luminescence.de: A science blog
by Dirk Mittelstraß | Last update: Feb 16, 2025
Luminescence dating might be the best tool to determine the age of landscapes and archaeological artefacts in the last 400,000 years. This blog is about publications which I find interesting or where I contributed too. And it is about my own two projects: The R package OSLdecomposition for enhancing the accuracy of optically stimulated luminescence (OSL) dating, and the further development of the radiofluorescence dating method for obtaining sediment chronologies and provenance marker.
Map of some publications using luminescence dating
Zoom in and click on the circles to get the reference and a list of used methods. The circles show the sampling location: Small circle means the location is stated exactly, whereas for larger circles the sample side is either not exactly indicated or a larger area. Purple circles refer to recent publications, gray circles to older publications.
Recently I got myself into data mining and creating interactive maps. As input data, I used publications about the Quaternary that I had either used as reference in the past or that I find interesting. In the end, I got the map you see above. I will publish an extended and more detailed version of the map as well as the code and data behind it soon. If you are interested in the data or if you want to add publications to the map, please contact me.
Dislcaimer: The map is based on the Leaflet package for R and the OpenStreetMap project. All data is taken from publications that fall under copyright law. However, I assume to the best of my knowledge and belief that the interactive map published here falls under the Fair Use policy for non-commercial purposes. If a copyright holder believes that the map violates their rights, contact me and I will remove the data in in question.
News
2024-11-12 Back from the DLED 2024
The Central European luminescence and ESR dating conference this year was held in Jelenia Góra, Poland. It took place at a beautiful castle (see picture). Organisation and catering were great! Many thanks to the organisation team consisting of Fatima, Grzegorz, Konrad and Joanna from the Silesian University of Technology and miDose.
Of course, there were also some interesting talks and posters. For the luminescence dating community the following news are probably the most interesting:
The jounal Geochronometria has a new website and two new editors. And best of all, it is free-of-charge until further notice.
The journal AncientTL also has a new website and a new chief editor, Christoph Schmidt from the University of Lausanne. As ever, AncientTL is also free of charge. However, it is not indexed. On the other hand, publishing in AncientTL is quite fast and less restrictive. This means that it is particularly suitable for side projects that do not fit into any other luminescence dating journal.
Freiberg Instruments now offers a single-grain OSL laser stimulation module for their Lexsyg Research devices. I’m curious how the first experience reports from users will be.
And of course, I participated with a poster. This time, I had a look if IR-RF signal curve features can be used to distinct between samples of different origin using Principal Component Analysis. And yes, it works:
For more information, see my poster here.
2023-07-20 OSLdecomposition package is actually used!
Last month I visited the Luminescence and ESR dating conference in Copenhagen and was surprised and happy to find out that my R package OSLdecomposition is already used (or at least tested) by some work groups while others are interested to use it in the future. I was not aware of that because I got no feedback so far. However, that gave me renewed motivation to finish the scientific paper about the OSLdecomposition R package.
If you like to cite the package before the paper is available please use the reference you get if you type this in R:
By the way, I outlined the future update to 1.1.0:
- Add a
Method.controlargument andK.mintofit_OSLcurve()to allow more tweaking of the genetic algorithm. - Possibility to set one or more fixed decay constant to
fit_OSLcurve()to enable interesting new fitting approaches. - Revise
plot_OSLcurve(), especially add the option to draw the signal components as stacked areas. - Add HMTL report output to
RLum.OSL_correction(). - Simplify the component analysis for IR-RF measurements by adding the
new wrapper functions
RLum.RF_correction()andRLum.RF_fitting(). - Add a function
get_RLum.sequence()to return the measurement sequences used in a data set asknitr-compatible table and include it inRLum.OSL_correction(). andRLum.RF_correction(). - Revise
sum_OSLcurves(), especially speed up the far too slow plot output. - Ensure the package is ready for the XLUM data format.
Much of the above points were already coded and tested for other projects and just need to be merged into the main branch of OSLdecomposition. However, as this update has not the highest priority for me right now and the whole development is a hobbiest project anyway, please do not expect that the update will be released within the next months. Nonetheless, I will keep you updated and invite everyone to write their comments and wishes in the associated GitHub thread.
2023-06-25 IR-RF component fitting
In my latest side project, I analysed the shapes of IR-RF signal curves of a variety of K-feldspar samples with methods from OSLdecomposition. Apparently, IR-RF curves can be sufficiently described by multi-exponential fittings, see the example below. Although further investigations are necessary, I summarized my findings in my poster for the LED conference 2023.
2022-11-16 Sontag-Gonzales et al. (2022) published in Radiation Measurements
A new scientific paper I co-authored is published: Wavelength calibration and spectral sensitivity correction of luminescence measurements for dosimetry applications: Method comparison tested on the IR-RF of K-feldspar written by Mariana Sontag-Gonzales who is part of Markus Fuchs’s work group in Giessen. Mariana did an excellent job in describing multiple approaches for wavelength and sensitivity calibration of for luminescence spectroscopy and comparing them. As case study, the paper includes also IR-RF peak analyses of two K-feldspar samples. doi: 10.1016/j.radmeas.2022.106876.
2022-08-14 Package OSLdecomposition is released on CRAN
Finally, my OSLdecomposition function library for R is released on CRAN. The package can now be installed using the RStudio package manager or by simply typing this into your R environment:
If you are not familiar with what it is all about or how to use the package, check out the Introduction & Tutorial page.
2021-06-19 Spatially resolved IR-RF paper published / vDEUQUA 2021
The research article presenting the method of grain-wise IR-RF dating of K-feldspars developed by Sebastian Kreutzer and myself has passed the review process in Geochronology and is now officially available at doi.org/10.5194/gchron-3-299-2021.
If you would like to discuss the future of IR-RF dating with me or Sebastian, why not register for the vDEUQUA 2021 online conference? The vDEUQUA is about quaternary climate and environmental changes, the methods to investigate them and how quarternary processes shaped our todays world. The conference is virtual, free of charge and happens from 2021-09-30 to 2021-10-01. See you there!
2020-11-26 ‘OSLdecomposition’ pre-release
Just in time for the DLED2020,
we released our R package OSLdecomposition for
signal component identification and separation in multi-exponentially
decaying measurements. Our focus laid on continous-wave optically
stimulated luminescence (CW-OSL) measurements of quartz samples for
dosimetry purposes. But you might find the package helpful for other
applications too. Check out our DLED
poster for a quick introduction into the Why and
How.
© Dirk Mittelstraß, 2020 - 2025 | This website was created with Rmarkdown