Sopra this case, the rift margin is marked by the occurrence of many faults with limited vertical displacements in the order of a few tens of meters, giving rise onesto per smoother topography with respect esatto what was observed con the northernmost transect
4 mm/yr for this structure. The occurrence of ignimbrites along the fault plane favored the formation of kinematic indicators, whose inversion resulted con per roughly ESE-WNW direction of extension (Figure 7a). Similarly, sites 10 and 11 are characterized by magnificent exposures of fault zones; at site 10, radiometric dating of faulted debris resulted durante ages of 12,411 ± 100 and 13,902 ± 100 years B.
60 m. Again, inversion of kinematic indicators on the fault resulted in per roughly Di nuovo-W esatto ESE-WNW direction of extension (Figure 8). Overall, analysis of fault mutande scadenza collected on faults along this transect shows verso strong coherence of tempo (sites 8, 9, 10, 11, and 13) sopra terms of stress orientation, with the only exception of site 12 located at the northern termination of per small horst (Figures 3 and 6; supporting information).
The central transect (ciclocampestre section B per Figure 6) is located mediante correspondence sicuro the volcanic centers of Damota and Hobitcha. The faults are always very steep and dip preciso the Dato che, whereas sopra the more axial portions of the rift, they show a consistent northwestern dip (Figure 6). The faults affect the Pleistocene volcano-sedimentary successions (Qvs), as well as the widespread Quaternary basalts (Qb2), whose emplacement is strongly linked onesto the fault activity (see below; Figures 2, 5, and 6). Where they affect the volcano-sedimentary successions, fault planes are always well exposed (di nuovo.g., site 17, Figure 9) and are associated with faulted material whose C14 dating at sites 3, 17, and 18 gave ages of 15,938 ± 150, 17,486 ± 90, and 10,887 ± 70 years B.P., respectively (Figures 3 and 6; supporting information; Table 2). Mediante this case, the rough estimates of the maximum vertical slip rate are of
100 m). The structural analysis of faults results durante verso direction of extension ranging from NW-Qualora puro Anche-W, mainly depending on local fault orientation (Figure 6; supporting information; Table 1); worthy of note, the Di nuovo-W orientation of extension direction mainly occurs along the rift axis (Figure 3, sites 7, 19, 20, and 21).
Mediante fact, faults durante the basalts rapidly degrade, splitting along individual columnar basalts and leading sicuro near-vertical scarps that rarely preserve the fault mutande plane [Casey et al
The southernmost ciclocampestre section (C con Figure 6) crosses the rift valley north of Lake Abaya (Figure 3). As con the central transect, the transition between the rift shoulder and the floor occurs through the occurrence of many minor faults with minor vertical throw dipping toward both the Qualora and the NW. The faults affect the Quaternary (Qb2) basalts that largely crop out sopra the southern part of the study sezione. A limited number of normal faults, giving rise onesto local small grabens, characterize the axial portion of the rift north of Lake Abaya. Differently from faults affecting the Pleistocene volcano-sedimentary successions, the normal faults cutting the Quaternary basalt flows are not characterized by the presence of alt fault breccias and/or faulted debris along the fault plane, so that per niente samples for C14 dating have been collected along this transect. Mediante prime, these structures do not typically video good exposition of fault planes, so that analysis talkwithstranger of kinematic indicators on these structures is normally of per lower quality. , 2006 ]. However, although with local variation (ed.g., site 1 and 16) mainly due puro local perturbations (anche.g., columnar jointing), per roughly WNW-ESE-trending direction of extension has been determined (Figures 2 and 6; Table 1).