Figure 3

Hypocentral cross-sections and inferred earthquake-fault association (Data from EQS- and MFS-Catalogs in this paper). (a) Map-view traces of 70 narrowly spaced radial cross-sections and six regional transects (A–F) used to build the 3D fault model. (b) Line-drawing of the near-vertical CROP-03 seismic reflection line across the northern sector of the ABT¹⁸; thrust numbered from 4 to 1 progressively rejuvenate in an age moving eastward from middle Miocene (thrust 4) to late Pliocene–Quaternary (thrust 1); T1 and T2 as in (c); (c) Section-view projection (within 20 km of the trace line) of earthquakes and focal mechanisms from this study (EQS- and FMS-Catalogs ), plus focal solutions in the 1967–2009 time interval from the literature^42,43 (e.g., yellow bordered circle). Key: black dots = Subset-1 data; grey dots = Subset-2 data; colored dots = focal mechanisms with kinematic color code as in Fig. 2b (Red = reverse, blue = normal, green = strike-slip, light yellow = unknown kinematics); green dots = strike-slip Family1 with SW–NE P-axes trending; green stars = strike-slip Family2 (deep-SS) with NNW–SSE P-axes trending; OEF = trace of Outcropping west-dipping Extensional Front. The yellow lines enveloping hypocenters and focal mechanisms offer a section view of the ABT (T1) and the underlying hidden lithospheric thrust identified in this paper (T2); the Moho depth line is from Di Stefano et al.⁶⁹. (d) Detail from transects E showing the intersection zone between T1 and T1-splay; the hypocenters from EQS-Catalog are projected with a half-width of 2.5 km.