COMPARISON OF EARTHQUAKE-DAMAGED WATERWORKS STRUCTURES OF ROMAN TO ISLAMIC AGE AT QASR TILAH, JORDAN

The Qasr Tilah archaeological site is located on the Wadi Araba fault portion of the Dead Sea transform in Jordan. This fault system has experienced several major damaging earthquakes including those of 363 A.D. and 1068 A.D. Archaeological excavations and architectural survey of the Qasr Tilah site were conducted in May 1999, May 2001, January 2003, and July 2003 as part of the Wadi Araba Earthquake Project. The main objectives of excavation were to date the timing and assess the magnitude of earthquakes that have impacted the site. This study focuses on defining the construction periods of the aqueducts and water reservoir system at Qasr Tilah, Jordan. Several aqueducts of various constructions and elevations lie parallel to the course of the Wadi Tilah. The oldest aqueduct, Phase I, is cut into the bedrock and is plastered in the channel and on the outer wall. This type of construction is suggestive of technologies of the Nabataeans (1st Century B.C-2nd Century A.D.). The Phase II aqueduct appears to be a widening of the older aqueduct at the same elevation although evidence for this phase is spotty. The upper Phase III aqueduct is approximately 1.9 m above the Phase I aqueduct channel floor. It is constructed of large undressed boulders of local limestone with mortar and cobbles used as chinking blocks. It is also plastered. The characteristics of this aqueduct are the same as those observed in the sections at the water reservoir, which has been radiocarbon dated to ca. 641-687 A.D. The Phase III aqueduct connects to the water reservoir through a vertical outflow channel flowing from the top of the reservoir and a settling pool at the base of the reservoir. X-ray diffraction analyses of mortar and plaster samples collected from the various aqueducts do not reveal any discernable difference in construction materials. Analyses of thin sections from the mortar and plaster samples is underway. The aqueduct systems and reservoir at Qasr Tilah have clearly been disrupted by several earthquake faulting events when the system was still functioning and after it had been filled with sediment.