Inhalt

1 Introduction.- 1.1 Basalt and its Relation to Leucite-Bearing Mafic and Ultramafic Rocks.- 1.2 Mineralogical Composition and Other Geochemical Peculiarities of Leucite-Bearing Rocks.- 1.3 A Brief Summary of the Hypotheses of Origin of Leucite-Bearing Rocks.- 1.4 Objective of This Study.- 2 Nomenclature and Petrography of Leucite-Bearing Rocks.- 2.1 Nomenclature.- 2.1.1 Italite.- 2.1.2 Leucitite.- 2.1.3 Olivine Leucitite.- 2.1.4 Melilite Leucitite.- 2.1.5 Katungite.- 2.1.6 Leucite Tephrite.- 2.1.7 Leucite Basanite.- 2.1.8 Melilite-Nepheline Leucitite.- 2.1.9 Jumillite.- 2.1.10 Verite.- 2.1.11 Wolgidite.- 2.1.12 Fitzroyite.- 2.1.13 Mamilite.- 2.1.14 Cedricite.- 2.1.15 Wyomingite.- 2.1.16 Orendite.- 2.1.17 Madupite.- 2.1.18 Potassium-Rich Ankaratrite.- 2.1.19 Mafurite.- 2.1.20 Shonkinite.- 2.1.21 Absarokite, Banakite, and Shoshonite.- 3 Mineralogical Composition of Leucite-Bearing Rocks.- 3.1 Leucite.- 3.2 Nepheline.- 3.3 Kalsilite.- 3.4 Kaliophilite.- 3.5 Sanidine.- 3.6 Plagioclase.- 3.7 Pyroxene.- 3.8 Olivine.- 3.9 Mica.- 3.10 Potash Richterite.- 3.11 Melilite.- 3.12 Analcite.- 3.13 Accessory Minerals.- 3.13.1 Sodalite.- 3.13.2 Apatite.- 3.13.3 Priderite.- 3.13.4 Wadeite.- 3.13.5 Other Minerals.- 4 Minor and Trace Element Geochemistry, Initial 87Sr/86Sr Ratios and Oxygen Isotopic Ratios of Leucite-Bearing Rocks.- 4.1 Trace Element Geochemistry.- 4.2 The Initial 87Sr/S6Sr Ratios of Highly Potassic Lavas and Other Rock Types.- 4.3 ? 18O-contents of Leucite-Bearing Rocks.- 5 Distribution of Leucite-Bearing Rocks.- 5.1 Volcanic Fields, East and Southeast of Ruwenzori, Uganda.- 5.2 Birunga Volcanic Province.- 5.3 Leucite-Bearing Rocks of West Kimberley, Australia.- 5.4 Leucite-Bearing Rocks of New South Wales, Australia.- 5.5 Leucite-Bearing Rocks of Indonesia.- 5.6 Volcanic Fields of Highwood Mountains, Montana (USA).- 5.7 Potassic Rocks of Navajo-Hopi Province (USA).- 5.8 Leucite-Bearing Rocks of Leucite Hills, Wyoming (USA).- 5.9 Leucite-Bearing Rocks of Italy.- 5.9.1 Monti Vulsini.- 5.9.2 Vico Volcanic Complex.- 5.9.3 Monti Sabatini.- 5.9.4 Colli Albani (Alban Hills).- 5.9.5 Phlegrean Fields.- 5.9.6 Somma-Vesuvius.- 5.9.7 Roccamonfina.- 5.9.8 Volcanic Activity in the Eolian Arc Region.- 5.10 Volcanic Provinces of Spain.- 5.11 Leucite-Bearing Lamprophyres of Eastern India.- 5.12 Leucite-Bearing Rocks of the Laacher See and Other Areas of West Germany.- 5.13 Leucite-Bearing Rocks of the Tristan da Cunha Islands.- 5.14 Leucite-Bearing Rocks of Manchuria, China.- 5.14.1 Wu-ta-lien-chih.- 5.14.2 Erh-Ko.- 5.14.3 Chi-hsing Shan.- 5.15 Leucite Bearing Rocks of Utsuryo Island (Ullung-do), Korea.- 6 Conditions of Formation of Leucite-Bearing Mafic and Ultramafic Rocks.- 6.1 Chemical Conditions.- 6.2 Silica Activity in Leucite-Bearing Rocks.- 6.3 Physical Conditions.- 7 Leucite-Bearing Ternary Joins and Systems.- 7.1 The System Nepheline-KalsiliteSiO2.- 7.2 The System Diopside-Leucite-SiO2.- 7.3 The System Anorthite-Leucite-SiO2.- 7.4 The System Diopside-Sanidine-Albite.- 7.5 The System Diopside-Nepheline-Sanidine.- 7.6 The System Nepheline-Leucite-Anorthite.- 8 Leucite-Albite Incompatibility.- 8.1 The Join Leucite-Albite.- 8.1.1 Composition of Alkali Feldspars in the Leucite-Albite-Join.- 8.2 The Join Leucite-Albite-Anorthite.- 8.2.1 Compositions of Ternary Feldspars in the Leucite-Albite-Anorthite Join.- 8.3 Petrological Implications.- 9 Leucite- and Feldspar-Bearing Quaternary Joins and Systems.- 9.1 The System Forsterite-Diopside-Leucite-Anorthite.- 9.1.1 The Join Forsterite-Diopside-Anorthite.- 9.1.2 The Join Forsterite-Anorthite-Leucite.- 9.1.3 The Join Diopside-Leucite-Anorthite.- 9.1.4 Paragenesis.- 9.2 The System Diopside-Leucite-Anorthite-SiO2.- 10 The System Forsterite-Diopside-Akermanite-Leucite.- 10.1 The Join Diopside-Akermanite-Leucite.- 10.2 The Join Forsterite-Diopside-Leucite.- 10.3 The Join Forsterite-Akermanite-Leucite.- 10.4 The Join Forstente-Diopside-Akermanite.- 10.5 The Join Diopside-Akermanite-Leucite with 3% Forsterite.- 10.6 Paragenesis.- 10.6.1 Melilite Leucitite.- 10.6.2 Olivine Leucitite.- 10.6.3 Katungite.- 10.6.4 Olivine Melilitite.- 10.7 Course of Crystallization of Liquid in the System Forsterite-Diopside-Akermanite-Leucite.- 11 The System Diopside-Nepheline-Akermanite-Leucite.- 11.1 The Join Diopside-Nepheline-Akermanite.- 11.2 The Join Diopside-Nepheline-Leucite.- 11.3 The Join Nepheline-Akermanite-Leucite.- 11.4 The Join (Di38AK3Ne59)100?x-Lcx.- 11.5 Course of Crystallization of Liquid Within the System Diopside-Nepheline-Akermanite-Leucite.- 11.6 Paragenesis.- 11.7 Melilite-Plagioclase Incompatibility Problem in Leucite-Bearing Lavas.- 12 Solubility of KFe3+Si2O6 in Leucite.- 13 Survival of Leucite.- 13.1 Alteration of Leucite to Analcite.- 13.2 Pseudoleucite and its Genesis.- 14 Study of Leucite-Bearing Systems Under Different Pressures and the $${{P}{{{{H}{2}}O}}} - T$$ Stabilities of Phlogopite, Potassium-Rich Richtente, and Kaersutite.- 14.1 Leucite-Bearing System Under Different Pressures.- 14.2 The System KAlSiO4-Mg2SiO4 SiO2-H2O.- 14.3 Phlogopite Stability.- 14.4 Potassic Richterite and Kaersutite as Possible Sources of Potassium in the Upper Mantle.- 14.4.1 Stability of Potassic Richterite.- 14.4.2 Stability of Kaersutite.- 15 Study of Leucite-Bearing Rocks in Air and Under Various P-T Conditions.- 15.1 One-Atmospheric Studies on Leucite-Bearing Rocks.- 15.2 Studies of Synthetic and Natural Leucite-Bearing Rock Systems Under Different P-T Conditions.- 15.2.1 Experiments Under Low Water Pressures (up to 10 kb).- 15.2.2 Thermodynamic Considerations for the Conversion of a Katungite to a Phlogopite Pyroxenite at High Pressures.- 15.2.3 Study of a Synthetic Biotite Mafurite Glass at High Pressures.- 15.2.4 Study of a Synthetic Leucite Basanite and a Melilite-Nepheline Leucitite Between 10 and 25 kb.- 16 Leucite-Bearing Rocks and Their Relation to Kimberlites.- 16.1 Comparison of the Chemistry of Kimberlites and Leucite-Bearing Rocks.- 16.2 Possible Genetic Connection Between Potassic Rocks and Kimberlites.- 16.3 Experimental Study of a Synthetic Katungite Under $${{P}{{{{H}{2}}O}}} - T$$ and $${{P}{{C{{O}{2}}}}}$$ in Relation to Kimberlite Genesis.- 16.4 Experimental Study of Two Picrites with Reference to the Genesis of Kimberlite and Potassium-Rich Magma.- 17 Structural and Tectonic Control of Alkali Magmatism with Special Reference to Leucite-Bearing Lavas.- 17.1 Volcanism Associated with Rift Zones and Fault Systems.- 17.2 Tectonics in the East Eifel Area of W. Germany.- 17.3 Plate Tectonic Model for the Generation of Potassium-Rich Magma.- 17.3.1 Origin of Highly Potassic Magmas of Indo-Pacific and Calabrian Arcs.- 17.3.2 Genesis of Magmas of Roman Province.- 17.3.3 Genesis of Shoshonite.- 18 Generation of Potassium-Rich Mafic and Ultramafic Magma Capable of Producing Leucite-Bearing Rocks.- 18.1 Hypotheses Involving Assimilation and Contamination.- 18.1.1 Hypotheses of Shand (1931) and Rittmann (1933).- 18.1.2 Assimilation of Peridotite by a Basalt Magma (Holmes and Harwood 1932).- 18.1.3 Hypothesis of Williams (1936).- 18.1.4 Hypothesis of Gorai (1940).- 18.1.5 Carbonatite and Granite Assimilation Hypothesis of Holmes (1950, 1965).- 18.2 Hypotheses Involving Fractionation.- 18.2.1 Views of Holmes (1932) and Wade and Prider (1940).- 18.2.2 Eclogite Fractionation Hypothesis of O'Hara and Yoder (1967).- 18.3 Fractional Resorption of Mica and Amphibole (Bowen 1928).- 18.4 Zone-Refining Hypothesis of Harris (1957).- 18.5 Genesis of Potassic Rocks by Volatile Transport.- 18.6 Generation of Potassium-Rich Mafic and Ultramafic Magma by Partial Melting of Phlogopite-Bearing Ultramafic Upper Mantle.- 18.7 Summary and Conclusions.- References.