Quantitative Textural Measurements in Igneous and Metamorphic Petrology

Cover......Page 1
Half-title......Page 3
Title......Page 5
Copyright......Page 6
Dedication......Page 7
Contents......Page 9
Acknowledgements......Page 11
1.1 Petrological methods......Page 13
1.2 Qualitative versus quantitative data......Page 14
1.3 What do I mean by texture?......Page 15
1.4 Information density and data sources......Page 16
1.6 Software applications for quantitative textural studies......Page 17
Notes......Page 18
2.1.1 Observations in three and two dimensions......Page 19
2.1.4 Textural development sequences......Page 21
2.2.1 Serial sectioning......Page 22
2.2.2 Optical scanning and confocal microscopy......Page 23
2.2.3 X-ray tomography......Page 24
2.3 Extraction of grain parameters from data volumes......Page 25
2.4 Destructive partial analytical methods......Page 26
2.4.2 Sample dissolution......Page 27
2.5.1 Surface preparation techniques and artefacts......Page 28
2.5.2 Electronic and associated analytical methods......Page 29
2.5.2.1 Backscattered electron images......Page 30
2.5.2.2 X-ray maps: EMP, SEM and Micro-XRF......Page 31
2.5.2.4 Orientation contrast imaging......Page 32
2.5.3 Optical analytical methods......Page 33
2.5.3.1 Transmitted light......Page 34
2.5.3.2 Reflected light......Page 35
2.5.3.3 Nomarski (DIC) microscopy......Page 36
2.5.4 Slabs and outcrops......Page 37
2.6 Extraction of textural parameters from images......Page 38
2.6.2 Manual image analysis......Page 39
2.6.3.1 Grey-scale images......Page 40
2.6.3.2 Multichannel images......Page 42
2.6.4 Computer-integrated polarisation microscopy......Page 44
2.7.2 Stereologically exact ‘global parameters’......Page 45
2.8 Verification of theoretical parameter distributions......Page 47
2.8.1 Chi-squared test......Page 48
2.8.2 Straight line distributions......Page 49
2.9 Summary......Page 50
3.1.1 What are size and size distributions?......Page 51
3.1.2 Linear size definitions......Page 52
3.2 Brief review of theory......Page 54
3.2.1 Primary kinetic crystallisation processes......Page 55
3.2.1.1 Nucleation of crystals......Page 56
3.2.1.2 Growth and solution......Page 58
3.2.2 Kinetic textures......Page 60
3.2.2.1 Steady-state crystallisation models......Page 61
3.2.2.2 Batch crystallisation: Marsh (1998) model......Page 63
3.2.3.1 Compaction and filter pressing......Page 64
3.2.3.2 Crystal accumulation......Page 67
3.2.3.3 Mixing of magmas and crystal populations......Page 68
3.2.4 Textural effects of equilibration......Page 71
3.2.4.1 Energy considerations......Page 72
3.2.4.2 Lifshitz–Slyozov–Wagner coarsening model......Page 74
3.2.4.3 Communicating Neighbours coarsening model......Page 77
3.2.4.5 Adcumulus growth......Page 78
3.2.5.1 Crystal deformation......Page 80
3.2.5.2 Crystal fragmentation (cataclasis)......Page 82
3.2.6 Closure in grain size distributions......Page 83
3.3.1.1 Solid materials......Page 86
3.3.1.2 Unconsolidated or disaggregated materials......Page 87
3.3.2.1 Grain outline width and length definitions......Page 88
3.3.3.1 ASTM mean and maximum size methods......Page 89
3.3.3.2 Grain number by shape independent intersection methods......Page 90
3.3.4.1 Nature of the problem......Page 91
3.3.4.2 Parametric solutions......Page 93
3.3.4.3 Distribution-free solutions......Page 94
3.3.4.4 Saltikov method......Page 97
3.3.4.5 Uncertainty analysis of the Saltikov method......Page 102
3.3.4.6 Data conversion methods used in early CSD studies: Wager and Grey methods......Page 103
3.3.5 Extraction of grain size distributions from projected grain data......Page 104
3.3.6 Verification and correction of grain size distributions using the volumetric phase proportion......Page 105
3.3.7 Graphical display of grain size distributions......Page 107
3.3.7.2 Semi-logarithmic: ‘CSD diagram’......Page 108
3.3.7.3 Bi-logarithmic: ‘Fractal’......Page 110
3.3.7.4 Lognormal and loghyperbolic......Page 111
3.3.7.5 Relative frequency and other methods......Page 113
3.4 Typical applications......Page 114
3.4.1.1 Plagioclase in a basaltic lava lake......Page 115
3.4.1.2 Plagioclase in basalt flows......Page 117
3.4.1.3 Plagioclase growth rates in basaltic magmas.......Page 119
3.4.1.4 Plagioclase in andesite......Page 120
3.4.1.5 Olivine in picrite......Page 124
3.4.1.6 Anorthoclase in phonolite......Page 125
3.4.2.1 Gabbro......Page 126
3.4.2.2 Troctolite and anorthosite......Page 128
3.4.2.3 Impact melt rocks......Page 130
3.4.3.1 Plagioclase in dacite......Page 131
3.4.3.2 Microlites......Page 132
3.4.3.3 Zircon in rhyolite tuffs and lavas......Page 133
3.4.4.1 Orthoclase, plagioclase and quartz in granite porphyry......Page 134
3.4.4.2 K-feldspar in granodiorite......Page 135
3.4.5.1 Diamonds......Page 136
3.4.5.2 Carbonates and chromites......Page 138
3.4.5.3 Chondrules and minerals in meteorites......Page 139
3.4.5.4 Hematite in pseudotachylytes......Page 140
3.4.6.1 Garnet......Page 141
3.4.6.2 Accessory minerals......Page 142
3.4.7.1 Olivine in mantle lherzolites......Page 143
3.4.7.3 Broken blocks and crystals......Page 144
Notes......Page 146
4.1 Introduction......Page 147
4.2.1.1 Equilibrium forms......Page 148
4.2.1.3 Solution forms......Page 149
4.2.2 Shapes of deformed crystals......Page 150
4.2.3 Dihedral angles of crystals in rocks......Page 151
4.3.1 Three-dimensional analytical methods......Page 155
4.3.2 Section and surface analytical methods......Page 156
4.3.3.2 Intersection data......Page 157
4.3.3.3 Projection data......Page 160
4.3.4 Extraction of grain boundary parameters......Page 161
4.3.4.1 Fractal analysis of grain shapes......Page 162
4.3.4.3 Fourier analysis of grain shapes......Page 163
4.3.4.4 Shape parameters used in sedimentology......Page 165
4.4.1 Undeformed crystalline rocks......Page 166
4.4.1.1 Plagioclase......Page 167
4.4.1.2 Zircon......Page 169
4.4.1.3 Other minerals......Page 170
4.4.2.1 Sutured quartz grain boundaries......Page 172
4.4.3 Dihedral angles......Page 173
Notes......Page 176
5.1 Introduction......Page 177
5.2.1.1 Crystallisation from a magma......Page 178
5.2.2.1 Property changes during solidification......Page 179
5.2.2.2 Magmatic deformation......Page 180
5.3 Introduction to fabric methodology......Page 182
5.4.2 Section and surface analytical methods......Page 183
5.4.3.2 Intercept (intersection) method......Page 184
5.5.1 Optical analytical methods: regular and universal stages......Page 186
5.5.2 Computer-integrated polarisation microscopy......Page 187
5.5.3 Electron backscatter diffraction (EBSD)......Page 188
5.6.1 Anisotropy of magnetic susceptibility......Page 189
5.6.2 Anisotropy of (partial) anhysteretic remanent magnetisation......Page 191
5.6.3 Other integrated (bulk) analytical methods......Page 192
5.7.1 Individual grain orientation display......Page 193
5.7.2 Mean orientation from individual data......Page 194
5.7.3 Integration of 2-D section data into a 3-D orientation ellipsoid......Page 195
5.8.1 Flow in lavas......Page 196
5.8.1.1 Mafic and intermediate lavas......Page 197
5.8.2 Flow in dykes......Page 200
5.8.3.1 Mafic rocks......Page 203
5.8.3.2 Granitoid intrusions......Page 206
5.8.4 Solid-state deformation......Page 208
5.8.5 Fabric development in pyroclastic rocks......Page 209
Notes......Page 210
6.1 Introduction......Page 211
6.2.1 Nucleation of crystals......Page 212
6.2.2 Geochemical self-organisation......Page 213
6.2.3 Grain aggregation and agglutination......Page 215
6.3 Methodology......Page 216
6.3.2 Section and surface analytical methods......Page 217
6.3.3.1 Nearest-neighbour distance (‘big’ R)......Page 218
6.3.3.2 Cluster analysis......Page 219
6.3.3.3 Touching crystals......Page 220
6.3.4.1 Mineral point correlations......Page 222
6.3.4.2 Box-counting method......Page 223
6.4.2 Igneous rocks......Page 224
7.1 Introduction......Page 228
7.2.2 Magmas and partially molten rocks......Page 229
7.2.3.1 Nucleation and growth of bubbles......Page 231
7.2.3.2 Bubble size distributions and shapes......Page 233
7.3 Methodology......Page 234
7.3.1.2 Image analysis method......Page 235
7.3.2.2 Three-dimensional imaging techniques......Page 236
7.3.3.2 Conversion of two-dimensional data to 3-D pore parameters......Page 237
7.4.1 Display of pore size distributions......Page 238
7.4.2 Overall pore size parameters......Page 239
7.5.1 Volcanic rocks......Page 240
Notes......Page 243
8.2 Chapter 2: General analytical methods......Page 244
8.4 Chapter 4: Grain shape......Page 247
8.6 Chapter 6: Grain spatial distributions and relations......Page 248
References......Page 249
Index......Page 272