Timing of retreat of the Reuss Glacier (Switzerland) at the end of the Last Glacial Maximum

Swiss Journal of Geosciences

Table 3 Cosmogenic ³⁶Cl data and exposure ages of carbonate and conglomerate samples

³⁶Cl sample name	Weight of sample (g)	Cl conc. in rock (ppm)	³⁶Cl conc. (×10⁴ ³⁶ Cl g (Ca)⁻¹)	Erosion corrected (ε = 3.0 mm/ka) Exposure age (ka)
Rigi-5	54.5830	12.04 ± 0.07	75.5 ± 3.5	15.4 ± 0.9^a
Rigi-6	43.6201	46.51 ± 0.85	49.5 ± 2.3	11.6 ± 0.7
Rigi-7	56.2160	42.09 ± 0.35	86.9 ± 3.0	20.4 ± 1.0
Rigi-8	53.5607	33.48 ± 0.23	55.7 ± 2.2	15.5 ± 0.8
Rigi-9	58.4413	13.28 ± 0.05	69.4 ± 2.6	16.3 ± 0.8

Analytical errors are at 1σ level, including the statistical (counting) error and the combined counting uncertainty and the uncertainty due to normalization of standards and blanks. To calculate exposure ages we have used 48.8 ± 1.7 atoms ³⁶Cl g (Ca)⁻¹ a⁻¹ SLHL production rate from Ca spallation, 5.3 ± 0.5 ³⁶Cl g (Ca)⁻¹ a⁻¹ SLHL production due to muon capture (Stone et al. 1996, 1998, one sigma errors) and scaled after Stone (2000) to 2.47 (spallation) and 1.61 (muonic) of the SLHL values. Low-energy capture of thermal and epithermal neutrons is computed following Liu et al. (1994) and Phillips et al. (2001) using the production rate of epithermal neutrons above the surface 760 ± 150 neutrons g⁻¹ a⁻¹ (see Alfimov and Ivy Ochs 2009). Exposure ages are corrected for shielding of surrounding topography and sample thickness
^aRigi-5 is a limestone therefore, a higher erosion rate of 5.0 mm/ka is used for calculation