Content

This dataset contains measurement sequences and data output of spatially resolved infrared radiofluorescence (SR IR-RF) measurements on K-feldspar samples carried out at the IRAMAT-CRP2A, UMR 5060, CNRS-Université Bordeaux Montaigne (France) in 2019. The data analysis was performed in 2020.

The data may serve as reference data and allow detailed inspection by others to verify or advance the used analysis procedures.

Along with the raw image data (TIF-files), the datasets also contain documented R (R Core Team, 2020) scripts used for data processing and partly treated data as an example. To reproduce the full data analysis, additional software is needed; not part of this repository.

Material and methods

Equipment

All measurements used single Freiberg Instruments lexsyg research luminescence reader (Richter et al., 2013) equipped with a Sr-90/Y-90 beta-source of irradiation and a Princeton Instruments ProEM512 for signal detection. Light output was filtered through a Chroma D850/40x interference filter. This means that the signal in the image data is infrared light.

The measurement sequence followed Frouin et al. (2017):

# STEP TREATMENT OBSERVATION
1 Shallow trap depletion Preheat at 70˚C for 900 s -
2 Natural dose IR-RF beta-irradiation at 70˚C for RF_nat
3 Signal resetting Bleaching with in-built solar simulator for 3 h -
4 Wait for phosphorescence to decay Pause for 1 h -
5 Shallow trap depletion Preheat at 70˚C for 900 s -
6 Regenerative dose IR-RF beta-irradiation at 70˚C for RF_reg

Samples

  1. TH0
  • Mineral: K-feldspar extract
  • Grain size: 125 − 250 μm
  • Origin: Sebkha Tah in Morocco
  • Reference: Bouab (2005)
  1. BDX16651
  • Mineral: K-feldspar extract
  • Grain size: 100 − 200 μm
  • Origin: Médoc area (France)
  • Reference: Kreutzer et al. (2018)

Software tools used

  • LexStudio2 (Freiberg Instruments GmbH): Measurement sequence writing, equipment control
  • ImageJ (Schneider et al., 2012): Image processing, extraction of regions of interests (ROI)
  • R (R Core Team, 2020): Post-image processing, data analysis and plotting
  • ‘Luminescence’ (Kreutzer et al., 2020): IR-RF data analysis
  • ‘RLumSTARR’ (Kreutzer and Mittelstrass, 20202): SR IR-RF data analysis
  • RStudio (https://rstudio.com): interactive programming environment for R

Data structure

| README.md
| README.html 
| - Results/
| -- BDX16651_SRIR-RF/
| -- TH0_P27_SRIR-RF/TH0_P27_SRIR-RF
| -- TH0_P28_SRIR-RF/
| -- TH0_PMT/
|- Sequences/ 
| -- BDX16651/
| -- TH0/

Folder Sequences/

This folder contains two subfolders, one for each measured sample, with the measurement sequences (ASCII-file format, file ending: *.lseq) used on the luminescence reader to produce the dataset. The sequence files were written with the proprietary software called LexStudio2 shipped with the measurement equipment.

Folder Results/

The folder contains the measurement output. Except TH0_PMT, Each folder contains, amongst other files and folders, two TIF-files (*.tif) with ending _RF_NAT_ and _RF_REG_. These files represent the raw, unprocessed, measurement output. All other files and folders are data analysis output including the R scripts used to produce the output.

Note: The TIF-file are not single images but image stack data. Means, the file contain a series of images.

If further subfolders contain files with the ending .Rproj, these files can reproduce the RStudio working environment. Pre-processed data can be found in further subfolders commencing with ROI_; trailing numbers indicate the ROI size. Each subfolder contains a file table.rf with more metadata.

Subfolder BDX16651_SRIR-RF/

Spatially resolved measurement output for sample BDX16651.

Subfolder TH0_P27_SRIR-RF/

Spatially resolved measurement output for sample TH0 from sample position 27 (position number refers to a position in the used measurement equipment).

Subfolder TH0_P28_SRIR-RF/

Spatially resolved measurement output for sample TH0 from the sample position 28 (position number refers to a position in measurement equipment). This dataset is a failed dataset, means the results are not meaningful due to equipment malfunction.

Subfolder TH0_PMT

Non-spatially resolved IR-RF measurement results for sample TH0. Measurements were performed with a photomultiplier tube (PMT) instead of the CCD camera. The raw data are stored in the XSYG-files (file ending *.xsyg, XML-format). The measurement was performed to calibrate the Sr-90/Y-90 of the reader.

Funding

The creation and the analysis of this dataset was supported by the LaScArBx LabEx, a programme supported by the ANR - n˚ ANR-10-LABX-52. The work of Sebastian Kreutzer in 2020 has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 844457 (CREDit).

References

Bouab, N.: Application Des Methodes de Datation Par Luminescence Optique À L’évolution Des Environnements Désertiques - Sahara Occidental (Maroc) Et Iles Canaries Orientales (Espagne), Ph.D. thesis, Université du Québec à Montréal, http://constellation.uqac.ca/ 868/1/13721974.pdf, 2005.

Frouin, M., Huot, S., Kreutzer, S., Lahaye, C., Lamothe, M., Philippe, A., and Mercier, N.: An improved radiofluorescence single-aliquot regenerative dose protocol for K-feldspars, Quaternary Geochronology, 38, 13–24, https://doi.org/10.1016/j.quageo.2016.11.004, http: //linkinghub.elsevier.com/retrieve/pii/S1871101416301704, 2017.

Kreutzer, S., Duval, M., Bartz, M., Bertran, P., Bosq, M., Eynaud, F., Verdin, F., and Mercier, N.: Deciphering long-term coastal dynamics using IR-RF and ESR dating: A case study from Médoc, south-West France, Quaternary Geochronology, 48, 108–120, https://doi.org/10.1016/j.quageo.2018.09.005, 2018.

Kreutzer, S., Burow, C., Dietze, M., Fuchs, M. C., Schmidt, C., Fischer, M., Friedrich, J., Riedesel, S., Autzen, M., and Mittelstrass, D.: Luminescence: Comprehensive Luminescence Dating Data Analysis, https://CRAN.R-project.org/package=Luminescence, R package version 0.9.9, 2020.

Kreutzer, S. and Mittelstrass, D.: RLumSTARR: Spatially Resolved Radiofluorescence Analysis, https://github.com/R-Lum/RLumSTARR, R package version 0.1.0.9000-49, 2020.

R Core Team: R: A Language and Environment for Statistical Computing, Vienna, Austria, https://r-project.org, 2020.

Richter, D., Richter, A., and Dornich, K.: lexsyg — a new system for luminescence research, Geochronometria, 40, 220–228, https://doi.org/10.2478/s13386-013-0110-0, 2013.

Schneider, C. A., Rasband, W. S., and Eliceiri, K. W.: NIH Image to ImageJ: 25 years of image analysis, Nature Methods, 9, 671–675, https://doi.org/10.1038/nmeth.2089, http://www.nature.com/doifinder/10.1038/nmeth.2089, 2012.