REGIONAL STRESS REGIMES
AND CHINA TECTONICS
REGIONAL STRESS REGIMES
(ANDERSON THEORY OF FAULTING)
? [s2 is located parallel to the fault plane,normal to the
direction of slip]
[ s3 is located normal to s1 and s2 ]
? Earth’s surface is a principal plane of stress
? Ideal fault geometry
? 3 stress regimes,Normal,Thrust,Strike-slip
Fault orientation in relation to principal stress axes
(After E.M.Anderson,1951)
A Normal fault sets,B Thrust fault sets,C Strike-slip fault sets
Distribution of potential faults from uniform
compressive stresses at two ends(After W.Hafner,1951)
1.Stress 2.Trajectories of maximum principal stress 3.Trajectories of
minimum principal stress 4.Potential fault
Distribution of potential faults result from non-uniform
boundary stress (After W.Hafner,1951)
High Friction Low Friction
Convergent Margin
‘Mega-thrust’
The Velocities of the Tectonic Plates
with
respect to the Earth’s center
Plate 1
Plate 2
V1
V2
RMV
Fix Plate 1 by subtracting V1
from itself,Then must also
subtract V1 from V2,The
result is the relative motion
vector of plate 2 with respect
to plate 1.
CALCULATE RELATIVE MOTION VECTOR
FROM ABSOLUTE PLATE VELOCITIES
Normal Faulting Regime
Reverse Faulting Regime
s1
s1
s3
s3
s2
s2
s2 & s3 are horizontal,
s1 is vertical
s1 & s2 are horizontal,
s3 is vertical
STRIKE – SLIP FAULTING REGIME
s1
s3
s2
Map
view
s1 & s3 are horizontal,
s2 is vertical
TECTONICS OF CHINA
(TIAN SHAN LABORATORY)
Tian Shan
Kunlun Shan
India
Tibet
Tarim Basin
Tarim Basin
Tian Shan
Pik Pobeda
(Sheng-li Feng
GPS Survey,Tibet,Tarim Basin,Tian Shan