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Table 2 Summary of zircon (U–Th)/He parameters

From: First report of (U–Th)/He thermochronometric data across Northeast Japan Arc: implications for the long-term inelastic deformation

Sample Lab. no He no. No. of grains analyzed [4He]
(ncc)
Mass
(mg)
aMean F T [U]
(ppm)
[Th]
(ppm)
Th/U b[eU]
(ppm)
Corrected age ± 1σ
(Ma)
Grain length
(μm)
Grain radius
(μm)
cGrain morphology
A02-ST04 11241 34006 1 21.124 0.0146 0.83 308.4 122.0 0.40 337.1 35.1 ± 2.2 305.5 60.1 2T
A02-ST04 11242 34009 1 36.171 0.0218 0.84 297.6 103.1 0.35 321.8 42.3 ± 2.6 411.9 60.1 2T
A02-ST04 11243 34012 1 38.534 0.0298 0.87 250.4 108.9 0.43 276.0 38.3 ± 2.4 349.9 84.0 2T
A02-ST04 11244 34037 1 22.589 0.0116 0.82 316.3 133.6 0.42 347.7 46.0 ± 2.9 270.1 57.8 2T
          Weighted mean age ± 95% CI 39.6 ± 7.4    
A02-ST05 11237 33994 1 8.232 0.0186 0.83 130.4 43.9 0.34 140.7 25.8 ± 1.6 371.3 59.2 2T
A02-ST05 11238 33997 1 10.409 0.0220 0.85 357.4 111.8 0.31 383.6 10.1 ± 0.6 363.2 66.7 2T
A02-ST05 11239 34000 1 2.846 0.0089 0.80 273.6 117.8 0.43 301.3 8.7 ± 0.5 254.2 51.9 2T
A02-ST05 11240 34003 1 5.915 0.0093 0.79 306.1 80.7 0.26 325.1 16.1 ± 1.0 294.5 47.0 2T
          Weighted mean age ± 95% CI N/A    
A02-ST06 11233 33982 1 35.540 0.0146 0.83 839.8 278.8 0.33 905.3 22.1 ± 1.4 295.4 61.8 2T
A02-ST06 11234 33985 1 55.748 0.0269 0.86 386.1 144.4 0.37 420.0 40.4 ± 2.5 388.6 71.3 2T
A02-ST06 11235 33988 1 19.360 0.0154 0.83 303.2 115.9 0.38 330.5 31.2 ± 1.9 299.0 63.3 2T
A02-ST06 11236 33991 1 20.796 0.0106 0.81 504.5 160.2 0.32 542.2 29.8 ± 1.8 273.3 54.0 2T
          Weighted mean age ± 95% CI N/A    
A02-ST07 11230 33918 1 5.562 0.0080 0.79 209.3 102.9 0.49 233.5 24.5 ± 1.5 238.6 51.1 2T
A02-ST07 11231 33976 1 11.496 0.0086 0.78 348.2 140.3 0.40 381.1 28.9 ± 1.8 320.1 42.2 2T
A02-ST07 11232 33979 1 12.184 0.0068 0.79 471.6 192.5 0.41 516.8 28.3 ± 1.8 216.1 50.9 2T
A02-ST07 11313 34052 1 26.722 0.0122 0.82 596.6 179.3 0.30 638.7 28.1 ± 1.7 278.0 58.3 2T
          Weighted mean age ± 95% CI 27.2 ± 3.3    
A02-ST08 11225 33903 1 48.968 0.0105 0.81 550.4 233.9 0.42 605.3 62.8 ± 3.9 260.9 56.3 2T
A02-ST08 11226 33906 1 37.863 0.0184 0.85 241.6 89.8 0.37 262.7 64.2 ± 4.0 289.0 73.7 2T
A02-ST08 11227 33909 1 29.750 0.0128 0.83 394.8 162.7 0.41 433.0 43.8 ± 2.7 265.5 63.0 2T
A02-ST08 11228 33912 1 34.455 0.0164 0.82 305.3 123.6 0.40 334.3 51.6 ± 3.2 373.3 54.7 2T
          Weighted mean age ± 95% CI N/A    
A02-ST09 11221 33891 1 9.199 0.0099 0.80 686.1 307.7 0.45 758.5 10.0 ± 0.6 290.2 49.5 2T
A02-ST09 11222 33894 1 11.643 0.0125 0.82 529.5 132.4 0.25 560.6 13.7 ± 0.8 315.7 53.1 2T
A02-ST09 11224 33900 1 12.592 0.0095 0.79 889.9 310.4 0.35 962.8 11.3 ± 0.7 310.5 45.8 2T
A02-ST09 11314 34055 1 4.012 0.0116 0.82 252.1 110.7 0.44 278.1 10.2 ± 0.6 268.9 58.3 2T
          Weighted mean age ± 95% CI 11.0 ± 2.4    
A02-ST13 11217 33879 1 33.892 0.0081 0.80 501.6 170.2 0.34 541.6 63.3 ± 3.9 245.9 50.2 2T
A02-ST13 11218 33882 1 25.187 0.0078 0.80 2016.2 518.8 0.26 2138.1 12.4 ± 0.8 239.2 50.2 2T
A02-ST13 11219 33885 1 24.142 0.0174 0.84 1203.4 255.7 0.21 1263.4 9.0 ± 0.6 306.1 67.1 2T
A02-ST13 11220 33888 1 27.567 0.0105 0.81 901.6 203.8 0.23 949.5 22.6 ± 1.4 267.2 55.0 2T
          Weighted mean age ± 95% CI N/A    
A02-ST15 11213 33870 1 31.938 0.0095 0.81 697.5 281.3 0.40 763.6 36.2 ± 2.2 252.3 54.2 2T
A02-ST15 11214 33873 1 58.324 0.0058 0.77 2506.9 893.1 0.36 2716.8 30.2 ± 1.9 222.5 44.6 2T
A02-ST15 11215 33876 1 53.732 0.0109 0.81 1253.7 471.0 0.38 1364.4 29.7 ± 1.8 298.2 51.2 2T
A02-ST15 11216 33940 1 74.872 0.0070 0.79 2883.1 791.4 0.27 3069.1 28.8 ± 1.8 239.2 46.8 2T
          Weighted mean age ± 95% CI 30.7 ± 4.8    
Fish Canyon Tuff standard
FCT 11088 33750 1 7.695 0.0062 0.77 317.8 155.8 0.49 354.4 28.6 ± 1.8 236.2 44.1 2T
FCT 11089 33753 1 9.671 0.0056 0.77 462.1 288.8 0.62 530.0 26.8 ± 1.7 214.6 44.8 2T
FCT 11090 33846 1 12.907 0.0112 0.81 286.7 145.9 0.51 321.0 29.5 ± 1.8 299.2 51.8 2T
FCT 11093 33855 1 10.809 0.0068 0.77 369.0 253.7 0.69 428.6 30.4 ± 1.9 271.2 41.7 2T
FCT 11094 33858 1 9.219 0.0091 0.80 271.6 152.1 0.56 307.3 27.1 ± 1.7 254.5 52.3 2T
          Weighted mean age ± 95% CI 28.4 ± 1.5    
          dReference age ± 1σ: 28.01 ± 0.04    
  1. The weighted mean ages and the errors were obtained using Isoplot ver. 4.15 (Ludwig 2012). For samples exhibiting a negative correlation between eU and grain ages, weighted mean ages were not calculated and are reported as “N/A”
  2. a F T is α-ejection correction after Farley et al. (1996)
  3. bEffective uranium concentration, weights U and Th for their alpha productivity, computed as [U] + 0.235[Th] (Shuster et al. 2006)
  4. cCrystal morphology: 2T = idiomorphic whole grain (Brown et al. 2013)
  5. dThe reference age of Fish Canyon Tuff (FCT) is from Phillips and Matchan (2013)