Figure 3
From: How transform fault shear influences where detachment faults form near mid-ocean ridges
Model results for base model with M = 0.75 are shown. For visualization, the images are restricted to +/–60 km in x and y. (a) Map view of model topography at 2.0 Myr, showing transient faulting on both sides of the ridge axis creating abyssal hill-like topography. Black solid and dashed rectangles outline the transform fault and fracture zones, respectively. White lines mark dike injection zones. Yellow lines mark fault breakaways (i.e., where the fault scarp was first exposed) and grey lines mark fault terminations. A pair of inside and outside corners is marked with IC and OC, respectively. (b) Map view of deviatoric horizontal normal stress (\(\sigma ^{'}_{xx}\), positive for tension) averaged in depth between the seafloor and the 600 °C-isotherm. Black solid and black dotted contours show accumulated plastic strain of 0.2 and 1.2, respectively, revealing active faulting on the fracture zone-side far from the transform fault and on the inside corner near the transform fault. \(\sigma ^{'}_{xx}\) is tensile along the ridge segments and most tensile in a broad area on either side of the transform fault. (c) Vertical cross-sections of \(\sigma ^{'}_{xx}\) at y = 40 km and y = 10 km (located by black lines in panel b). Red triangles locate the dike zone, black contours are as in (b), and white line marks the 600 °C-isotherm. At a distance of y = 40 km from the transform fault (c 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 transform fault (y = 10 km, c bottom), \(\sigma ^{'}_{xx}\) is generally more tensile in the deeper part of the lithosphere attached to the footwall than in the hanging wall.
