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Structural geology. Structure. Ductile deformation Fold Foliation Lineation etc. Brittle deformation Joint Tension gash Styloite Fault etc. Fault. Reconstruction of regional stress. Fault surfaces displaying the direction of slip lineation. pitch. pitch. - PowerPoint PPT Presentation
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Brittle deformation
JointTension gashStyloiteFault etc..
Reconstruction of regional stress
Structural geology
Structure
Ductile deformation
FoldFoliationLineation etc.. Fault
Fault surfaces displaying the direction of slip lineation
Stereographic projection of a fault slip data set
Lower hemisphere project
Fault plane
Slickensidelineation
pitch
Fault plane
pitch
Method of right dihedrons
obtaining the orientationof principal stress axesfrom statistic method
S’/S = f (inclination)
STEREOGRAPHIC NET
S’/S = const.
Wuff net Schmidt net
Wuff net (equiangular)
OPM isosceles triangle
ON/OP = tan (/4-i/2)
ON = R tan (/4-i/2)
Schmidt net (equal-area)
ON = OX, OX = (2)1/2 OH
OH/OP = sin (/4-i/2)
ON = (2)1/2 R sin (/4-i/2)
3D inversion of field data in fault tectonics
Eigenvalues and eigenvectors of T give the orientation of principal stress axes (1 ,
2 and 3), as well as the shape ratio of the stress ellipsoid ( = (2-3)/(1-3)).
(e.g., Angelier, 1979, 1984, 1989, 1990)
Field measured data Computed stress axes Theoretical fault shears
Inversion result
(Angelier, 1990)
(Chang C. P., Unpubl.)
Example from the seismic focal mechanism
= (2-3)/(1-3)
0 reverse and strike-slip
1 normal and strike-slip
0 1
case 1
case 2
case 1
case 2
(Kao and Jian, 2001)
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