The FMS images provide a good description of the fracturation in the basal dolerite of Hole 1109D but underestimate steep dips. The east-west strike of these fractures is compatible with the Woodlark Basin north-south extension, but their low dip is not.
The fracture zones observed in the northern margin sediment cores are not clearly visible on the FMS images, probably due to the lack of coverage of the tool pads. However the analysis of bedding orientations documents the association of bed deformation and faulting. The bed deformation can be caused by the fault movement or by gravity sliding along the depositional slope with small-scale growth faulting, roll-over folding, and slumping. These two processes are likely to produce similar structural axis orientations because the depositional slope is also controlled by the major normal faults.
Deformation seems to localize in a few lithologies. In particular, sands, which are poorly recovered, are often associated with deformation. Faulting in the sediments may therefore be more important than what was observed in core and on FMS. Tectonic studies of sedimentary sites may therefore require an electrical imaging tool with better borehole wall coverage, such as the Fullbore Formation MicroImager (FMI).