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Fig. 1
Sketch map showing study area, sampling sites as well as geomorphological and geological setting of sampling sites. a) Study area located on eastern Tibet Plateau and its geomorphological map; b) geological setting and sampling site of Mian’ning River and Diao’tengzi River. Due to that the Mian’ning River is too small to be marked on the map, we represent both of the two sampling sites as one spot in Fig. 1b). The bedrock age data came from China Intrusive Rock Isotope Age Figure by K-Ar dating method.
Fig. 2
Typical E1’ centre ESR spectrum of quartz in MN05 sample.
Fig. 3
Bleaching curve of the E1’ centre of quartz extracted from three storing origins.
Fig. 4
The E1’ signal intensity change level (%) with different light exposure time. The increase level of the E1’ centre is the ratio between increase value of its natural intensity. All sample nature E1’ centre ESR signal intensity are of numerical normalized as 1 (100%). After 400 h, the E1’ centre of three samples show a relatively steady increasing level with a range of 235 ~ 270%, about 2.5 times of its nature.
Fig. 5
The E1’ centre signal intensity changes with dose irregularly.
Each measured point and its bleaching duration.
Measured point No.
1
2
3
4
5
6
7
8
9
Bleaching duration (h)
0
0.5
1.5
2
4
8
16
32
84
Measured point No.
10
11
12
13
14
15
16
17
18
Bleaching duration (h)
102
134
151
184
202
231
260
300
350
Measured point No.
19
20
21
22
Bleaching duration (h)
400
500
700
900
List of sample information used in this study. All samples were collected from the southeast margin of the Tibet Plateau, which is located in the junction between the first and second ladder of China terrain. The quartz extracted from bedrock (MN05) was sampled 10 mm beneath its surface; DTZG03 was sampled at 0.7 m beneath the surface deposits; MN06 was collected from the modern floodplain. MN05 and MN06 were collected from the same river drainage with unitary lithology of granite.