The Twannberg iron meteorite strewn field in the Swiss Jura mountains: insights for Quaternary environmental conditions

Swiss Journal of Geosciences

Table 4 Details of dose-rate calculations for IRSL dating

Sample	Coordinates (WGS84, °N/°E, and elevation, m a.s.l.)	Radionuclide concentration¹			Depth below surface (m)	Total dose rate² (Gy ka⁻¹)
Sample	Coordinates (WGS84, °N/°E, and elevation, m a.s.l.)	U (ppm)	Th (ppm)	K (%)	Depth below surface (m)	Total dose rate² (Gy ka⁻¹)
MS-01	47.14015/7.1628333/1280	4.76 ± 0.24	13.93 ± 0.70	1.06 ± 0.05	0.30 ± 0.05	4.21 ± 0.23
MS-02	47.14015/7.1628333/1280	4.76 ± 0.24	13.93 ± 0.70	1.06 ± 0.05	0.40 ± 0.05	4.21 ± 0.23
MS-03	47.14135/7.1568/1330	4.66 ± 0.23	12.34 ± 0.62	1.46 ± 0.07	0.40 ± 0.05	4.35 ± 0.23
MS-04	47.14135/7.1568/1330	4.66 ± 0.23	12.34 ± 0.62	1.46 ± 0.07	0.40 ± 0.05	4.35 ± 0.23
MS-05	47.14135/7.1568/1330	4.66 ± 0.23	12.34 ± 0.62	1.46 ± 0.07	0.20 ± 0.05	4.34 ± 0.23

¹Radionuclide concentrations were quantified on bulk samples using high-resolution gamma spectrometry (Department of Chemistry and Biochemistry, Univ. Bern)
²Dose rate calculations were performed with DRAC (Durcan et al., 2015), assuming water content of 25 ± 2% and bulk sample density of 2.3 g cm⁻³, an internal K-content of 12.5 ± 0.5% (Huntley & Baril, 1997) and an alpha efficiency value of 0.15 ± 0.05 (Balescu & Lamothe, 1994). Sampling location for MS-01/02 corresponds to find location of meteorite TW763. Sampling location for MS-03/04/05 corresponds to find location of meteorite TW141