Abstract - The boundaries between pairs of adjacent fault segments within normal fault arrays
define a spectrum of structures, from relay ramps where the length of overlap between the fault
segments is much larger than the separation, through low aspect ratio (overlap/separation) relay
ramps and ultimately to underlapping fault segments. Where fault segments underlap, transfer
of displacement between them is accommodated by a connecting monocline. When displacement
increases and a through-going fault forms, relay ramps are preserved as fault-bounded zones of elevated
bed dip and monoclines are preserved as areas of normal drag. Therefore, the orientation and
magnitude of bed dips within and adjacent to a fault zone, and the numbers of segments seen on a
cross-section through it, depend largely on the aspect ratios of relay ramps in the initial fault array.
The aspect ratio of relay ramps varies between different fault systems. An analysis of the geometry
of 512 relay ramps from 13 different fault systems suggests that the main controls on aspect ratio
are the strength of the sequence at the time of faulting and the underlying structure.
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/SP439.16.