Mechanics of evenly spaced strike-slip faults and its implications for the formation of tiger-stripe fractures on Saturn's moon Enceladus

We present the first mechanical analysis based on realistic rheology and boundary conditions on the formation of evenly spaced strike-slip faults. Two quantitative models employing the stress-shadow concept, widely used for explaining extensional-joint spacing, are proposed in this study: (1) an empirically based stress-rise-function model that simulates the brittle-deformation process during the formation of evenly spaced parallel strike-slip faults, and (2) an elastic plate model that relates fault spacing to the thickness of the fault-hosting elastic medium. When applying the models for the initiation and development of the tiger-stripe fractures (TSF) in the South Polar Terrain (SPT) of Enceladus, the mutually consistent solutions of the two models, as constrained by the mean spacing of the TSF at similar to 35 km, requires that the brittle ice-shell thickness be similar to 30 km, the elastic thickness be similar to 0.7 km, and the cohesive strength of the SPT ice shell be similar to 30 kPa. However, if the brittle and elastic models are decoupled and if the ice-shell cohesive strength is on the order of similar to 1 MPa, the brittle ice shell would be on the order of similar to 10 km. (c) 2015 Elsevier Inc. All rights reserved.