Page 173 - Fundamentals of Gas Shale Reservoirs

ThE ROlE OF TEcTOnIc AcTIVITIES On PORE PRESSuRE In ShAlES 153

0 1 2 3 4 5 6 7 8
E
Period Epoch Stratigraphic units Yilgarn craton
Lower permian Darling fault

Cainozoic Pre-Cambrian basement

Late Irwin terrace
Cretaceous Urella fault

Early

Parmelia group
Late Yarragadee Fm

Jurassic MID Cadda Fm

Cattamarra coal measures
Early Eneabba Fm Yarragardee Fm. Kockatea shale Dandaragan trough

Triassic Late M Lesueur Sst Cattamarra coal measures Eneabba Fm. Lesueur sandstone Upper permian Lower permian

Woodada Fm
Kockatea shale Cadda Fm. Woodada Fm. Pre-Cambrian basement
E
Beekeeper Dongara Sst Wagina Sst
Late Fm
Permian Early High cliff sandstone
Carynginia Fm
Holmwood shale
Nangetty Fm Mountain bridge fault
Carboniferous
Silurian
5 km Northampton uplift
Ordovician
Precambrian Basement W
0 1 2 3 4 5 6 7 8
FIGURE 7.16 northern onshore Perth Basin stratigraphy (left) and east–west structural section across the dandaragan Trough and adjacent
terraces (right). (Adapted from mory and lasky, 1996)

(King et al., 2008, Van Ruth et al., 2003). Regardless of the unlike many other basins around the world, stress orienta-
exact state of stress, most data suggest that the trajectory of tions in Perth Basin are not parallel to the direction of
the principal stress is in a horizontal plane and the main regional structure trends (hillis and Reynolds, 2000). Stress
direction of the principal stress axis (S hmax ) is largely oriented orientation in this part of the Australian continent is likely to
EW (Fig. 7.15). The orientation of principal stress is perpen- be induced by the forces exerted on the Indo‐Australian plate
dicular to the main north–south and northwest–southeast boundary and do not appear to be influenced by regional
faults trends and this trend is consistent throughout the basin. structure trends.