REVIEW
A - Ramps and flats
B – Hangingwall ramp and
footwall ramp
C –? thrust sequence
New thrusts develop in the
footwall
D –? thrust sequence
New thrusts develop in the
Hangingwall
E – Structure of?:
imbricate thrust slices are
contained between a floor
thrust and a roof thrust
F - Pop-up structure
G – Triangle zone

Faults(4)
Extensional Fault System
Graben
Horst
half-graben
Listric Normal Fault
(‘listric means shaped like a spoon’)
A –Reverse drag B- Antithetic faults
Faulting above injection of igneous dikes
Extension by igneous dikes at depth,normal
faults in the upper crust.
Extensional Fault Systems
A- Evolutionary model illustrating
progressive extension accommodated
by block rotation above a low-angle
extensional fault,
B- Listric fault with hangingwall rollover
anticline,Area A and B are equal.
C – Flat/ramp geometry of fault produces
geometrically necessary folding in
hangingwall.
D- Antithetic faults in hangingwall.
E – Synthetic faults in footwall forming
listric fan.
F- Extensional duplex with listric fan and
antithetic counter fan.
G- Two listric faults linked by a transfer
fault;all three detach on the same sole fault.
Mylonite
（ H.Williams,1982）
A.,d＝ 5mm,B,d＝ 6mm
A- Gradational change
From unaltered rock on
The right,through
mylonite,to
ultramylonite on the left
In amphibolite.
× 14
C- Devitrified spherulitic
structure in
Pseudotachylite
× 250
Protomylonite
Grain ＞ 2mm,
Matrix 0～ 50
Protomylonite
PROBLEMS
? How is a rollover anticline formed?
? What is a detachment fault?
? What are the formation mechanism of
graben,half-graben?
? Is listric fault named from the shape?
? Distinguish between thrust duplex and
extensional duplex.