Abstract - The growth of normal fault arrays is examined in basins where sedimentation rates were higher than fault displacement rates and where fault growth histories are recorded by thickness and displacement variations within syn-faulting sequences. Progressive strain localisation is the principal feature of the growth history of normal faults for study areas from the Inner Moray Firth, a sub-basin of the North Sea, and from the Timor Sea, offshore Australia. The kinematics of faulting is similar in both study areas. Fault displacement rates correlate with fault size, where size is measured in terms of either displacement or length. Small faults have higher mortality rates than larger faults throughout the growth of the fault system. Displacement and strain are progressively localised onto the larger faults at the expense of smaller faults at progressively larger scales. Strain localisation and the preferential growth of larger faults are attributed to geometric factors rather than to the mechanical properties of fault rock in individual faults. This conclusion is supported by numerical models that reproduce the main characteristics of fault system growth established from both study areas.
The nature of the tectonic significance of fault zone weakening. Geological Society of London, Special Publication, 186, 157-170, 2001.