Table 8.
Properties and analytical data for boulders on the Sampesa (SA), Syntabul –Severokokorsky (NK) and Upper Taimyra – Baikuronyora (UT_B) Ice Marginal Zones (IMZ) analysed for cosmogenic36Cl (TCN exposure dating). Altitudes, latitudes, and longitudes were determined with GPS. For all samples, measured bulk rock density is 3.0 g/cm3, thickness is 5.0 cm, and topographic shielding is negligible. The rock dissolved indicates the amount processed for AgCl extraction chemistry. The Cl carrier is from PRIME Lab and has a35Cl/37Cl ratio of 273. Uncertainties on35Cl/37Cl and36Cl/Cl ratios and exposure ages represent propagated 1σ analytical/internal uncertainties only. Sample36Cl concentrations are corrected for36Cl contributed by procedural blanks. Exposure age uncertainties in parentheses incorporate external uncertainties, including production rate uncertainties; comparisons of the36Cl ages with those derived from independent chronometers (e.g., radiocarbon, OSL) must account for these external uncertainties. Ages “w/erosion” are calculated with a prescribed rock surface erosion rate of 1 mm/kyr. See Fig. 21 in [1] for site locations on map (*).
| Sample | PRIME ID | Lat. (°N) | Lon. (°E) | Elev. (m) | Site # map* | Boulder size (m) | Rock diss. (g) | Cl carrier (mg) | 35Cl/37Cl (±1σ) | 36Cl/Cl (e−15, ±1σ) | 36Cl conc. (e4 at/g, ±1σ) | Exposure Age (ka, ±1σ) | Age w/erosion (ka, ±1σ) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Upper Taimyra – Baikuronyora IMZ | |||||||||||||
| UT_B-1 | 201103318 | 73.96507 | 102.69740 | 134 | 1 | 0.7 × 0.7 | 31.1458 | 1.0550 | 5.951 ± 0.001 | 135.18 ± 9.45 | 17.73 ± 1.24 | 22.1 ± 1.7 (2.4) | 22.0 ± 1.6 (2.3) |
| UT_B-2 | 201103319 | 73.79550 | 101.17040 | 123 | 2 | 2.6 × 2.0 | 30.3340 | 1.0406 | 3.437 ± 0.005 | 57.66 ± 8.18 | 39.96 ± 5.67 | 15.6 ± 2.4 (3.5) | 15.1 ± 2.2 (3.4) |
| UT_B-3 | – | 73.99403 | 99.54113 | 163 | 3 | 2.3 × 1.6 | – | – | – | – | – | – | – |
| UT_B-4 | 201900689 | 73.99402 | 99.54150 | 236 | 4 | 2.4 × 1.5 | 20.2981 | 1.0303 | 3.295 ± 0.021 | 79.30 ± 2.99 | 174.01 ± 21.97 | 26.9 ± 4.1 (6.8) | 25.2 ± 3.6 (6.1) |
| Syntabul – Severokokorsky IMZ | |||||||||||||
| NK-1 | 201900690 | 73.98318 | 104.87208 | 130 | 5 | 2.0 × 2.0 | 20.1047 | 1.0281 | 6.285 ± 0.026 | 364.05 ± 8.95 | 72.32 ± 1.82 | 84.1 ± 2.5 (7.8) | 83.0 ± 2.9 (8.7) |
| NK-2 | 201103320 | 73.96920 | 103.47693 | 137 | 6 | 1.5 × 1.3 | 31.4587 | 1.1095 | 3.666 ± 0.009 | 291.41 ± 10.69 | 146.35 ± 5.37 | 81.0 ± 3.8 (13) | 72.0 ± 3.9 (12) |
| NK-3 | – | 73.96918 | 103.47695 | 143 | 7 | 1.2 × 1.2 | – | – | – | – | – | – | – |
| NK-4 | – | 73.04255 | 101.33038 | 155 | 8 | 0.8 × 0.6 | – | – | – | – | – | – | – |
| NK-5 | 201900691 | 73.04275 | 101.33102 | 156 | 9 | 0.7 × 0.6 | 20.1122 | 1.0276 | 4.740 ± 0.019 | 327.81 ± 6.82 | 100.57 ± 2.27 | 79.5 ± 2.8 (9.9) | 74.8 ± 2.8 (9.9) |
| NK-6 | – | 73.73607 | 98.38002 | 189 | 10 | 1.7 × 1.5 | – | – | – | – | – | – | – |
| NK-7 | 201900692 | 72.20930 | 101.63160 | 175 | 11 | 2.7 × 2.5 | 20.0517 | 1.0284 | 6.237 ± 0.034 | 499.23 ± 10.96 | 100.54 ± 2.31 | 109 ± 3.1 (9.5) | 110 ± 3.6 (11) |
| NK-8 | 201103321 | 73.44448 | 102.80750 | 137 | 12 | 0.7 × 0.6 | 30.4033 | 1.0197 | 3.504 ± 0.200 | 281.91 ± 11.88 | 185.85 ± 7.83 | 92.0 ± 4.6 (17) | 82.0 ± 4.3 (15) |
| Sampesa IMZ | |||||||||||||
| SA-1 | 201103322 | 72.01557 | 97.55150 | 131 | 13 | 1.0 × 0.9 | 30.7504 | 1.0578 | 7.276 ± 0.035 | 776.30 ± 28.52 | 89.30 ± 3.28 | 131 ± 5.8 (11) | 139 ± 7.1 (14) |
| SA-2 | 201900693 | 72.01587 | 97.55788 | 121 | 14 | 0.8 × 0.8 | 20.1556 | 1.0283 | 3.351 ± 0.015 | 322.60 ± 7.77 | 541.72 ± 36.83 | 120 ± 11 (29) | 98.0 ± 8.4 (22) |
| SA-3 | 201900694 | 72.20662 | 98.45890 | 65 | 15 | 0.7 × 0.7 | 20.2505 | 1.0264 | 10.145 ± 0.104 | 310.07 ± 8.30 | 41.81 ± 1.16 | 54.5 ± 1.7 (3.8) | 55.4 ± 1.8 (4.2) |
| SA-4 | 201103323 | 72.20757 | 98.45793 | 78 | 16 | 0.7 × 0.7 | 3.6687 | 1.0757 | 7.308 ± 0.001 | 359.88 ± 13.12 | 346.22 ± 12.62 | 249 ± 15 (51) | 215 ± 15 (49) |
| Procedural blank | |||||||||||||
| CLBLK-20 | 201900696 | – | – | – | – | – | – | 1.0285 | 167.1 ± 22.2 | 5.86 ± 0.90 | – | – | – |
Samples are sorted beneath their respective Ice Marginal Zones (IMZ), named in bold.