Carr, A. S., Hay, A. S., Powell, M. and Livingstone, I. (2018) Testing post-IR IRSL luminescence dating methods in the southwest Mojave Desert, California, USA. Quaternary Geochronology. 49, pp. 85-91. 1871-1014.
| Item Type: | Article |
|---|---|
| Abstract: | The Mojave Desert presents an array of Pleistocene lacustrine deposits and aeolian landforms to which, at times, it has proved challenging to apply luminescence methods. We tested the suitability of K-feldspar post-IR IRSL methods using two sites with independent radiocarbon dating – shorelines at Harper Lake and Silver Lake – considering: 1) overall performance of the post-IR IRSL 225 °C (pIRIR225) protocol; 2) effect of test dose size on pIRIR225 De; 3) anomalous fading correction of pIRIR225 ages; 4) preliminary single grain pIRIR225 results. We observe consistently good performance of the single aliquot pIRIR225 protocol, with good dose recovery, acceptable recycling ratios, low recuperation and low inter-aliquot scatter. The pIRIR225 ages for Silver Lake (8.8 ± 0.4 and 11.3 ± 0.5 ka) and Harper Lake (both 25.4 ± 1.4 ka) are in substantially better agreement with the independent dating than low temperature (50 °C) IRSL and quartz OSL ages. pIRIR225 fading rates are reduced to ∼2.0–2.5% per decade, but there remains a tendency for under-estimation when using uncorrected ages. A need for fading correction is further implied at Harper Lake via comparison with multi-elevated temperature (MET)-PIR age plateaus and pIRIR290 measurements, although at the younger Silver lake site these methods produce ages nearly identical to the uncorrected pIRIR225 ages. Preliminary single grain pIRIR225 measurements suggest a ∼25–30% usable grain yield. At Silver Lake the single grain and single aliquot ages agree well despite over-dispersion of the single grain equivalent dose distribution. At Harper Lake the single grain and single aliquot pIRIR225 ages also agree well, although a population of insensitive, lower De grains is observed. These grains are not associated with significantly higher fading rates. |
| Creators: | Carr, Andrew S., Hay, Alex S., Powell, Mark and Livingstone, Ian |
| Faculties, Divisions and Institutes: | Faculties > Faculty of Arts, Science & Technology > Environmental Science |
| Date: | 8 May 2018 |
| Date Type: | Acceptance |
| Page Range: | pp. 85-91 |
| Journal or Publication Title: | Quaternary Geochronology |
| Volume: | 49 |
| Number of Pages: | 7 |
| Language: | English |
| DOI: | https://doi.org/10.1016/j.quageo.2018.05.006 |
| ISSN: | 1871-1014 |
| Status: | Published / Disseminated |
| Refereed: | Yes |
| Related URLs: | |
| URI: | http://nectar.northampton.ac.uk/id/eprint/11760 |
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