Fig. 1
Map showing the location of Jinchang paleolake (star) and other sites (Baijian Lake, Tegger Desert, Mu us Desert, Otindag Desert and Horqin Desert) mentioned in this study. EAM denotes East Asian monsoon, and its northern limit is shown by the blue dashed line (inset).
Fig. 2
Photos of outcrop sampled for luminescence and radiocarbon dating.
Fig. 3
Preheat temperature plateau tests for quartz samples: NL-579 (a), NL-580 (b), and NL-581 (c).
Fig. 4
Histogram summarizing dose recovery ratios for three quartz samples.
Fig. 5
(a) The normalized OSL decay curve of sample NL-579 was decomposed into three components, i.e., fast, medium and slow plus BG; (b) the relative contribution of the three components are plotted against stimulation time; decay curves and growth curves of K-feldspar pIRIR150 (c) and pIRIR225 (d) signals for sample NL-579.
Fig. 6
De distribution of quartz OSL for three samples.
Table 1
Luminescence dating results for three samples.
| Sample ID | Depth (m) | U (ppm) | Th (ppm) | K (%) | Luminescence signals | Total dose rate (Gy/ka) | De (Gy) | Age (ka) |
|---|---|---|---|---|---|---|---|---|
| NL-579 | 3.2 | 2.88 ± 0.11 | 4.30 ± 0.16 | 2.13 ± 0.06 | Qz OSL | 2.82 ± 0.20 | 22.1 ± 1.0 | 7.8 ± 0.7 |
| K-feldspar pIRIR150 | 3.63 ± 0.22 | 28.7 ± 0.7 | 7.9 ± 0.5 | |||||
| K-feldspar pIRIR225 | 3.63 ± 0.22 | 26.9 ± 0.4 | 7.4 ± 0.5 | |||||
| NL-580 | 1.7 | 2.13 ± 0.09 | 4.21 ± 0.16 | 1.87 ± 0.06 | Qz OSL | 2.48 ± 0.17 | 18.4 ± 0.6 | 7.4 ± 0.6 |
| K-feldspar pIRIR150 | 3.26 ± 0.21 | 24.4 ± 0.1 | 7.5 ± 0.5 | |||||
| K-feldspar pIRIR225 | 3.26 ± 0.21 | 24.4 ± 0.6 | 7.5 ± 0.5 | |||||
| NL-581 | 1.0 | 3.52 ± 0.12 | 8.02 ± 0.25 | 1.76 ± 0.06 | Qz OSL | 2.91 ± 0.19 | 22.2 ± 0.7 | 7.6 ± 0.6 |
| K-feldspar pIRIR150 | 3.76 ± 0.23 | 28.7 ± 0.3 | 7.6 ± 0.5 | |||||
| K-feldspar pIRIR225 | 3.76 ± 0.23 | 27.9 ± 0.3 | 7.4 ± 0.5 |
Fig. 7
(a) Dose recovery tests and (b) residual test on K-feldspar pIRIR150 (black) and pIRIR225 (red) signals; (c) fading rates of K-feldspar pIRIR150 (black) and pIRIR225 (red) signals; (d) fading rates of IRSL50 signals measured by pIRIR150 (black) and pIRIR225 protocols.
Fig. 8
All luminescence and 14C ages demonstrated together with the lithological log of JC section.