PREFACE ....................................................... vII
ACKNOWLEDGEMENTS ............................................... IX
LIST OF TABLES ................................................. XV
SOME COMMON ABBREVIATIONS USED IN THE TEXT .................... xix
PART ONE. Magmatism and global tectonic processes ............... 1
CHAPTER 1. Relation of present-day magmatism to global
tectonic processes ................................... 3
1.1. Introduction ............................................... 3
1.2. Characteristic magma series associated with specific
tectonic settings .......................................... 7
Further reading ........................................... 11
CHAPTER 2. Geochemical characteristics of igneous
rocks as petrogenetic indicators .................... 13
2.1. Introduction .............................................. 13
2.2. Chemical analysis of igneous rocks ........................ 14
2.1. Chemical variation diagrams ............................... 14
2.4. Geochemical characteristics of primary magmas ............. 21
2.5. Isotopes as petrogenetic indicators ....................... 22
2.6. Geochemical criteria for the identification of
the palaeotectonic setting of ancient volcanic
sequences ................................................. 32
Further reading ........................................... 34
CHAPTER 3. Partial melting processes in the Earth's
upper mantle ........................................ 37
3.1. Introduction .............................................. 37
3.2. The physical state of the upper mantle .................... 38
3.3. Chemical composition and mineralogy
of the upper mantle ....................................... 44
3.4. Partial melting processes in the upper mantle ............. 58
3.5. The basaltic magma spectrum in relation
to partial melting processes .............................. 67
3.6. Segregation and ascent of magma ........................... 70
Further reading ........................................... 72
CHAPTER 4. Processes which modify the composition of
primary magmas ...................................... 73
4.1. Introduction .............................................. 73
4.2. Convection and mixing in magma chambers ................... 78
4.3. Fractional crystallization ................................ 82
4.4. Crustal contamination ..................................... 89
4.5. Zone refining ............................................. 96
4.6. Liquid immiscibility ...................................... 97
4.7. Gaseous transfer processes ................................ 97
Further reading ................................................ 97
PART TWO. Magmatism at constructive plate margins .............. 99
CHAPTER 5. Mid-ocean ridges ................................... 101
5.1. Introduction ............................................. 101
5.2. Simplified petrogenetic model ............................ 104
5.3. Nature of the oceanic crust .............................. 106
5.4. Structure of mid-ocean ridges ............................ 110
5.5. Heat flow and metamorphism ............................... 119
5.6. Convection systems at constructive.
plate margins ............................................ 124
5.7. Partial melting processes ................................ 125
5.8. Magma storage and release ................................ 126
5.9. Petrography of mid-ocean ridge.
basalts .................................................. 129
5.10.Chemical composition of erupted.
magmas ................................................... 132
5.11.Detailed petrogenetic model .............................. 145
Further reading ............................................... 149
PART THREE. Magmatism at destructive plate margins ............ 151
CHAPTER 6. Island arcs ........................................ 153
6.1. Introduction ............................................. 153
6.2. Simplified petrogenetic model ............................ 154
6.3. Structure of island arcs ................................. 157
6.4. Earthquakes and magma genesis ............................ 158
6.5. Thermal structure and partial melting processes .......... 159
6.6. Segregation, ascent and storage of magma ................. 162
6.7. Characteristic magma series .............................. 164
6.8. Spatial and temporal variations in island-arc
magmatism ................................................ 167
6.9. Surface volcanic features ................................ 168
6.10.Petrography of island-arc volcanic rocks ................. 169
6.11.Chemical composition of erupted magmas ................... 172
6.12. Detailed petrogenetic model ............................. 188
Further reading ............................................... 190
CHAPTER 7. Active continental margins ......................... 191
7.1. Introduction ............................................. 191
7.2. Simplified petrogenetic model ............................ 196
7.3. The structure of active continental margins .............. 198
7.4. Thermal structure and partial melting processes .......... 201
7.5. Magma storage in the crust ............................... 203
7.6. Petrographic characteristics of the volcanic and
plutonic rocks ........................................... 206
7.7. Chemical composition of the magmas ....................... 208
7.8. Detailed petrogenetic model .............................. 223
Further reading .......................................... 225
CHAPTER 8. Back-arc basins .................................... 227
8.1. Introduction ............................................. 227
8.2. Simplified petrogenetic model ............................ 229
8.3. Petrography of the volcanic rocks ........................ 231
8.4. Chemical composition of the erupted magmas ............... 231
8.5. Detailed petrogenetic model .............................. 239
Further reading .......................................... 241
PART FOUR. Magmatism within plates ............................ 243
CHAPTER 9. Oceanic islands .................................... 245
9.1. Introduction ............................................. 245
9.2. Simplified petrogenetic model ............................ 250
9.3. Crustal structure of oceanic islands ..................... 253
9.4. Partial melting processes ................................ 255
9.5. High-level magma storage ................................. 256
9.6. Petrography of oceanic-island volcanic rocks ............. 258
9.7. Chemical composition of erupted magmas ................... 261
9.8. Detailed petrogenetic model .............................. 282
Further reading ............................................... 285
CHAPTER 10.Continental tholeiitic flood basalt provinces ...... 287
10.1.Introduction ............................................. 287
10.2.Simplified petrogenetic model ............................ 291
10.3.Crustal structure and magma storage reservoirs ........... 294
10.4.Crustal contamination of magmas .......................... 295
10.5.Petrography of the volcanic rocks ........................ 296
10.6.Chemical composition of the erupted magmas ............... 298
10.7.Detailed petrogenetic model .............................. 321
Further reading .......................................... 323
CHAPTER 11.Continental rift zone magmatism .................... 325
11.1.Introduction ............................................. 325
11.2.Simplified petrogenetic model ............................ 332
11.3.Crust and upper mantle structure ......................... 335
11.4.Petrography of the volcanic rocks ........................ 339
11.5.Chemical composition of the erupted magmas ............... 342
11.6.Detailed petrogenetic model .............................. 371
Further reading ......................................... 374
CHAPTER 12.Potassic magmatism within continental plates ....... 375
12.1.Introduction ............................................. 375
12.2.Simplified petrogenetic model ............................ 380
12.3.Partial melting processes in the upper mantle ............ 384
12.4.Petrographic characteristics of kimberlites and
ultrapotassic rocks ...................................... 388
12.5.Chemical composition of kimberlites and ultrapotassic
rocks .................................................... 391
12.6.Detailed petrogenetic model .............................. 411
Further reading .......................................... 416
APPENDIX ...................................................... 417
Approximate ranges ofD values for the partitioning of
trace elements between the common rock-forming minerals
and liquids of basic—intermediate composition
BIBLIOGRAPHY .................................................. 423
INDEX ......................................................... 457
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