Lateral and vertical pulsed-photon portable luminescence (PPSL) profiling of anthropogenically-altered sediments in rescue excavations of different landscapes

Growing infrastructure development in Israel has increased the number of rescue excavations involving multi-layer archaeological sites and "megasites" in landscapes ranging from dunes to clay-rich soils and yielding prehistoric to early modern finds. The limited time and resources allocated for the excavations requires rapid on-site scientific data, which are used for research during and after excavation, prioritizing artefact treatment, sediment analysis, and absolute and relative dating.

Lateral and vertical pulsed-photon (portable) OSL (PPSL) profiling of sections of anthropogenically-altered sediments containing feldspar or quartz, provide rapid and partial answers for interpreting depositional processes. These answers allow researchers to discriminate between natural and human-intervened sedimentation, identify relative age and laterally synchronize between similar sediment units, which, in turn, often help to orient the excavation goals. The potential for inhomogeneity of archaeological sediments in some cases constrain the comparability of results and call for complementary analysis of the measured sediments in order to define their inter-compatibility. Independent mineralogical and chemical and textural properties of the sediments affect the inherent luminescence signals and should therefore be analyzed.

Here we present a PPSL profiling approach combining tailored sedimentological analyses to validate sample comparability in different sedimentological and archaeological settings. The analyses include gamma and FTIR spectroscopy, portable XRF geochemistry, carbon content, particle-size distribution and colorimetry. The complementary data are intended to improve PPSL protocols by characterizing the context inhomogeneity and helping to prioritize samples for OSL dating