The white marbles and polychrome stones of the five-aisled basilica at Gadara (Umm Qais), Jordan: archaeometric characterization for provenance identification

This research sheds light on the use of white marble and polychrome stones in building the five-aisled basilica at Gadara (Umm Qais), north Jordan. The research uses different analytical techniques to investigate the physical, mineralogical, chemical, and isotopic properties of 24 marble elements aiming at the identification of their provenance. The basilica was likely built in the 4 th c. AD, renovated by an addition of a new mosaic floor in the early of the 6 th c. AD, reduced to a chapel in the 8 th c. AD, and converted into a mosque during the Ayyubid-Mamluk periods. The results showed three sources of the white marble: the Thasian-3 from Cape Vathy, Thasos Island, Greece; the Proconnesian from Saraylar and Kavala (Proconnesian-1) and Çamlik (Proconnesian-2), Marmara Island, Turkey; and the Parian-2 from Lakkoi, Chorodaki valley, Paros Island, Greece. The results show the use of four well-known varieties of polychrome stones which were widely used by the Romans in antiquity: Marmor Sagarium / Breccia Corallina , Marmor Troadense / Granito Violetto , Marmor Styrium / Cipollino Verde , and Marmor Pavonazzetto . These results attest the prosperity and the major development of Gadara during the 4 th c. AD, and indicate its wide trade connections to import such a combination of building stones for different functions. The results support previous studies that showed the dominant use of Proconnesian marble at Gadara during the Byzantine period, and present new evidence of use of new polychrome stone varieties in the decoration of Gadara’s structures.