The Evolution of the Igneous Rocks

CONTENTS
PART ONE
CHAPTER I
THE PROBLEM OF THE DIVERSITY OF IGNEOUS ROCKS 3
CHAPTER II
LIQUID IMMISCIBILITY IN SILICATE MAGMAS 7
Theoretical Results of a Process of Unmixing 8
The Significance of Greig\'s Work on Actual Examples of Unmixing in Silicates 10
Supposed Examples of Immiscibility in Natural Magmas 13
CHAPTER III
FRACTIONAL CRYSTALLIZATION 20
General Considerations 20
Factors Bringing about Fractionation during Crystallization 21
CHAPTER IV
CRYSTALLIZATION IN SILICATE SYSTEMS 25
Binary System with Eutectic 26
Binary System with a Compound Having a Congruent Melting Point 27
Binary System with a Compound Having an Incongruent Melting Point 29
Binary System with More than One Compound Having an Incongruent Melting Point 31
Binary System Showing a Complete Series of Solid Solutions, without Maximum or Minimum Melting Temperature 33
Binary System Showing a Complete Series of Solid Solutions with a Minimum Melting Temperature 35
Binary System Showing a Complete Series of Solid Solutions with a Maximum Melting Temperature 36
Binary System with Limited Solid Solution Showing a Eutectic 36
Binary System with Limited Solid Solution and no Eutectic 38
Ternary System without Compounds or Solid Solutions 38
Ternary Systems with a Compound or Compounds Having Congruent Melting Points 39
Ternary System with a Binary Compound Having an Incongruent Melting Point 41
Ternary System Having a Ternary Compound with an Incongruent Melti1ng Point 44
Ternary System with a Binary Series of Solid Solutions 45
Ternary System with a Series of Binary Solid Solutions that Melt Incongruently 49
CHAPTER V
THE REACTION PRINCIPLE 54
CHAPTER VI
THE FRACTIONAL CRYSTALLIZATION OF BASALTIC MAGMA 63
General Considerations 63
The Early Separation of Both Plagioclase and Pyroxene 64
The Importance of the Early Separation of Olivine 70
The General Trend of the Fractional Crystallization of Basaltic Magma and the Formation of Biotite 79
Some Relations Involved in the Separation of Hornblende 85
Addendum 91
CHAPTER VII
THE LIQUID LINES OF DESCENT AND VARIATION DIAGRAMS 92
General Considerations 92
Factors Governing the Bulk Composition of a Rock 93
Relative Significance of the Different Classes of Rocks 94
Theoretical Shapes of the Curves of Variation of the Liquid 96
Possible Effects of the Separation of Hornblende 111
Variation of the Liquid Line of Descent 113
The Katmai Rock Series 114
Generalized Variation Diagram and Its Significance 122
CHAPTER VIII
THE GLASSY ROCKS 125
CHAPTER IX
ROCKS WHOSE COMPOSITION IS DETERMINED BY CRYSTAL SORTING 133
Introduction 133 
The Porphyritic Central Magma-type of the Mull Authors 134
Analogous Lavas from Other Regions 139
The Limitation of the Plagioclase Composition of Magmatic Liquids 141
Ultrabasic Types of the Hebrides 145
Peridotite Dikes of Skye 148
Margins of the Peridotite Dikes 150
Petrography of Individual Peridotite Dikes of Skye 151
Suggested Explanation of Contact Facies of the Dikes 157
The Olivine Basalts 159
Rocks Enriched in Both Olivine and Basic Plagioclase 164
Rocks Enriched in Pyroxene or Hornblende 165
General Consideration of the Ultrabasic Rocks and Summary of Conclusions 166
Banded Gabbro 168
A northosites 170
A Note on \"Magmatic Ore Deposits\" 172
Addendum by E. B. Bailey 173
CHAPTER X
THE EFFECTS OF ASSIMILATION 175
Heat Effects of Solution 175
The Question of Superheat 182
Equilibrium Effects between \"Inclusions\" and Liquids in Investigated Systems 185
Reaction Series 192
Effects of Magma upon Inclusions of Igneous Origin 197
Effects of Magma upon Inclusions of Sedimentary Origin 201
Effects of Basaltic Magma on Aluminous Sediments 207
The Action of Basic Magmas on Siliceous Sediments 214
Effects of Granitic Magma on Inclusions of Sedimentary Origin 215
Deductions to be Compared with Observed Results 219
Summary 220
PART TWO
CHAPTER XI
THE FORMATION OF MAGMATIC LIQUID VERY RICH IN POTASH FELDSPAR 227
CHAPTER XII
THE ALKALINE ROCKS 234
General Note 234
Trachytic Rocks 236
The Basalt-Trachyte Association of Oceanic Islands 240
Feldspathoidal Rocks 240
The Pseudo-Leucite Reaction and the Development of Some Nephelitic Rocks 253
CHAPTER XIII
LAMPROPHYRES AND RELATED ROCKS 258
General Characters 258
Olivine-bearing Lamprophyric Types 258
Experimental Studies of Related Mixtures 260
Nature of the Melilites 262
Space Relations of the Equilibrium Fields 263
Formation of Lime-rich Minerals in Alkalic Rocks 266
CHAPTER XIV
THE FRACTIONAL RESORPTION OF COMPLEX MINERALS AND THE FORMATION OF STRONGLY FEMIC ALKALINE ROCKS 269
CHAPTER XV
FURTHER EFFECTS OF FRACTIONAL RESORPTION 274
Reversal of Normal Order of Zoning 274
Limits of Resorption 275
Localized Resorptive Effects 276
Formation of Spine! in Ultrabasic Rocks 277
Origin of Picotite and Chromite 279
CHAPTER XVI
THE IMPORTANCE OF VOLATILE CONSTITUENTS 282
Introduction 282
Systems with Water 282
Gaseous TransFer 293
Proportions of the Volatile Constituents and the Probable Effects of Such Proportions 296
CHAPTER XVII
PETROGENESIS AND THE PHYSICS OF THE EARTH 303
The Broader Density Relations 303
Observations Throwing Light on the Physical Condition of Earth Shells 304
Earthquake-Wave Propagation 304
The Geothermal Gradient and the Radioactive Content of Rocks 306
Tidal Deformation and Distortional Seismic Waves 310
The Source of Magmas 311
Production of Basaltic Magma by Selective Fusion of Peridotite 315
CHAPTER XVIII
THE CLASSIFICATION OF IGNEOUS ROCKS 321
INDICES
General Index 325
Index of Systems 333
Index of Components and Compounds of Systems 334