Geoscience Reference
In-Depth Information
8
(a)
4 m
13 m
20 m
13 m
25 m
8 m
15 m
maximum
throw
minimum
throw
true
throw
(b)
actual slip
Figure 8.14 Estimating throw on
a fault from known stratigraphy.
(a) Two units are juxtaposed across
a fault in the fi eld. (b) Possible
estimates of throw compared with
true throw. (c) Block diagram
representing theoretical situation if
no erosion had acted on the
faulted landscape.
true throw
(c)
8.3 Ductile structures: Shear zones,
foliations and folds
Ductile structures tend to form at depth in rocks which,
due to higher temperatures, can fl ow and buckle. Measuring
these structures provides information on deformation deep
in the crust and mantle, and stress regimes refl ecting the
large-scale tectonic forces that drive so much of the Earth
system.
8.3.1 Orientation of ductile planar features
Tectonic fabrics (foliations) can be found in discrete shear
zones (essentially, ductile faults), or they may occur
Search WWH ::




Custom Search