top of page
-
How do I sample for Luminescence dating?These notes are based on contexts where the sediments are not consolidated and can be driven into the strata without buckling. For any other context please contact us for advice. Recording Prior to sampling, take a photograph of the cleaned section. Once sample locations have been selected (insertion of tubes) take a second photograph to show the location of the samples. Assign site code, context/sample number for each section sampled. Describe contexts (soil texture, sorting, particle size and colour) and produce a section drawing to show the contexts, record sample locations (depths below datum and showing position of ground surface) and contacts. Sampling Only samples not exposed to light can be used for dating measurements - i.e., beyond ca 5 cm behind an excavated face and contained in an opaque sample tube or within the interior of a sediment block cut to provide material surrounding the sample volume of at least several cm. Black plastic or steel tubes (e.g. 40 mm dia) at least 15 cm long can be used for sampling where the sediment is not highly consolidated. The tubes should be fully packed with material with any space at each end filled to avoid mixing during transport. Tubes are taken from sedimentary units that are homogenous avoiding boundaries/thin units unless block sampled; in the case of a major interface, sample above and below the contact. If there are multiple thin layers, and the sediment consolidated, excavation of blocks is appropriate. If tubes are inserted above and below the contact at each interface, this will provide a sequence of samples, two from each layer (basal and upper). In addition to extracting sediment from the tubes for luminescence measurements, the material is also analysed for radionuclide concentration (U/Th/K) and for any given dating sample, samples of sediment representative of the major strata up to ca 30 cm from the dating sample are required. If these strata have not been sampled for dating (i.e. using tubes), smaller samples for radioactive analysis only may be collected in clear polythene sealable bags (25g is sufficient). Samples should be wrapped in opaque plastic sheet (use ‘lay-flat’ plastic tubing if available) and sealed with duct tape marked with site code, section, sample number, and direction of tube insertion (inner vs outer) should be clearly indicated on the tube. Packing and transport Tubes should be packed in a shock absorbing material to reduce the risk of disaggregation when transported.
-
How much does it cost?The price of luminescence dating varies depending on the antiquity of the sample, the nature of the dated material, the level of precision for the dating (measurements of single-grains or aliquots) and the number of samples measured per site. Contact us for quotations.
-
How long does it take?Turnarounds times for the measurements vary depending on the number of samples to be measured, their nature and their antiquity. Commonly it takes ~8 weeks after reception of the samples but can be as little as 2 weeks. Contact us for further details and more precise estimates.
-
Where to send?Please send samples only if our quotation is accepted. The samples should be clearly labelled with their sample code, and accompanied with docs giving an estimate of the expected age (e.g. Holocene, Bronze age, Medieval, Younger Dryas, LGM, MIS5, etc.), the depositional context of the material (e.g. glacio-fluvial sediments, cave, rock shelter, fluvial terraces, lake deposits, aeolian sediments, etc.), the depth (in cm) of the samples, the coordinates (WGS84 in decimal degrees) / altitude (m) of the site(s) sampled, and any relevant observation made on-site. This additional information can also be provided by email prior to sending the samples. The package(s) should be marked with "Light sensitive material, Inert geological samples, no commercial value, to be tested to destruction. Please do not expose to light. Please check attached docs and contacts for details." If you are sending your samples from abroad, make sure to fill in a CN22 or CN23 Customs declaration form (https://www.royalmail.com/sites/default/files/CN23.pdf), and pay the full postal fees, to avoid Customs clearance fees and delays. The package(s) can then be sent to : Dr. Eric Andrieux Durham Luminescence dating Laboratory Department of Archaeology, University of Durham Lower Mount Joy, South Rd, Durham DH1 3LE United Kingdom Contact: eric.j.andrieux[at]durham.ac.uk
bottom of page