Figure 4
From: How transform fault shear influences where detachment faults form near mid-ocean ridges
Results for two different models with M = 0.6. Symbols are as defined in Fig. 3. (a)–(c) Model with the base friction angle of \(30^\circ\) everywhere. (a) Map of model topography at 3.0 Myr. The fault is located on the inside. Close to the transform fault, semi-permanent detachment faults lead to recurring inside corner-highs. (b) Plastic strain contours reveal faulting on the inside along the ridge segments. \(\sigma ^{'}_{xx}\) shows similar patterns and has similar causes (bending and shear on the TF) as the previous model with M = 0.75. (c) Far from the transform fault (y = 40 km, top), downward bending of the hanging wall lithosphere causes \(\sigma ^{'}_{xx}\) to be tensile near the top and compressive near the bottom of the lithosphere. Close to the TF (y = 10 km, bottom), \(\sigma ^{'}_{xx}\) is generally more tensile in the lithosphere on the inside corner and than on the outside corner. (d)–(f) Model with friction angle of \(3^\circ\) in FZs and TF. (d) Map of model topography at 2.0 Myr. The fault is located on the outside. Recurring detachment faults form close to the FZs on the outside. (e) Tensile stresses are elevated along ridge segments and in a very small region very close to the TF. (f) Vertical cross-sections of \(\sigma ^{'}_{xx}\) at 10 km from the TF. The stress field is very similar to (c) top, but reversed, left-to-right, indicating little or no perturbation of \(\sigma ^{'}_{xx}\) due to the (very weak) shear stress on the TF.
