Cambridge University Press 978-0-521-86392-6 - Rock Fractures in Geological Processes Agust Gudmundsson Index More information Index absolute tension 14 breccias accuracy 20, 21 density of 54 Anderson’s theory of faulting 36 Young’s modulus of 99, 178 angle of internal friction 194, 195 brittle angle of repose 194 deformation 16, 41, 51 anisotropic material 90 failure 19, 190–223 anisotropic rocks 18 failure and strength 190–193 holes in 176 fault zone 214 aperture (of fractures) 18, 21, 31 fracture 1, 10 of hydrofractures 270, 272 brittle-ductile transition 140–144, 213–223, 566 of tension fractures 239, 263, 265, 270 strain and 141 aperture variation 266–269 bulk modulus 96, 105 numerical models of 395 apparent dip 14 carbonates 101 arrest of fractures 64, 176, 177, 179–180, 289, 335, cataclasite 142 382–388, 447–450 cataclastic flow 143 aspect (length/thickness) ratios of mineral veins 537 cavity aspect ratio definition of 153 of cavities 173 stresses around 167–172 of dykes 336 censoring 345 of veins 400, 516 chemical bonds 101 atom 100 circular hole 162–167, 172–181 atomic view of elasticity 100–106 coefficient of internal friction 194 attitude of fractures 14, 16 cohesion 194 axes, principal 35 cohesionless material 194 axial collapse caldera 529 compression 43 columnar joints 7, 127, 261, 324, 327 extension 43 compliance 13 component of stress 8 stress 43 composite materials 289, 294, 384 tension 43 compressive force 31 compressive regime bar, elastic 13 Griffith criterion and 212 basin, stress in 43, 112 compressive strength 11 bedding plane 15 from the stress-strain curve 192 biaxial compressive stress 8 compression 45 as positive 8 compressive field 216 cone sheets 338–339, 535 tension 43 confining pressure 135, 142, 204, 298, 567 body forces 30 conglomerate 37 bond energy, of atoms 105 conjugate faults 197, 222, 361 boundary conditions constitutive equation 10 geometric 17 contact, between layers 15 loading 17 continuum mechanics 29 breakout 164 controlling dimension, of a fracture 257 570 © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-0-521-86392-6 - Rock Fractures in Geological Processes Agust Gudmundsson Index More information 571 Index convergent plate boundaries 43, 45, 236, 244 dip 14 Cook-Gordon debonding (delamination) 159, 384 dip-slip fault 15 core, fault 299–302, 439–455 low-angle 354 Coulomb normal 354 criterion 19, 36, 45, 195–203 reverse 354 envelope of failure 195 thrust 354 line of failure 196 overthrust 354 material 193–195 discontinuity 14 crack 2, 14 dislocation 144 displacement modes of 260–265 dislocation geometries of 255–260 edge 144 Griffith (Griffith crack) 205–212, 222, 326, 416 screw 144 mathematical model of 401 displacement 66–71 mode I 260–265 definition of 63 mode II 260–265 field 66 mode III 260–265 of a fault 15, 16, 255–276 models of 255–276 vector 66–71 resistance 211 distortion 40 crack-extension force 288 divergent plate boundaries 14, 69, 81, 236, 246 creep 10, 513 driving crystal plasticity 143–144 pressure 239, 525–529 crystal slip line 8 shear stress 192 cubic law 470–476 stress 237 curtailment 345 ductile behaviour 10, 11 damage zone, fault 299–302, 439–455 deformation 1, 20, 141, 143–145 darcy (a unit) 469 failure 190 Darcy’s law 466–470, 482, 484, 503 fracture 10 deflection of fracture 291–294, 382–388, strain 141 447–450 ductility, of rock 140 deformation 8, 76 Dundurs parameters 387 brittle 16, 41, 51 dyke 4, 7, 49, 66–69, 335–338 ductile 1, 20, 141, 143–145 sandstone 513 elastic 10, 134, 141, 294 dynamic (absolute) viscosity 21, 468, 471 heterogeneous 76 dynamic moduli (elastic constants) 19 homogeneous 76 inhomogeneous 76 earthquakes 16, 18, 133, 192, 513 plastic 10, 140, 214 Earth’s crust, stresses in 8 rigid-body rotation 64 Earth’s free surface 174 rigid-body translation 64 edge dislocation 144 surface 169, 400–404 effective stress 201, 203 degree of connectivity between pores 469 elastic 10 deviatoric stress 40–41 behaviour 10 distortion and 40 constants 95–109 deviatoric stress reduction, brittle deformation constants, atomic view of 100–106 and 41 constants, ranges of values of 97, 98 dextral strike-slip faults 15, 197, 243, 275, 281 deformation 10, 134, 141, 294 differential stress 126, 243 inclusion 154 diffusion 143, 144 linear (linear elastic behaviour) 10 diffusional flow 143 mismatch 384–388 dilatancy, microcracking and 134 moduli 19, 95, 99, 561–563 dilatation 78 non-linear (non-linear elastic behaviour) 90, dilation 78 91, 99 distortion and 71 resilience 120 mean stress and 40 electric forces 101 dimensions, of a quantity 21 electron 100 © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-0-521-86392-6 - Rock Fractures in Geological Processes Agust Gudmundsson Index More information 572 Index element 100 nucleation, minimum depth of 427 elevation head 471 oblique slip 15, 367–368 elliptical hole 156–161 relay ramps of 357, 430 fracture modelled as 160 reverse 7, 15 elongation 72, 77 right-lateral 15, 243, 361 empirical failure criteria 203–205 rocks 156, 214, 300, 442 en echelon fractures 362, 419–429 sinistral 15, 16 energy of a strained body 91, 118–120 slickensides 15, 367–368 energy release rate 211–212, 222, 289, 296–309, slip, evolution of 450–455 384–388, 447–449 soft linked 359 engineering methods for stress measurement 18 strike-slip 15 engineering strain 72 throw 15, 16 envelope, Mohr’s 203–204 trace 362 equilibrium, lithostatic 110–111, 167, 170 transfer 361, 359 evolution of fault slip 450–455 fault zones 20, 141, 142, 156, 213–223, 300–302 excess pressure 45, 526 ground-water flow and 496 in a reservoir 239 versus faults, definition 354–355 excess pressure gradient 527, 536, 542 local stresses and 441–447 exfoliation 187 faults and fault zones 354–355 exfoliation fractures (joints) 329 faults, Anderson’s theory of 244, 236 extension 8, 11, 72, 73 faults, classification of 36 axial 43 fibers, mineral 333 uniaxial 100 field measurements of fractures 342–346 extension fractures 14, 233–243, 319–346, 373–405, field, of lines of forces 158 525–540 fissure 357 in relation to stress 235 fissure swarm 66–69, 71, 84, 357 types of 235 fixed-grip (constant) displacement 210 extensional strain 79 flat jack, stress measurements using 18 flats 358 flexural rigidity 348 failure flow channelling 473 brittle 19, 190–223 flow criterion, plastic 19 ductile 10 flow shear 19, 190–223, 417–419 of magma 538, 545–546 strength and 190–193 of oil 469–484, 525–540 failure criteria 19, 20 straight 472 combined criterion 213–214 ductile 143 criterion for solids 19 radial 472 fatigue 11 fluid pressure fault aperture and 507–508 as distinct from a fault zone 358 total 167, 168, 201 core 299–302, 439–455 fluid transport damage zone 299–302, 439–455 in the fault core 510–512 dextral 15, 197, 243, 275, 281 in the fault damage zone 508–510 dip-slip 15 orthogonal fracture sets and 475–476 displacement 15, 16, 255–276 single fracture set and 473–475 footwall of 15, 16, 354 fluid-driven fracture, as a type of an extension growth of 430–438 fracture 235 hanging wall of 15, 16 fluid-filled reservoirs 47 hard linked 359 focal mechanisms, stresses from 18 heave of 15, 16 force 6 initiation 416–429 intensity of 6 left-lateral 15, 16, 243 forces listric 358 between atoms, attractive 101 local stresses of 441–447 between atoms, repulsive 101 normal 15 Fourier series, overpressure modelled by 391 © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-0-521-86392-6 - Rock Fractures in Geological Processes Agust Gudmundsson Index More information 573 Index fracture granular aperture of 18, 21, 31 flow 143 arrest (fracture arrest) 64, 66–69, 176, 177, 179, material 193–195 180, 289, 335, 382–388 media, Darcy’s law and 468 controlling dimension of 257 gravity, as body force 31, 49 definition of 1–2, 14 Griffith deflection 291–294, 382–388, 447–450 cracks 205–212, 222, 326, 416 frequency 344 criterion for rocks 19, 212–213, 419 hydraulic (hydraulic fracture) 137, 163, 181, 530, theory 205–212 533 ground-water flow 498–507 intensity 344 growth of faults 430–438 mechanics (fracture mechanics) 291–297 mechanics (fracture mechanics), Griffith theory and hard-linked fault 359 206 head permeability 477–486, 496–517, 525–540 elevation 471 plane 14 hydraulic 472 pressure 191 pressure 471 shear (shear fracture) 14 total 472 spacing 344 Heim’s rule 46 strike and dip dimension of 257 heterogeneous tension (tension fracture) 14 deformation 76 tip stresses of 390–404 material 90 toughness (fracture toughness) 212, 288–310, 289 rock 18 trace length of 343 strain 76 tunnel shaped 259 Hoek-Brown criterion 204 volumetric flow rate in 525–529 hole fractures circular 162–167, 172–181 basic types of 233–237 definition of 153 displacement modes of 260–265 elliptical 156–161 en echelon 362, 419–429 in anisotropic rock 176–180 field measurements of 342–346 homogeneous frequency of 344 deformation 76 geometric models of 255–260 material 90 hook-shaped 358, 359, 361 rock 18 hybrid 15 strain 76 mixed-mode 15, 255–265, 306, 324, 358, 384, 386, Hooke’s law 11–13 447 atomic view of 104 propagation of 118, 211, 288–310, 377–388, basic assumptions of 89 447–450 one-dimensional 89–92 spacing of 344 principal strains in terms of principal free surface 17, 48, 92 stresses 93 definition of 47, 51, 110, 121 principal stresses in terms of friction principal strains 94 angle of internal 194, 195 three-dimensional 92–95 coefficient of internal 194 hook-shaped fractures 358, 359, 361 law