TY - JOUR
T1 - Revisiting radiocarbon dating of lime mortar and lime plaster from Jerash in Jordan
T2 - Sample preparation by stepwise injection of diluted phosphoric acid
AU - Daugbjerg, Thomas Schrøder
AU - Lichtenberger, Achim
AU - Lindroos, Alf
AU - Raja, Rubina
AU - Olsen, Jesper
N1 - Funding Information:
The work of the Danish-German Jerash Northwest Quarter Project was supported by the Carlsberg Foundation, the Danish National Research Foundation under the grant DNRF119 – Centre of Excellence for Urban Network Evolutions (UrbNet), Deutsche Forschungsgemeinschaft, Deutscher Palästina-Verein, the EliteForsk initiative of the Danish Ministry of Higher Education and Science and H. P. Hjerl Hansens Mindefondet for Dansk Palæstinaforskning. Thanks to Heikki Ranta for providing us the two samples from Dalby church.
Publisher Copyright:
© 2021 The Authors
PY - 2022/2
Y1 - 2022/2
N2 - Ancient Gerasa (its Greco-Roman name)/Islamic Jerash (its later Arab name) is one of the most well-known pre-modern urban sites in northern Jordan, which flourished throughout antiquity and into the early Islamic period. Direct dating of mortar and plaster in Jerash is challenging due to the area's abundance of geological carbonates that hamper the use of radiocarbon mortar methodologies as shown by previous attempts. Therefore, this study revisited the important problem of Jerash mortar dating. The aim was to advance solutions to the challenges with geological carbonates through sample pre-treatment and preparation methods such as wet sieving, sedimentation, cryo2sonic and stepwise injection of diluted acid. To characterize the samples we used alkalinity screening and cathodoluminescence microscopy. Ten plaster samples from an Umayyad house, destroyed by the earthquake in 749 CE, in Jerash were radiocarbon dated. These produced 12 conclusive dates out of 20 attempted datings, and here some samples had multiple attempted datings. These dates confirmed the early Islamic date of the house structure, while some samples suggested reuse of older material. Five comparative mortar samples from medieval Finland and Sweden critically evaluated the methodology proposed in this article. These have known ages, and they produced five conclusive dates that compared accurately with the expected ages. Compared to previous attempts at Jerash mortar dating, this study made substantial contributions to Jerash mortar dating.
AB - Ancient Gerasa (its Greco-Roman name)/Islamic Jerash (its later Arab name) is one of the most well-known pre-modern urban sites in northern Jordan, which flourished throughout antiquity and into the early Islamic period. Direct dating of mortar and plaster in Jerash is challenging due to the area's abundance of geological carbonates that hamper the use of radiocarbon mortar methodologies as shown by previous attempts. Therefore, this study revisited the important problem of Jerash mortar dating. The aim was to advance solutions to the challenges with geological carbonates through sample pre-treatment and preparation methods such as wet sieving, sedimentation, cryo2sonic and stepwise injection of diluted acid. To characterize the samples we used alkalinity screening and cathodoluminescence microscopy. Ten plaster samples from an Umayyad house, destroyed by the earthquake in 749 CE, in Jerash were radiocarbon dated. These produced 12 conclusive dates out of 20 attempted datings, and here some samples had multiple attempted datings. These dates confirmed the early Islamic date of the house structure, while some samples suggested reuse of older material. Five comparative mortar samples from medieval Finland and Sweden critically evaluated the methodology proposed in this article. These have known ages, and they produced five conclusive dates that compared accurately with the expected ages. Compared to previous attempts at Jerash mortar dating, this study made substantial contributions to Jerash mortar dating.
KW - Cathodoluminescence
KW - Jerash
KW - Mortar dating
KW - Plaster dating
KW - Radiocarbon dating
KW - Stepwise injection
UR - http://www.scopus.com/inward/record.url?scp=85120938780&partnerID=8YFLogxK
U2 - 10.1016/j.jasrep.2021.103244
DO - 10.1016/j.jasrep.2021.103244
M3 - Article
AN - SCOPUS:85120938780
SN - 2352-409X
VL - 41
JO - Journal of archaeological science: Reports
JF - Journal of archaeological science: Reports
M1 - 103244
ER -