Table 4 Grain size properties pre- and post-HF etching based on static image analysis and external alpha dose rate calculation using DRAC v1.250.

From: First experimental evaluation of the alpha efficiency in coarse-grained quartz for ESR dating purposes: implications for dose rate evaluation

Sample ID

Mean CE diameter pre-HF etching (µm)

Mean CE diameter post-HF etching (µm)

Etching depth (µm) (a)

Scenario #1

Scenario #2

Scenario #3

External alpha dose rate (µGy/a)

% of total dose rate(b)

ESR age (ka)

ESR age ratio(c)

External alpha dose rate (µGy/a)

% of total dose rate(c)

ESR age (ka)

ESR age ratio(c)

External alpha dose rate (µGy/a)

% of total dose rate(b)

ESR age (ka)

ESR age ratio(c)

C-E3824

198.3 ± 1.7

181.1 ± 2.2

8.6 ± 0.1

10 ± 8

1.2

1281 ± 97

1.02

4 ± 3

0.5

1291 ± 97

1.03

9 ± 1

1.1

1277 ± 96

1.01

C-E3886

185.4 ± 9.1

156.5 ± 4.9

14.5 ± 0.8

18 ± 14

1.5

1330 ± 13

1.01

6 ± 5

0.5

1343 ± 135

1.02

7 ± 1

0.6

1341 ± 134

1.02

C-E3888

146.2 ± 1.1

143.5 ± 4.5

1.4 ± 0.04

21 ± 18

1.8

1270 ± 96

1.00

7 ± 6

0.6

128 ± 95

1.01

39 ± 5

3.3

1237 ± 91

0.98

C-E3891

185.4 ± 14.5

166.7 ± 4.0

9.4 ± 0.8

13 ± 10

1.4

1246 ± 98

1.01

4 ± 3

0.4

1257 ± 98

1.02

10 ± 2

1.1

1245 ± 97

1.01

  1. Note that post-HF etching sieving has been performed using a 90 µm opening size sieve. (a)calculated as the half of the difference in CE diameter, (b)based on an internal dose rate of 50 ± 30 µGy/a, (c)Compared to the original ESR ages published by Bartz et al.20.
  2. Scenario #1: assumed alpha efficiency = 0.2; original grain size = measured mean CE diameter; assumed etching depths of 20 ± 10 µm.
  3. Scenario #2: measured alpha efficiency = 0.07; original grain size = measured mean CE diameter; assumed etching depths of 20 ± 10 µm.
  4. Scenario #3: measured alpha efficiency = 0.07; original grain size = measured mean CE diameter; measured etching depths.
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