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 – Thrust duplex:
imbricate thrust slices are
contained between a floor
thrust and a roof thrust
F - Pop-up structure
G – Triangle zone
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.
Strike-slip fault system
A- Local compressional
and extensional struc-
tures produced by fault
terminations and fault
overlaps.
B-Formation of raised
and depressed wedge-
shaped blocks by local
transpression and
transtension.
C- Positive and negative
flower structures produ-
ced by convergence and
divergence respectively
in strike-slip motion
D-Strike-slip duplex
Lecture 11 Invension and Joints
Lecture 11 Inversion and Joints
Lecture Outline
1) Inversion
2) Definition of
fracturing,joints,
faults and veins
3) Joint patterns
4) Joint surface
5) Joint statistics
Inversion,extensional half-graben reactivated in
compression.
Note that compressional folds coexisit with net normal
displacement
FRACTURING:
1) Rupture – loss of cohesion,breaking of bonds
2) Displacement
a) No sliding – Joint
b) Sliding – Fault
c) Cemented & filled by minerals - Vein
Jointing Faulting
Veining
EXTENSION JOINTS,LIMESTONE & SANDSTONE
VEINS,EVIDENCE FOR FLUID FLOW
Rupture Modes,A,Mode I,Extension,B,Mode II,In-plane shear normal to tip
line,Mode III,In-plane shear parallel to tip line,(Almost all natural fractures are
‘mixed mode’.)
A,Mode I opening B,Mode II sliding C,Mode III tearing
RUPTURING – IDEAL MODES OF
RUPTURE PROPAGATION
Relationship of joint sets to a major fold
a.longitudinal joints,b.diagonal joints,
c.transverse joints,d.sheet joints
Fold axis
d
FRACTURE PATTERNS IN FOLDS
(VERY SIMPLIFIED)
After Twiss and Moores,1992)
Joints patterns developed in a pluton
Q.Transverse joints,S.Longitudinal joints,
L.Sheet joints,D.Diagonal joints,F.Flow lines
Two sets of conjugate joints developed in Cretaceous
sandstone,Chucheng,Shandong Provience
En echelon joints developed in limestone,Tuoli,
Beijing.Note the left-lateral (right-step type) and
right-lateral-lateral (left-step type) joint patterns
En echelon tension joints (a) and shear joints (b)
developed in Upper Devonian Limestone in Xikuangshan,
Hunan Province
Elements of an en echelon joint system:
aa'-bb'.en echelon zone,MM‘en echelon axis,βen
echelon angle,AW,Width of the en echelon zone
Detail of plume structure on joint
surface（ After Bankwitz,1966）
Main joint face
Plume axis
fringe
Fringe joints
step
SURFACE MARKS
RECORD HISTORY OF
FRACTURE GROWTH
(Key to forensic structural geology)
Formation of columnar joints
Formation of hexagonal cooling joints (columnar
structure) that form around uniformly distributed
centers of contraction.Arrows indicate orientations of
tensile stresses (After Hatcher R.D.,1995)
Plume-rib compound structure on joint surface in
Triassic tuff limestone,Western Mountains,Beijing
Plume axis
Fringe zonePlume veins
step
Fringe face
Plume-rib compound
Structure by modeling
(Zuoxun Zeng and
Lilin Liu,1992)
Plume mark in slate in Hunan
Plume mark in Quartzite
in Henan
Plume mark in crystal tuff
in Hujian
Biplume structure on fracture surface in
a gelatin model (Zeng and Liu,1992)
Furcate plume structure on the fracture surface
developed in a gelatin plate model
Rib mark in rocks
Rib mark in model
Half-plume mark in rock
Isochromatic fringe pattern
Rib and plume marks in model
Plume mark on fracture surface (a)
and the trace of the fracteuesurface(b)
JOINT PATTERNS
Key Words,Set,Systematic,Nonsystematic,
Joint Zones
(After Twiss and Moores,1992)
Single Set
Multiple Sets
Jointing Controls Landscape
Evolution
(regional joint sets – rock
strength,groundwater flow)
FRACTURE PATTERNS IN FAULT ZONES
(Very Simplified)
After Twiss & Moores
(1992)
Joint statistics
? Joint frequence
? Joint density
References
? Zuoxun Zeng,and Lilin Liu,Theoretical and
experimental researches on plume and rib
structures,Earth Science--Journal of China
University of Geosciences,1994,19(5),647--654,
? Zuoxun Zeng,An experimental research on
conjugate shear angles,Geological Science and
Technology Information,1991,10(4),45--49.
? Zuoxun Zeng and Lilin Liu,Tectonic Modeling,
China University of Geosciences Press,1992.
Summary
? Inversion,Positive inversion,Negative
inversion
? Joint,joint pattern,conjugate joints,en
echelon joints
? Joint surface,plume structure,rib structure
and plume-rib compound structure,
monoplume structure,biplume structure,half-
plume structure and furcate plume structure
Joint statistics
Problems
? How to distinguish between positive and negative
inversion?
? Could you distinguish a joint from a fault and a vein?
? What are the significance of joints?
? Analyze the formation of different joint patterns.
? Analyze the formation of different joint surface
structures
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 – Thrust duplex:
imbricate thrust slices are
contained between a floor
thrust and a roof thrust
F - Pop-up structure
G – Triangle zone
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.
Strike-slip fault system
A- Local compressional
and extensional struc-
tures produced by fault
terminations and fault
overlaps.
B-Formation of raised
and depressed wedge-
shaped blocks by local
transpression and
transtension.
C- Positive and negative
flower structures produ-
ced by convergence and
divergence respectively
in strike-slip motion
D-Strike-slip duplex
Lecture 11 Invension and Joints
Lecture 11 Inversion and Joints
Lecture Outline
1) Inversion
2) Definition of
fracturing,joints,
faults and veins
3) Joint patterns
4) Joint surface
5) Joint statistics
Inversion,extensional half-graben reactivated in
compression.
Note that compressional folds coexisit with net normal
displacement
FRACTURING:
1) Rupture – loss of cohesion,breaking of bonds
2) Displacement
a) No sliding – Joint
b) Sliding – Fault
c) Cemented & filled by minerals - Vein
Jointing Faulting
Veining
EXTENSION JOINTS,LIMESTONE & SANDSTONE
VEINS,EVIDENCE FOR FLUID FLOW
Rupture Modes,A,Mode I,Extension,B,Mode II,In-plane shear normal to tip
line,Mode III,In-plane shear parallel to tip line,(Almost all natural fractures are
‘mixed mode’.)
A,Mode I opening B,Mode II sliding C,Mode III tearing
RUPTURING – IDEAL MODES OF
RUPTURE PROPAGATION
Relationship of joint sets to a major fold
a.longitudinal joints,b.diagonal joints,
c.transverse joints,d.sheet joints
Fold axis
d
FRACTURE PATTERNS IN FOLDS
(VERY SIMPLIFIED)
After Twiss and Moores,1992)
Joints patterns developed in a pluton
Q.Transverse joints,S.Longitudinal joints,
L.Sheet joints,D.Diagonal joints,F.Flow lines
Two sets of conjugate joints developed in Cretaceous
sandstone,Chucheng,Shandong Provience
En echelon joints developed in limestone,Tuoli,
Beijing.Note the left-lateral (right-step type) and
right-lateral-lateral (left-step type) joint patterns
En echelon tension joints (a) and shear joints (b)
developed in Upper Devonian Limestone in Xikuangshan,
Hunan Province
Elements of an en echelon joint system:
aa'-bb'.en echelon zone,MM‘en echelon axis,βen
echelon angle,AW,Width of the en echelon zone
Detail of plume structure on joint
surface（ After Bankwitz,1966）
Main joint face
Plume axis
fringe
Fringe joints
step
SURFACE MARKS
RECORD HISTORY OF
FRACTURE GROWTH
(Key to forensic structural geology)
Formation of columnar joints
Formation of hexagonal cooling joints (columnar
structure) that form around uniformly distributed
centers of contraction.Arrows indicate orientations of
tensile stresses (After Hatcher R.D.,1995)
Plume-rib compound structure on joint surface in
Triassic tuff limestone,Western Mountains,Beijing
Plume axis
Fringe zonePlume veins
step
Fringe face
Plume-rib compound
Structure by modeling
(Zuoxun Zeng and
Lilin Liu,1992)
Plume mark in slate in Hunan
Plume mark in Quartzite
in Henan
Plume mark in crystal tuff
in Hujian
Biplume structure on fracture surface in
a gelatin model (Zeng and Liu,1992)
Furcate plume structure on the fracture surface
developed in a gelatin plate model
Rib mark in rocks
Rib mark in model
Half-plume mark in rock
Isochromatic fringe pattern
Rib and plume marks in model
Plume mark on fracture surface (a)
and the trace of the fracteuesurface(b)
JOINT PATTERNS
Key Words,Set,Systematic,Nonsystematic,
Joint Zones
(After Twiss and Moores,1992)
Single Set
Multiple Sets
Jointing Controls Landscape
Evolution
(regional joint sets – rock
strength,groundwater flow)
FRACTURE PATTERNS IN FAULT ZONES
(Very Simplified)
After Twiss & Moores
(1992)
Joint statistics
? Joint frequence
? Joint density
References
? Zuoxun Zeng,and Lilin Liu,Theoretical and
experimental researches on plume and rib
structures,Earth Science--Journal of China
University of Geosciences,1994,19(5),647--654,
? Zuoxun Zeng,An experimental research on
conjugate shear angles,Geological Science and
Technology Information,1991,10(4),45--49.
? Zuoxun Zeng and Lilin Liu,Tectonic Modeling,
China University of Geosciences Press,1992.
Summary
? Inversion,Positive inversion,Negative
inversion
? Joint,joint pattern,conjugate joints,en
echelon joints
? Joint surface,plume structure,rib structure
and plume-rib compound structure,
monoplume structure,biplume structure,half-
plume structure and furcate plume structure
Joint statistics
Problems
? How to distinguish between positive and negative
inversion?
? Could you distinguish a joint from a fault and a vein?
? What are the significance of joints?
? Analyze the formation of different joint patterns.
? Analyze the formation of different joint surface
structures
