Geology Reference
In-Depth Information
Figure 3.42
Schematic
representation of
shear joints and
on a stereographic
projection,
assuming one set
(e.g. bedding or
cooling surface) is
horizontal. Second
diagram shows
typical pattern of
poles if the model
were tilted, say
through folding.
σ
1
β
σ
3
σ
2
Horizontal
bedding
North
North
x
x
x
xx
x
x
x
α
β
x
x
x
xx
x
β
x
x
Southeast
Bedding tilted by
α°
towards the southeast
Figure 3.43
Systematic joints,
whose geometries
of formation were
clearly in
uenced
by a pre-existing
mechanical
discontinuity (the
Peak Fault).
Ravenscar, near
Robin Hood
s Bay,
North Yorkshire,
England.
'
