Event UT4 was identified in Trench T4 at Tell Saidiyeh, a site situated along the Jordan Valley Fault. Unlike the purpose-excavated Trench T3, Trench T4 originated as a cut made during agricultural leveling works and trends northwest–southeast, oblique to the fault trace. The exposure was subsequently widened and cleaned by Ferry et al. (2011). The trench exposes a well-developed fault zone affecting both late Pleistocene and Holocene deposits. Because the trench is oriented approximately 45° to the fault, the deformation zone appears wider than in a perpendicular exposure and provides an unusually detailed record of repeated surface ruptures.
The evidence for Event UT4 is preserved along the same fault zone later reactivated during Event XT4, but approximately 0.8 m deeper within the trench section. According to Ferry et al. (2011:54-55), the faulting pattern at this depth is more complex and mature than that associated with younger events. The upper surface of unit k1 is strongly sheared and displays approximately 60 cm of cumulative offset, indicating that significant deformation had already accumulated along this part of the fault zone. Ferry et al. interpret this deformation as evidence that an earlier earthquake occurred after deposition of unit k1, prior to the later ruptures recognized higher in the section. The event is further constrained by the termination of several fault splays within the stratigraphic sequence. Faults associated with Event UT4 affect features correlated with the base of unit i2 and, in several cases, appear to terminate within unit i2 itself. Upward continuation of some splays cannot be traced with certainty and it remains unclear whether they also penetrate unit i1. Ferry et al. note that multiple splays terminate below the upper boundary of unit i2. This relationship indicates that Event UT4 occurred after deposition of unit i2 but before the younger units that seal the rupture.
The chronology of Event UT4 is constrained by the dated units that bracket the rupture horizon. According to Ferry et al. (2011:54), the observed stratigraphic relationships yield a broad occurrence window between approximately 11,600 BCE and 10,200 BCE. Considering the position of the event within the sequence and the geometry of the fault terminations, they also propose that the age range can be further constrained to between approximately 11,500 BCE and 10,500 BCE.
- Fig. 3b Location Map of the
Tell Saidiyeh Site from Ferry et al. (2011)
Geomorphology of the Tell Saidiyeh site from a high-resolution total station topographic survey (contour spacing 0.5 m). South of the archaeological tell (located ~100 m to the north; see inset in Fig. 8b), the morphology displays a recent terrace strath (Qto) affected and left-laterally displaced by the fault. The southern edges (dashed lines) of streams serve as piercing points because they are less likely to be eroded than the northern ones in a left-lateral setting. Stream El flows westward along the southern edge of Qto and is displaced by 7 ± 0.5 m across the fault. Stream W2 is a beheaded remnant of El and displays 114 ± 5 m of offset. A minimum emplacement age of 22 ka for W2 yields an average slip rate of 4.9 mm/yr for that period. Solid rectangles represent trenches T3 and T4, which display faulting evidence for the last 17 ka. Blanked areas could not be surveyed because of the presence of agricultural and military facilities.
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Ferry et al. (2011)- Fig. 5E Stratigraphic Correlation
between Ghor Khabed and Tell Saidiyeh Trenches from Ferry et al. (2011)
Correlations of stratigraphic sections of trenches. The geological formations of Lisan and Damya are common basement-bottom units for trenches. Erosion processes (tilde lines) have major effects on soft sediments, and Trench T3 shows a significant hiatus of the Damya formation. The correlation between alluvial and lacustrine deposits and the related radiocarbon dating (see also Table 1 and Fig. 7) illustrate the different recent depositional environments at trench sites.
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Ferry et al. (2011)- Table 1 Radiocarbon Table
from Ferry et al. (2011)
Radiocarbon Dating of Samples Collected in Trenches T1 and T2 (Ghor Kabed Site) and T3 and T4 (Tell Saidiyeh Site)
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Ferry et al. (2011)- Fig. 4a Oblique view of trench
T4 showing Lisan units affected by faulting and liquefaction from Ferry et al. (2011)
Oblique view of trench T4 showing Lisan units affected by faulting and liquefaction in the foreground and sand and silt units in the background
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Ferry et al. (2011)- Fig. 4b Main Shear Zone of trench
T4 from Ferry et al. (2011)
The main shear zone [of Trench T4) is outlined by a 1-cm-thick layer of crushed sand (thick lines) and displays numerous oriented pebbles.
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Ferry et al. (2011)Fig. 5d
Trench T4 is originally a road cut that was noticeably extended and cleaned. It is oriented 45° to the fault, which widens the deformation zone. This exposure provides the bulk of the paleoseismic dataset. See text for details.
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Ferry et al (2011)
