Abstract - The lack of an unambiguous method of determining the propagation direction of slip events on faults over
significant time periods limits our understanding of the long-term stability of fault slip propagation directions. A geological
means for determining the propagation direction of slip events during the growth of faults is provided by mutually cross-cutting
faults and bed-parallel slip-surfaces in the Ptolemais Basin, northern Greece. Bed-parallel slip-surfaces intermittently offset
the faults as they grew to form discontinuities on otherwise continuous fault surfaces. Subsequent fault slip events bypassed
these discontinuities generating structures that provide a record of their propagation direction. Data collated from 3D fault
mapping during lignite mining operations reveal that the slip events on these faults propagated predominantly upwards at low throws.
Mixed slip propagation directions at higher fault displacements, up to 50 m, demonstrate that the locations of the points of
nucleation of slip events were more distributed over fault surfaces once the faults were established.
Tectonophysics, 774, 228296, doi: https://doi.org/10.1016/j.tecto.2019.228296, 2020.