Abstract - The growth of normal faults in mechanically layered sequences is numerically modelled
using three-dimensional Distinct Element Method (DEM) models, in which rock comprises
an assemblage of bonded spherical particles. Faulting is induced by movement on a pre-defined
normal fault at the model base whilst a constant confining pressure is maintained by applying forces
to particles lying at the model top. The structure of the modelled fault zones and its dependency on
confining pressure, sequence (net:gross) and fault obliquity are assessed using various new techniques
that allow (a) visualization of faulted horizons, (b) quantification of throw partitioning
and (c) determination of the fault zone throw beyond which theoretical juxtaposition sealing occurs
along the entire zone length. The results indicate that fault zones become better localized with
increasing throw and confinement. The mechanical stratigraphy has a profound impact on fault
zone structure and localization: both low and high net:gross sequences lead to wide and relatively
poorly localized faults. Fault strands developing above oblique-slip normal faults form, on average,
normal to the greatest infinitesimal stretching direction in transtensional zones. The model results
are consistent with field observations and results from physical experiments.
In: The Geometry and Growth of Normal Faults. (Edited by Childs, C., Holdsworth, R. E., Jackson, C. A.-L., Manzocchi, T., Walsh, J. J. & Yielding, G.). Geological Society of London, Special Publication 439, doi.org/10.1144/SP439.17.