a
c
Antithetic
shear
Secondary
synthetic
shear
Synthetic
shear
Master
fault
Extension
fracture
En echelon
folds
b
Riedel (R)
shear
Conjugate
Riedel (R’) shear
Y shear
Tension (T)
fracture
P shear
Fig. 12.13 (a–b) Fracture types typical for a dextral strike-slip
system. By advanced stages of strain, synthetic shears (Riedel
shears) and fractures associated with the master fault (Y-shears)
tend to dominate the geometry of the fault zone. (c) Most
common hydrocarbon traps in strike-slip systems. Types of
structures are indicated in the figure. (a) and (b) are redrafted
from Crowell (1974)
12 The Structure and Hydrocarbon Traps of Sedimentary Basins
339