At the Balkar Trench T2, excavated in the northeastern part of the Pazarcık segment of the East Anatolian Fault, Yönlü and Karabacak (2023:4) identified Event X as a distinct surface-rupturing earthquake recorded by displacement within the trench stratigraphy. The event postdates Unit 20 and predates Unit 22, establishing its position within the sequence.

A radiocarbon sample from Unit 20 (Poz-45673) yielded a calibrated age range of 811–401 BCE ( 2σ), while a sample (Poz-45672) from Unit 23, higher up in the section, produced a calibrated age of 990–1390 CE (2σ). These two samples constrain Event X to a terminus post quem of 811–401 BCE and a terminus ante quem of 990–1390 CE. However, a radiocarbon sample taken from within Event X fault gouge (Poz-45684) yielded a calibrated age of 841–451 BCE (2σ) which provides a tighter constraint, suggesting that Event X most likely occurred between 841 and 451 BCE.

Yönlü and Karabacak (2023:4) further note that motion in Balkar Trench T2 during this event involved dominant strike-slip movement with a reverse (compressional) component, indicating oblique-slip deformation along the fault.

Figure 4b - Trench Log of SW wall of Balkar trench - Thin black lines are stratigraphic contacts - colours show units - red lines are traces of faults - small rounded outlines are gravels - (trench location 374 154 m E/417 775 m N) - Yönlü and Karabacak (2023)