Kinematic analyses of brittle roto-translational planar and listric faults based on various rotational to translational velocities of the faulted blocks

Abstract

Research on rotational/roto-translational faults have been relatively less than translational faults. This is despite perfect translational faults seldom occur in mega-scale. This work models slickenside lineation patterns on planar and listric fault planes for different ratios of rates of rotation to the uniform speed towards a specific geographic direction (“ω/v”) of faulted blocks. Curves simulated for the planar fault planes are fitted with natural examples of such roto-translational faults. In our 10 chosen examples, the “ω/v” ratio ranges between 0.2 (fault at San Miguelito range, Central México) and as high as 2.4 (fault at Hyogoken-Nambu, Japan). Knowing the “ω/v” ratios from terrains can better interpret its tectonics, For example, if “v” and the total time of duration of the deformation are known from some other studies, even the total amount of rotation can be estimated. The far-reaching implication of this study is that, as several hydrocarbon reserves and terrains with landslides are related to roto-translational faults, this work will be a stepping-stone in petroleum geosciences (e.g., stability of hydercarbon reserve) and engineering geology (e.g., stability of slope).