Notations

1/v

Poisson’s number (m) the inverse of Poisson’s ratio [M₀L₀T₀, dimensionless]

C

cohesion or intrinsic shear strength of material [ML^-1T^-2]

   CDZ

composite deformation zone

C_f

cohesion or intrinsic shear strength along-foliation feature [ML^-1T^-2]

   DDZ

distributed deformation zone

E

Young’s modulus [ML^-1T^-2]

e

fracture aperture [L]

e_v

vertical compression [LL^-1, dimensionless]

   FPF

foliation parallel fracture

g

gravitational acceleration [LT⁻²]

h

depth [L]

   ISF

intermediate to high dip fracture

K

hydraulic conductivity [LT^-1]

k

permeability [L2]

K_f

fracture hydraulic conductivity [LT⁻²]

   LDZ

localized deformation zone

   MPa

megapascal [106 Pascals]

N

number of fractures per unit length [L⁻²]

ρ

density [ML−3]

p

fluid pressure [ML^-1T^-2]

R₁

Riedel shear [same sense of movement]

R₂

Riedel shear [opposite sense of movement]

SFF

single fracture fault

   SHF

subhorizontal fracture

S_Hmax,

maximum horizontal stress [ML^-1T^-2]

SVF

subvertical fractures

S_z

vertical stress [ML^-1T^-2]

T

definition depends on context, fluid flow – transmissivity [L2T^-1]

T

definition depends on context, material property – tensile strength [ML^-1T^-2]

t_f

intrinsic transmissivity [L3]

TFZ

throughgoing fracture zone

v

Poisson’s ratio [M0L0T0, dimensionless]

v

Darcy flux [L2T⁻²]

z

depth [L]

Δ_h

hydraulic head gradient [LL^-1, dimensionless]

μ

dynamic viscosity [ML⁻²T⁻²]

φ

friction angle [°]

σ₁

maximum principal stress [ML⁻²T⁻²]

σ₂

intermediate principal stress [ML⁻²T⁻²]

σ₃

minimum principal stress [ML⁻²T⁻²]

σ_h

horizontal stress [ML⁻²T⁻²]

σ_h°

initial horizontal stress [ML⁻²T⁻²]

σ_{h dol}

dolostone horizontal stress [ML⁻²T⁻²]

σ_{h mud}

mudstone horizontal stress [ML⁻²T⁻²]

σ_n

normal stress [ML⁻²T⁻²]

σ_v

vertical stress [ML⁻²T⁻²]

σ_v°

Initial vertical stress [ML⁻²T⁻²]

τ

shear stress [ML⁻²T⁻²]

θ

angle between shear fracture and σ₁ [°]