Inclined Shear (Restoration Menu)

• The inclined shear algorithm is most applicable to extensional tectonic regimes, where anticlinal rollover structures have developed on non-planer normal faults. Furthermore, this algorithm can be applied to the restoration or forward modelling of inverted basins and growth faults, where the thickness of beds may vary.

The inclined shear algorithm geometrically models the relationship between fault geometry and hangingwall deformational features. Inclined shear, models deformation where deformation is diffuse throughout the hangingwall rather than discrete slip between beds (i.e. flexural slip).

The inclined shear algorithm in 2DMove maintains the area between beds.

The deformation of the hangingwall is modelled by moving each point in the hangingwall by the same horizontal distance (the heave), following a path parallel to the fault. Each point on the hangingwall surface can be considered to be on a pin, which does not change its length as it is moved over the fault.

The Fault Parallel Flow (FPF)

• The FPF algorithm is best suited for modelling hangingwall movement on faults from fold and thrust belts where the majority of the deformation occurs discretely between bed interfaces (i.e. flexural slip).

The Fault Parallel Flow (FPF) algorithm, developed in collaboration with the University of Keele (Kane et. al, 1997 and Egan et. al, 1997), is designed to kinematically model geological structures in the hangingwall where deformation is accommodated by fault-parallel shear.

The Fault Parallel Flow toolbox uses an algorithm assuming particle flow parallel to the fault surface and parallel to the plane of cross section (plane strain assumption). Recent work has found that the Fault Parallel Flow algorithm may also be suitable for modelling in extensional regions.

Compared to geometric construction models for move on fault restorations like Flexural Slip, the Fault Parallel Flow algorithm is not restricted to simple ramp-flat-ramps with a dip less than 30°; thus, the Fault Parallel Flow algorithm may be applied to faults with a complex geometry.