Kimberlites I: Kimberlites and Related Rocks: Proceedings of the Third International Kimberlite Conference , Volume-I

Developments in Petrology 11A, Volume A: Kimberlites I: Kimberlites and Related Rocks covers the proceedings of the Third International Kimberlite Conference, held in Clermont Ferrand, France in September 1982. Separating 75 papers into three parts and 28 chapters, this volume focuses on Western Australian lamproites and kimberlites. Significant chapters are also devoted to Alpine type ultramafic bodies. The occurrence, detection, geology, petrology, and synthesis of these precious rocks are discussed. Other general topics covered include diatremes, diamonds, and mantle sample. Front Cover Kimberlites: I: Kimberlites and Related Rocks Copyright Page Preface Table of Contents Acknowledgements List of Cotributors Academician Vladimir Stepanovitch Sobolev, Part I: Detection of Kimberlitic Occurrences Chapter 1. A Teledetective study of kimberlite regions in North America (Colorado-Wyoming), East Africa (Mwadui), and Siberia ( Mir ) 1. INTRODUCTION 2. PROCEDURE 3. STUDY AREAS 4. DISCUSSION 5. CONCLUSIONS ACKNOWLEDGMENTS Chapter 2. Evaluation of Geophysical Techniques for diatreme delineation in the Colorado-Wyoming Kimberlite Province INTRODUCTION GRAVITY SURVEYS MAGNETIC SURVEYS ELECTRICAL RESISTIVITY SURVEYS ELECTROMAGNETIC SURVEYS GAMMA RAY SPECTROMETRY SEISMIC REFRACTION SURVEYS CONCLUSIONS ACKNOWLEDGMENTS Chapter 3. Geobotanical expression of a blind kimberlite pipe, Central India 1. INTRODUCTION 2. HINOTA PIPE, CENTRAL INDIA 3. GEOBOTANICAL STUDIES 4. DISCUSSION 5. CONCLUDING REMARKS Part II: Natural Occurrences of Kimberlites And Related Rocks: Geology, Petrology, Mineralogy and Geochemistry Chapter 4. The Geology of the Mayeng Kimberlite sill complex, South Africa 1. INTRODUCTION 2. GEOLOGY AND SETTING OF THE MAYENG COMPLEX 3. PETROGRAPHY 4. BULK-ROCK GEOCHEMISTRY 5. MINERAL CHEMISTRY 6. DISCUSSION AND CONCLUSIONS 7. ACKNOWLEDGEMENT S Chapter 5. The oxide minerals of the Wesselton Mine Kimberlite, Kimberley, South Africa 1. INTRODUCTION 2. LOCATION AND PETROGRAPHY 3. METHODS OF STUDY 4. OXIDE MINERALOGY AND COMPOSITIONS 5. DISCUSSION AND CONCLUSIONS Chapter 6. Petrology of carbonate tuff from Melkfontein, East Griqualand, Southern Africa 1. INTRODUCTION 2. PETROGRAPHY AND MINERAL CHEMISTRY 3. DISCUSSION 4. CONCLUSIONS 5. ACKNOWLEDGMENTS Chapter 7. The Koidu Kimberlite Complex, Sierra Leone: Geological Setting, Petrology and Mineral chemistry ABSTRACT INTRODUCTION KIMBERLITE PETROGRAPHY NODULES PETROLOGY AND MINERAL CHEMISTRY GEOTHERMOMETRY - GEOBAROMETRY DISCUSSION ACKNOWLEDGMENTS Chapter 8. Petrography, Geochemistry and Strontium isotopic composition of the Mbuji-Mayi and Kundelungu Kimberlites (Zaire) 1. INTRODUCTION 2. ANALYTICAL METHODS 3. PETROGRAPHY 4. MAJOR ELEMENT COMPOSITION 5. STRONTIUM ISOTOPIC COMPOSITION 6. TRACE ELEMENT GEOCHEMISTRY 7. SUMMARY AND CONCLUSIONS Chapter 9. Kimberlites near Orroroo, South Australia 1. INTRODUCTION 2. AGE 3. PETROGRAPHY 4. KIMBERLITE MATRIX MINERAL CHEMISTRY 5. HEAVY MINERAL CONCENTRATES AND MINERAL CHEMISTRY 6. DIAMONDS 7. DIAMOND INCLUSION MINERALOGY AND CHEMISTRY 8. WHOLE-ROCK GEOCHEMISTRY 9. RELATED INTRUSIVES 10. DISCUSSION 11. CONCLUSIONS 12. ACKNOWLEDGMENTS Chapter 10. The Lake Ellen Kimberlite, Michigan, U.S.A. INTRODUCTION MEGACRYST-XENOCRYST SUITE LITHIC INCLUSIONS TEMPERATURE AND PRESSURE CONSIDERATIONS CONCLUSIONS ACKNOWLEDGEMENTS Chapter 11. Petrology of Megacrysts, mafic and ultramafic xenoliths from the Pipe of Eglazines, Causses, France I. INTRODUCTION II. THE BASALT, DESCRIPTION, CRYSTALLIZATION CONDITIONS Ill. PYROXENE MEGACRYSTS IV. PYROXENITES V. PERIDOTITES XENOLITHS VI. CONCLUSION Chapter 12. Oceanic carbonatites 1. INTRODUCTION 2. PETR0L0GICAL CHARACTERISTICS 3. GEOCHEMISTRY 4. FENITIZATION 5. CARBONATES ACKNOWLEDGMENTS Part III: Kimberlites and Lamproites: General Syntheses Chapter 13. Kimberlites in China and their major components: a discussion on the physico-chemical properties of the upper mantle 1. KIMBERLITES AND THEIR GEOLOGIC BACKGROUND 2. MINERALOGY OF THE KIMBERLITES 3. STRUCTURE AND TEXTURE OF KIMBERLITIC ROCKS AND THEIR MINERALS 4. CHEMICAL COMPOSITION OF KIMBERLITES 5. ISOTOPE AGE OF KIMBERLITES 6. PROPOSED MODELS FOR THE ASCENT OF KIMBERLITIC MAGMA 7. THE PHYSICO-CHEMICAL PROPERTIES OF THE UPPER MANTLE 8 SUMMARY Chapter 14. A review of the kimberlitic rocks of western Australia 1. INTRODUCTION 2. EXPLORATION METHODS AND RESULTS 3. STRUCTURAL SETTING 4. GEOLOGY OF OCCURRENCES 5. PETROGRAPHY AND MINERALOGY 6. GEOCHEMISTRY 7. DISCUSSIONS AND CONCLUSIONS 8. ACKNOWLEDGEMENTS Chapter 15. The Diamond-bearing ultrapotassic (lamproitic) rocks of the West Kimberley region, Western Australia INTRODUCTION DISTRIBUTION AND AGE GEOLOGY OF THE INTRUSIONS DEFINITION AND CLASSIFICATION OF LAMPROITE PETROGRAPHY MINERAL CHEMISTRY GEOCHEMISTRY PETROGENESIS LAMPROITES, KIMBERLITES AND DIAMONDS ACKNOWLEDGEMENTS Chapter 16. A New Look at Prairie Creek, Arkansas 1 INTRODUCTION 2 PETROGRAPHY 3 MINERAL CHEMISTRY 4 WHOLE ROCK GEOCHEMISTRY 5 DISCUSSION 6 CONCLUSIONS 7 ACKNOWLEDGEMENTS Chapter 17. Spanish and Western Australian lamproites: aspects of whole rock geochemistry 1 . INTRODUCTION 2. PETROGRAPHIC SUMMARY 3. CHEMICAL COMPOSITION 4. RARE EARTH ELEMENTS 5. ISOTOPE DATA AND CONCLUSIONS Part IV: Kimberlites: Physical and Chemical Processes Chapter 18. Explosive volcanism of the West Eifel volcanic field/Germany INTRODUCTION THE WEST EIFEL MAARS VOLCANIC SYSTEMS SCORIA CONES WITH INITIAL MAAR CONCLUSIONS AND COMPARISONS Chapter 19. Physics of the kimberlite magmatism 1 INTRODUCTION 2 SOURCES OF THE KIMBERLITE MAGMATISM 3 MECHANISM OF CRACK PROPAGATION 4 VELOCITY OF CRACK PROPAGATION 5 THE ROLE OF VOLATILES IN THE ASCENT OF KIMBERLITES 6 ORIGIN OF SHEARED XENOLITHS 7 REPETITIVE CHARACTER OF THE KIMBERLITE MAGMATISM AND ITS EVOLUTION 8 CONCLUSION Chapter 20. Kimberlite: "The Mantle Sample" formed by ultrametasomatism 1 INTRODUCTION 2 MANTLE SOURCE AND KIMBERLITE PRODUCT 3 MELT PRODUCTION AND SEGREGATION 4 NON-UNIFORMITY OF SOURCE 5 SUMMARY Chapter 21. Subsolidus reactions in kimberlitic ilmenites: exsolution, reduction and the redox state of the mantle ABSTRACT INTRODUCTION SAMPLE DESCRIPTIONS AND LOCATIONS MINERAL CHEMISTRY ILMENITE-SPINEL RELATIONS TEMPERATURES AND OXYGEN FUGACITIES DISCUSSION CONCLUSIONS ACKNOWLEDGMENTS Chapter 22. An experimental and theoretical analysis of partial melting in the system KAlSi04- CaO- MgO- Si02- C02 and applic 1 INTRODUCTION 2 EXPERIMENTAL METHODS 3 RESULTS 4 LIQUID COMPOSITIONS 5 MAGMA GENESIS 6 CONCLUSIONS Chapter 23. The formation of kelyphite and associated sub-kelyphitic and sculptured surfaces on pyrope from kimberlite 1 INTRODUCTION 2 PETROGRAPHY OF KELYPHITE 3 OBSERVATIONS ON GARNET FROM KIMBERLITE CONCENTRATES 4 SOME PECULIARITIES OF KELYPHITIZED PERIDOTITIC GARNET 5 ORIGINS FOR KELYPHITE AND CORONAS 6 SCULPTURING OF GARNET FROM KIMBERLITE 7 CONCLUSIONS 8 ACKNOWLEDGEMENTS Chapter 24. Compositions of fluids in equilibrium with peridotite: implications for alkaline magmatism-metasomatism 1 INTRODUCTION 2 FLUIDS: VOLATILE SPECIES 3 FLUIDS: DISSOLVED SOLIDS 4 PETROLOGIC APPLICATIONS ACKNOWLEDGMENTS Chapter 25. Kimberlite and the evolution of the Mantle 1 INTRODUCTION 2 THE DEPLETED RESERVOIR 3 THE ENRICHED RESERVOIR 4 THE KIMBERLITE-MORB CONNECTION 5 THE KIMBERLITE-KREEP RELATION 6 DISCUSSION 7 ACKNOWLEDGEMENTS Chapter 26. Volume in stabilities in the mantle as a possible source for kimberlite formation 1 INTRODUCTION 2 DISSOLVING FLUIDS 3 ERUPTION MODEL Chapter 27. Kimberlitic magmatism in the eastern united states: relationships to mid-atlantic tectonism INTRODUCTION GENERAL GEOLOGY AGES GEOTHERMOBAROMETRY DISCUSSION ACKNOWLEDGEMENTS Chapter 28. Kimberlites of Southern Africa - Are They Related To Subduction Processes? 1 INTRODUCTION 2 SHALLOW OR LOW-ANGLE SUBDUCTION 3 LOW-ANGLE SUBDUCTION UNDER SOUTHERN AFRICA? 4 KIMBERLITES AND SHALLOW SUBDUCTION 5 ULTRAMAFIC XENOLITHS AND DIAMONDS REFERENCES