EXAMINING THE ARCHAEOSEISMIC ACTIVITY OF THE ARCHAEOLOGICAL SITE OF SARDIS IN WESTERN TURKEY USING OPTICALLY STIMULATED LUMINESCENCE DATING

The ancient city of Sardis was built across active faults along the southern boundary of the normal fault system that defines the Gediz Graben. Having been occupied since late 3^rd to early 2^nd millennia BCE the site contains remnants of many different cultures. Some structures show evidence of damage caused by earthquakes, but little research has been conducted in identifying individual seismic events. The focus of this study is to document paleoearthquakes at the archaeological site of Sardis and compare these with data collected from trenches excavated across the active fault located away from the site. Two paleoseismic trenches were excavated across a large fault scarp that separates Holocene and historical sediment from the mountain range that is mapped as Plio-Quaternary clastic rocks located off the archeological site. In these trenches evidence for several ancient earthquakes were documented based on colluvium wedge developments along three different faults. In addition to these obvious paleoseismic structures, the trenches included channel deposition representing at least three different events of increased velocity possibly caused by the downward movement of these normal faults. Organic material was collected from both trenches for radiocarbon analyses to help constrain the timing of the paleoearthquakes. Furthermore, a trench was excavated on the archaeological site of Sardis where members of the Archaeological Exploration of Sardis, sponsored by the Harvard Art Museums and Cornell University, re-exposed a trench in Field 55 that contained three open fissures that terminate 1.25 m below the ground surface. Ceramic dating suggests that the fissures were buried post-7th century CE. In order to refine the timing of the paleoearthquakes radiocarbon samples collected at the offset and capping layers of these fissures. However these samples were miniscule and scarce. Therefore optically stimulated luminescence (OSL) samples were collected from the same layers. With the assistance of Joel Q.G. Spencer, Ph.D. from Kansas State University, the OSL analysis will help constrain the timing of the paleoearthquakes.