Portable OSL chrono-stratigraphic signatures at khirbet ‘Aujah el-Foqa: Implications for site formation processes

Khirbet ‘Aujah el-Foqa, located in the Jordan Valley, has been excavated since 2019. Excavations have revealed it is a fortified, multi-period site with remains from the Middle Bronze II, Iron Age II, and Ottoman Period. The formation of a hilltop desert khirbet, where pedosediment deposition and pre- to post-occupation processes differ from a settlement-layered tell, raises questions regarding stratigraphic structuring and chronological attribution. To address these challenges, an integrated methodology was applied, combining pottery typology, radiocarbon dating, and portable OSL chrono-stratigraphic signatures (PCSS). Rather than serving as independent absolute age determinations, portable OSL (pOSL) measurements were interpreted within securely defined archaeological contexts and used to refine relative chronological positioning and assess stratigraphic integrity. The results demonstrate distinct pOSL signal patterns corresponding to the site’s cultural periods, including evidence for single-period occupation surfaces, previously unidentified depositional units, and variable pedosediment accumulation. Mixed and intact deposits were differentiated based on signal behavior along vertical profiles. By embedding pOSL within a robust archaeological framework, this study presents a replicable and cost-effective chrono-stratigraphic approach that strengthens contextual attribution of pedosediments, detects disturbed and recycled deposits, and is readily transferable to other arid and semi-arid multi-period sites characterized by complex, pottery-poor stratigraphy.