728 Index
Subsolidus (continued)
metasomatism, 291
reactions in magmatic rocks, 118–19
See also Solidus
Subsolvus granite, 104, 105f
Sudbury (Ontario), 286f, 331t
Sulfides, stability in metamorphic systems, 508
Sulfur, in magma, 78
Superior Province (Canada), 615, 619f, 620f,
622–3, 637f, 639f, 647f
Supracrustal rock sequences, 613, 615, 617,
622
Surface diffusion, 126
Surface free energy
crystallization and, 131–2, 134
intergrain and textural modification, 141,
142f
Surface tension, 132
Surges, pyroclastic, 261f, 264f, 266–7
Surroundings of a system, 11
Surtseyan eruption, 261f, 269
Syenite, 20t, 29f, 206f, 390
Symplectite texture, 454, 455f, 484f, 528
System, 11
Tambora (Indonesia) volcano, 84
Tauern Window, 574–6
Taupo (New Zealand) volcanic zone, 270, 271,
339, 340f, 341f, 378, 379f
Tectonic settings
of magmatism, 8f, 285f, 643
of metamorphism, 426–30, 564–606, 643,
648
problematic for Precambrian terranes,
649–51
and state of stress, 220–1
See also Plate tectonics and Petrotectonic
associations
Tectonic thickening and heating, 285
Tectonite, 416, 528–61
fabric, see Fabric, metamorphic
L-, L–S-, S-, 448–50
Tectonothermal factors in metamorphism, 431,
439, 441, 564–606
Temperature
in Earth and geothermal gradient, 5–8
as intensive variable, 53
perturbations of causing partial melting,
384–6
See also Heat
Tension, surface, 132
Tephra, see Pyroclasts
chronology, 266
Tephrite, 32f, 33f
Ternary feldspar equilibria, 100, 104–9
Texture, 14
See also Fabric and specific types of, e.g.
amygdaloidal
Thermal
conduction (diffusion), 4–6, 123f, 130–1,
197–200
conductivity, 130
convection, 6–8, 201–5
energy, 3
expansion, 195
gradient, 5
relaxation in orogens, 565, 566f
upper stability limit for minerals, 115
transfer time, 131
See also Heat
Thermobarometer (geo-, mineral)
crystal-melt equilibria and, 117–18
isotope, 45
metamorphic mineral assemblage, 437, 485,
513–17, 566, 602
oxygen buffers, 66
and P–T–t paths, 566
Thermochemical convection, 203–5
Thermodynamics, 51–66
Thermomechanical feedback, 191, 284
Tholeiite
abyssal, 350
basalt, 37
chemical composition, 99t, 358t, 360t,
369t, 373t
crystal-melt equilibria in, 98f, 100f
density of melt, 195f
immiscible melts in, 322–3
trace elements, normalized, 304f
Tholeiitic
arc rocks, 35–6, 37f, 372–5
differentiation trend, 35–6, 337f
See also Skaergaard trend
Thompson, James B. Jr, 14, 470, 505–6
Thread-lace scoria, 143f
Tides in solid Earth, thermal energy from, 9
Tonalite, 29f, 30f
dehydration melting of, 310t
partial melts of, 311f
Tonga arc, 36f, 37f, 339, 340f, 378
Topaz rhyolite, 388
Total alkalies-silica (TAS) diagram, 25f, 26f,
32f, 36f
Trace elements, 19, 23t, 37–40
adakite, 43f
arc signature of, 303–5, 375
A-type felsic rocks, 388t, 389f
behavior during fractional crystallization,
320–2
behavior during partial melting, 299–300
bulk partition coefficient, 39
chondrite, 43t
flood plateau basalts, 366f, 369t
Hawaiian rocks, 360, 361f
highly alkaline rocks, 306f, 396t
Himalayan granite, 387t
immiscible melts, 323t
island arc volcanic rocks, 303–4, 373t
lunar basalt, 43f
mantle peridotite, 293f
metasomatized mantle peridotite, 293f
mid-ocean ridge basalt (MORB), 350–1
normalized diagrams, 42–3
partition coefficients, 38–43
petrogenetic modeling, 37–44, 299, 320,
321f
primitive mantle, 43t
Sierra Nevada batholith, 385t
Trachyandesite, 21t, 32f
Trachybasalt, 21t, 32f
Trachyte, 20t, 32f, 33f
Trachytic fabric, 155, 175
Translation gliding (slip), 532–43
Transport phenomena, 122, 123f
Transposition, 421, 423f, 451f, 552f
Trench, ocean, 285f, 301f, 340f, 372, 380f
Triple point, 88, 478f
Tristan da Cunha, 36f, 346, 356, 364f
Troctolite, 30f, 232f
Trondhjemite, 30f, 306
partial melts, 311f
Tschermak end member pyroxene, 482
TTG (tonalite, trondhjemite, granodiorite),
613, 618, 619f, 633–6, 650f
magma generation, 311, 621f, 634, 635
Tubes, lava, 245, 247f
Tuff, 27f
ash-flow, 270f, 271, 274f, 275f
fused, 171
lapilli, 170f, 172f, 173f
welded, 271
Tuff cone, 245f, 246f, 269
Tuff ring, 232f, 269
Turner, Francis J., 287, 438
Twin
deformation, 460f, 531f, 532f
gliding, 533–5
Ultramafic rocks, 28, 30f
Undercooling, see Crystallization of magma
Underplating, see Magmatic, underplating
Undulatory optical extinction, 460f, 532, 541,
544f
Univariant
boundary line, 478f, 479f
equilibrium, 88
Unzen (Japan) volcano, 271
Upheaved plug, 255
Uplift, resurgent, 277
Valles (New Mexico) caldera, 276f, 277f
Vapor-phase crystals, 166, 173f, 275
Variance, phase rule and, 87–8
Variation diagrams, 23–4
to model magmatic differentiation, 317f,
318f, 625–7
Varioles, 625
Vein(s), 431, 432f, 466, 498
crack–seal, 466, 503, 545, 546f
metasomatic in mantle rock, 291–3, 307
Vein-plus-wall-rock melting, 307
Velocity, terminal and Stokes’s law, 197
Vesicles and vesicular fabric, 82, 165
Vesiculation, 80f, 142–6, 165
Vesuvius (Italy) volcano, 262, 270, 279
Viscosity, 7, 74, 123f, 124
apparent (non-Newtonian), 190–4
calculation of, 125
coefficient of, 124
crystallinity and, 191f
degree of polymerization and, 74, 124
diffusion in melts controlled by, 128
melt, 124
Newtonian, 186
Viscous flow, 186
Vitroclasts and vitroclastic fabric, 166–9
Vitrophyre and vitrophyric texture, 27, 151f,
152f, 156f, 157
Volatiles, 19, 75
critical point for, 75
exsolution from melts, 79–80, 142–6,
165–70, 259
chemical interaction between species, 80
in melts, 75–82, 89–90, 115
pressure, 75–6
role of in extrusion of lava, 242
role in partial melting, 283, 287
solubilities in melts, 76–9
specific volume of, 76f
See also Fluid