Our laboraroty is developing new techniques for application to the dating of artefacts and deposits from sites that range widely in terms of chronological period, geographic location and material type. Recent work as focused on optically stimulated luminescence (OSL) techniques, in particular a novel experimental approach to the measurement of single grain OSL.
We have been at the forefront of applying luminescence dating to brick from medieval buildings in England and this work has also included the dating of brick from medieval buildings in NW France with the University of Bordeaux III as part of a CNRS-funded GdRE network Ceramic Building Materials and New Dating Methods. A study produced, for the first time, absolute dates for a range of brick stupas located within the hinterland of Anuradhapura (Sri Lanka), contributing to the further development of a brick monument chronology for the region. Ongoing work is examining whether unfired clay bricks from various sites can be dated accurately.
OSL techniques are being applied to date sediment sequences in stratigraphic contexts associated with irrigation systems. In the absence of suitable organic samples for C-14 dating, these systems are very difficult to date. New approaches are being applied to the dating of post-Roman irrigation systems in Spain to establish when they were created and used. Also, as part of a major investigation supported by the European Research Centre and led by Prof. E. Sauer at the University of Edinburgh, a PhD project has started to investigate the application of OSL and geomorphological techniques to establish the chronology of irrigation systems and settlement sites associated with the demographic growth at the frontiers of the Sasanian Empire.
Numerous water-control features such as relic canals, channels, and qanāts in the Gorgān Plain (Iran), Mil Steppe (Azerbaijan) and the Batinah Plain (Oman) were identified using remote sensing data and ground based survey. Excavation and sampling of these large-scale systems for luminescence dating has shown that canals were maintained over many centuries during their use prior to abandonment in the 10th Century AD (approximate time of the Hunnic Invasion). Further work is currently being undertaken to explore other nearby irrigation systems in Iraq and Syria such as qanāts and their potential for dating using luminescence.
Palaeolithic upland sites
Our novel extension of the single aliquot OSL measurement procedure enabled single grain measurements to be performed with ~90 μm diameter quartz and applied to relatively fine-grained brickearth. Horizons within a sequence containing Lower Palaeolithic artefacts on an upland site associated with a solution feature (doline) at West Cliffe in Kent were dated by OSL to between ca 140 and 80 ka ago, placing the deposition of the artefacts significantly later than indicated by the artefact typology (>300 ka). Contrary to the expectation of in situ burial indicated by earlier research, the cultural deposits were probably displaced from their primary context by processes associated with the development of the solution feature and this has important implications for establishing the timing of hominin use of the upland areas. Beyond broad attribution to Lower or Middle Palaeolithic origin the occurrence of displacement raises doubts regarding the interpretation of the environments that prevailed.