Geology Reference
In-Depth Information
Fig. 8.3.
Marker surface offset by a
normal fault. Contours on the
fault are
thin lines
and con-
tours on the marker surface
are
heavier lines
. Throw on
the fault is 32 m, heave is
25.6 m, and the gap is 24.9 m
Fig. 8.4.
Marker surface offset by a re-
verse fault. Contours on the
fault,
heavy lines
; on the hang-
ingwall,
solid lines
; on the foot-
wall,
dotted lines
. The throw is
3.6 m, heave 34 m, and overlap
29.1 m
8.2.2
Stratigraphic Separation from a Structure Contour Map
Stratigraphic separation is found from the heave or throw by solving Eqs. 7.5 and 7.6
for
t
, g iv ing
t
=
H
cos
ρ
/cos
φ
,
(8.1)
t
=
T
cos
ρ
/sin
φ
,
(8.2)
where
t
= stratigraphic separation,
ρ
= the angle between the fault dip vector and the cross-
fault bedding pole,
= amount of fault dip,
H
= heave, and
T
= Throw. If bedding is horizon-
tal then the stratigraphic separation = Throw. The angle
φ
is found by one of the methods
in Sect. 4.1.1.1 or 4.1.1.2. The dip of the fault can be determined from the heave and throw as
ρ
φ
= arctan (
T
/
H
) ,
(8.3)
where
φ
= fault dip,
T
=throw, and
H
= heave.
