.- 2.3.8. Potassic Intrusive Rocks.- 2.4. Petrochemical Classifications of Potassic Rocks.- 2.4.1. Niggli Parameters.- 2.4.2. K2O-Na2O Diagrams.- 2.4.3. Total Alkali-Silica Classifications.- 2.4.4. Sahama (1974).- 2.4.5. Barton (1979).- 2.4.6. Bogatikov et al. (1985).- 2.4.7. Foley et al. (1987).- 2.5. Petrographie and Mineralogical Classifications.- 2.5.1. Petrographie Classifications.- 2.5.2. Mineralogical Classifications.- 2.6. The Lamproite Clan.- 2.6.1. Geochemical Criteria for Lamproite Recognition.- 2.6.2. Mineralogical Criteria for Lamproite Recognition.- 3. Description of Lamproite Occurrences-Distribution, Age, Characteristics, and Geological Framework.- 3.1. Introduction.- 3.2. North American and Greenland Lamproites.- 3.2.1. Group Name: Prairie Creek.- 3.2.2. Group Name: Leucite Hills.- 3.2.3. Group Name: Smoky Butte.- 3.2.4. Group Name: Francis.- 3.2.5. Group Name: Hills Pond.- 3.2.6. Group Name: Sisimiut.- 3.2.7. Group Name: Yellow Water Butte.- 3.2.8. Group Name: Froze-to-Death Butte.- 3.3. European Lamproites.- 3.3.1. Group Name: Murcia-Almeria.- 3.3.2. Group Name: Sisco.- 3.3.3. Group Name: Sesia-Lanzo and Combin.- 3.4. African Lamproites.- 3.4.1. Group Name: Kapamba.- 3.4.2. Group Name: Pneil, Postmasburg, Swartruggens.- 3.4.3. Group Name: Bobi.- 3.5. Australian Lamproites.- 3.5.1. Group Name: Argyle.- 3.5.2. Group Name: West Kimberley.- 3.6. Antarctic Lamproites.- 3.6.1. Group Name: Gaussberg.- 3.6.2. Group Names: Mount Bayliss and Priestley Peak.- 3.7. Asian Lamproites.- 3.7.1. Group Name: Chelima.- 3.7.2. Group Name: Majhgawan.- 3.7.3. Group Name: Barakar.- 3.7.4. Group Name: Murun.- 3.8. South American Lamproites.- 3.8.1. Group Name: Coromandel.- 3.9. Conclusions.- 4. Tectonic Framework of Lamproite Genesis.- 4.1. Age and Temporal Relations of Lamproite Magmatism.- 4.2. Regional Geological and Tectonic Setting Generalizations.- 4.2.1. Lamproites and Plate Tectonics.- 4.2.2. Lamproites and Contemporaneous Subduction Zones.- 4.2.3. Fracture Zones, Transform Faults, and Continental Lineaments.- 4.2.4. Mantle Plumes, Hot Spots, and Hot Regions.- 4.2.5. Continental Rift Zones and Aulacogens.- 4.2.6. Orogeny and Postorogenic Relaxation.- 4.3. Lithospheric History of Lamproite Settings.- 4.3.1. Regional Structure.- 4.3.2. Basement Age, Composition, and Evolution.- 4.3.3. Contemporaneous, Previous, and Subsequent Magmatism.- 4.3.4. Importance of Paleosubduction and Fossil Benioff Zones.- 4.3.5. Mantle Metasomatism-Another Necessary Condition.- 4.3.6. Comparison with Kimberlites, Alkali Basalts, Lamprophyres, and Potassium-Rich Rocks.- 4.4. Tectonic Framework of Four Mesozoic-to-Cenozoic Lamproite Type-Locality Magmatic Fields.- 4.4.1. Leucite Hills.- 4.4.2. West Kimberley.- 4.4.3. Murcia-Almeria.- 4.4.4. Prairie Creek.- 4.5. Conclusions and Preferred Model.- 5. Petrological Facies and Igneous Forms of the Lamproite Clan.- 5.1. Introduction.- 5.1.1. Historical Development.- 5.1.2. Lamproite Igneous Forms.- 5.1.3. Lamproite Facies Classification.- 5.2. Lava Flow Facies.- 5.2.1. Examples of Lava Flow Facies Lamproites.- 5.2.2. Comparisons with Other Mafic and Intermediate Lavas.- 5.2.3. Summary.- 5.3. Crater and Pyroclastic Facies.- 5.3.1. Vent Morphology.- 5.3.2. Pyroclastic Fall Deposits.- 5.3.3. Base Surge and Pyroclastic Flow Deposits.- 5.3.4. Epiclastic Deposits.- 5.3.5. Examples of Crater and Pyroclastic Facies Lamproites.- 5.4. Hypabyssal Facies.- 5.4.1. Examples of Hypabyssal Facies Lamproites.- 5.5. Plutonic Facies.- 5.6. Generalized Model of Eruptive Sequences.- 5.7. Comparison with Kimberlite Diatremes.- 5.8. Summary.- 6. Mineralogy of Lamproites.- 6.1. Phlogopite.- 6.1.1. Paragenesis.- 6.1.2. Leucite Hills, Wyoming.- 6.1.3. West Kimberley, West Australia.- 6.1.4. Argyle, West Australia.- 6.1.5. Prairie Creek, Arkansas.- 6.1.6. Murcia-Almeria, Spain.- 6.1.7. Smoky Butte, Montana.- 6.1.8. Kapamba, Zambia.- 6.1.9. Sisimiut, Greenland.- 6.1.10. Hills Pond-Rose Dome, Kansas.- 6.1.11. Bobi, Ivory Coast.- 6.1.12. Francis, Utah.- 6.1.13. Yellow Water Butte, Montana.- 6.1.14. Sisco, Corsica.- 6.1.15. Majhgawan, India.- 6.1.16. Gaussberg, Antarctica.- 6.1.17. Probable Lamproites-Murun, Presidente Oligario, and Chelima.- 6.1.18. Minor and Trace Elements.- 6.1.19. Summary of Mica Compositional Variations.- 6.1.20. Solid Solutions in Lamproite Mica.- 6.1.21. Comparisons with Mica in Other Potassic Rocks.- 6.1.22. Conditions of Crystallization.- 6.2. Amphibole.- 6.2.1. Classification.- 6.2.2. Paragenesis.- 6.2.3. Composition.- 6.2.4. Minor and Trace Elements.- 6.2.5. Comparisons with Amphiboles in Other Potassic Rocks.- 6.2.6. Conditions of Crystallization.- 6.3. Clinopyroxene.- 6.3.1. Paragenesis.- 6.3.2. Composition of Phenocrystal and Groundmass Pryoxenes.- 6.3.3. Compositions of Pyroxenes from Parageneses 2 and 3.- 6.3.4. Comparison with Pyroxenes in Other Potassic Rocks.- 6.4. Orthopyroxene.- 6.4.1. Paragenesis.- 6.4.2. Composition.- 6.5. Olivine.- 6.5.1. Paragenesis.- 6.5.2. Composition.- 6.5.3. Summary.- 6.6. Leucite.- 6.6.1. Paragenesis.- 6.6.2. Composition.- 6.7. Analcite.- 6.8. Sanidine.- 6.8.1. Paragenesis.- 6.8.2. Composition.- 6.9. Spinel.- 6.9.1. Paragenesis-Primary Spinels.- 6.9.2. Composition-Primary Spinels.- 6.9.3. Comparison with Primary Spinels from Kimberlite and Lamprophyre.- 6.9.4. Secondary Aluminous Spinels.- 6.10. Priderite.- 6.10.1. Paragenesis.- 6.10.2. Composition.- 6.10.3. Ba-Titanates Related to Priderite.- 6.10.4. Comparison with Hollandites in Other Potassic Rocks.- 6.11. Jeppeite.- 6.12. Iron Titanium Oxides.- 6.12.1. Armalcolite.- 6.12.2. Ilmenite.- 6.12.3. Titanium Dioxides.- 6.13. Potassium Zirconium Silicates.- 6.13.1. Wadeite.- 6.13.2. Dalyite.- 6.14. Apatite.- 6.14.1. Paragenesis.- 6.14.2. Composition.- 6.15. Perovskite.- 6.15.1. Paragenesis.- 6.15.2. Composition.- 6.16. Titanosilicates.- 6.16.1. Shcherbakovite.- 6.16.2. Davanite.- 6.16.3. Unnamed K-Ba-Titanosilicate.- 6.17. Minor Accessory and Secondary Minerals.- 6.17.1. Zeolites.- 6.17.2. Carbonates.- 6.17.3. Roedderitelike Phases.- 6.17.4. Cerium-Bearing Minerals.- 6.17.5. Silicon Dioxide.- 6.17.6. Barite.- 6.17.7. Other Minerals.- 6.17.8. Secondary Phases.- 7. The Geochemistry of Lamproites.- 7.1. Major Element Geochemistry.- 7.1.1. General Characteristics.- 7.1.2. Compositional Relationships to Other Potassic Lavas.- 7.1.3. Intraprovincial Characteristics.- 7.2. Compatible Trace Elements.- 7.2.1. First Period Transition Elements.- 7.2.2. Platinum Group Elements.- 7.3. Incompatible Trace Elements-1: Ba?Sr, Zr?Hf, Nb?Ta, Th?U.- 7.3.1. Barium and Strontium.- 7.3.2. Zirconium and Hafnium.- 7.3.3. Niobium and Tantalum.- 7.3.4. Thorium and Uranium.- 7.4. Incompatible Trace Elements-2: Rare Earth Elements and Yttrium.- 7.4.1. Rare Earth Elements.- 7.4.2. Yttrium.- 7.5. Incompatible Trace Elements-3: Alkali Elements.- 7.5.1. Lithium.- 7.5.2. Rubidium.- 7.5.3. Cesium.- 7.6. Volatile Trace Elements: Fluorine, Sulfur, and Chlorine.- 7.7. Other Trace Elements.- 7.8. Interelement Relationships.- 7.9. Isotopic Composition.- 7.9.1. Strontium and Neodymium.- 7.9.2. Lead.- 7.9.3. Oxygen.- 7.10. Summary.- 8. Experimental Studies Relevant to the Formation and Crystallization of Lamproites.- 8.1. Low-Pressure Studies of Lamproites.- 8.1.1. Anhydrous Melting Relationships.- 8.1.2. Water-Saturated Melting Relationships.- 8.2. High-Pressure Phase Relationships of Natural Lamproites.- 8.2.1. Phlogopite Lamproites.- 8.2.2. Olivine and Madupitic Lamproites.- 8.3. Synthetic Systems.- 8.4. The Oxidation State of Lamproite Magmas.- 8.5. Summary.- 9. Diamonds, Xenoliths, and Exploration Techniques.- 9.1. Diamonds and Xenoliths: Alien, Yet Beneficial, Companions of Lamproites.- 9.2. Diamonds.- 9.2.1. Type, Morphology, Color, and Size.- 9.2.2. Mineral Inclusion Suite.- 9.2.3. Isotopic Composition.- 9.2.4. Comparison with Kimberlite Diamonds.- 9.2.5. Discussion.- 9.3. Xenoliths and Xenocrysts.- 9.3.1. Xenoliths in Olivine Lamproites.- 9.3.2. Xenoliths in Leucite and Phlogopite Lamproites.- 9.3.3. Discussion.- 9.4. Exploration Techniques for Diamondiferous Lamproite.- 9.4.1. Remote Sensing Techniques.- 9.4.2. Geophysical Techniques.- 9.4.3. Geochemical Surveys.- 9.4.4. Indicator/Heavy Mineral Sampling.- 9.4.5. Summary.- 10. Petrogenesis of Lamproites.- 10.1. Introduction.- 10.2. Previous Petrogenetic Models.- 10.2.1. Fractionation of Peridotite and Kimberlite.- 10.2.2. Contamination of Kimberlite.- 10.2.3. Partial Melting of Garnet Lherzolite.- 10.2.4. Incongruent Melting of Phlogopite.- 10.2.5. Fractional Fusion and Diapiric Uprise.- 10.2.6. Partial Melting of Enriched Mantle.- 10.2.7. Partial Melting of Harzburgitic Sources.- 10.2.8. Subduction-Related Models.- 10.3. Genesis of the Lamproite Clan.- 10.3.1. Character of the Source.- 10.3.2. Melting of the Source.- 10.3.3. Relationships between Olivine and Phlogopite Lamproites and the Origins of the Isotopic Signatures of the West Kimberley Lamproites.- 10.3.4. Relationship of Madupitic Lamproites to Phlogopite Lamproites and the Origins of Isotopic Signatures of the Leucite Hills Lamproites.- 10.3.5. The Anomalous Murcia-Almeria Lamproites.- 10.4. Relationships to Kimberlites.- 10.5. Relationships to MARID-Suite Xenoliths.- 10.6. Relationships to Other Potassic Rocks and Lamprophyres.- 10.7. Summary.- Postscript.- References.