Table 1.

Table of apatite (U–Th)/He data from the Cumberland Peninsula

Sample (mean)*He (Vol (10−9 cm3))U (ppm)Th (ppm)Sm (ppm)eU† (ppm)Length (µm)Width (µm)r'‡ (µm)Ft§Measured age (Ma)Corrected age¶ (Ma)
Ec1 (231.2)a0.0014.7125.8041.6820.7715210257.30.740.10 ± 0.01**0.13 ± 0.01**
 b0.13121.15115.7337.08148.351747546.30.685.51 ± 0.288.09 ± 0.40
c11.1748.9316.0276.4452.6920311064.90.77460.80 ± 23.04597.86 ± 29.89
d2.120.301.000.300.5425313479.50.813790.37 ± 189.52**4666.69 ± 233.33**
e3.7459.6610.3013462.082188754.40.73227.29 ± 11.36312.49 ± 15.62
EC2 (201.8)a8.7587.5823.0997694.001568851.60.71267.41 ± 7.94311.94 ± 9.23
 b3.0859.704.92106162.131536640.90.64181.06 ± 6.58220.17 ± 7.97
c2.5546.0710.97121950.131749354.90.73153.64 ± 5.07178.67 ± 5.88
d2.9244.7112.4080048.591448549.00.70204.29 ± 7.40242.22 ± 8.76
e3.3679.834.69102082.171497946.80.68202.59 ± 6.67242.87 ± 7.97
Ec5a (144.9)a0.5010446692.002141829556.50.74231.88 ± 3.18323.75 ± 4.50
 b0.9026.114.2635.3427.1524310162.70.7694.74 ± 0.91124.09 ± 1.19
e1.6217.957.3026.1419.7117311062.60.76102.61 ± 0.95136.42 ± 1.26
f1.4611 320127110011 61937611775.90.800.17 ± 0.00**0.21 ± 0.00**
h4.4941.188.7046.0043.2736013283.10.82150.23 ± 1.25183.02 ± 1.51
Ec7 (104.0)a1.0926.723.8664.0527.7118410059.00.75112.16 ± 4.05129.08 ± 4.65
 b0.2417.822.9854.6118.591327845.30.6786.79 ± 5.18104.48 ± 6.23
c1.4630.774.5569.8231.921388950.60.71142.50 ± 5.03169.79 ± 5.98
d0.3321.012.8746.3221.741278346.80.6897.57 ± 5.61116.79 ± 6.71
e0.2818.064.1046.1119.081497745.90.6881.14 ± 4.6098.57 ± 5.58
Ec8 (201.3)b0.290.290.550.3524111871.10.79– ± –**– ± –**
 d4.6622.384.6553.0023.5422813578.10.81235.37 ± 1.88292.22 ± 2.32
f3.2228.7910.4710131.3719515784.00.82206.00 ± 17.00257.00 ± 22.00
g0.479.503.5444.7710.3919313675.40.80146.53 ± 1.98185.63 ± 2.50
i1.5613.596.9053.0015.2713812062.70.76217.14 ± 2.13297.47 ± 2.91
Ec81T (145.9)a0.6413.124.4640.2014.22197151240.40.9474.82 ± 0.5980.43 ± 0.64
 b0.3313.065.4146.7214.39124137194.90.9292.27 ± 1.11103.65 ± 1.25
c0.519.144.5746.6210.27173130207.80.93127.44 ± 1.15138.55 ± 1.25
d11.0192.4082.65108.61111.96180165249.70.94164.58 ± 1.23177.67 ± 1.33
e0.707.484.6239.928.62189135219.30.93156.59 ± 1.25169.31 ± 1.35
f0.5510.892.7733.7711.58174124201.00.93124.59 ± 1.21135.56 ± 1.31
h0.5012.634.3378.0713.74175138218.20.9379.67 ± 0.7786.38 ± 0.84
i0.7911.984.2253.4513.03239145245.30.94105.27 ± 0.93112.56 ± 1.00
j0.279.185.5350.1310.55169119193.60.9262.61 ± 0.7568.44 ± 0.82
k0.3118.265.2533.3819.5313297156.10.90113.52 ± 1.43126.84 ± 1.60
l0.6623.605.3779.8024.96178118195.00.92112.37 ± 1.07122.42 ± 1.17
m0.2111.685.4549.5113.02129109168.70.9166.65 ± 1.0374.31 ± 1.15
n0.2414.024.2859.0915.10113115168.00.9191.91 ± 1.34103.94 ± 1.51
o0.359.106.1953.4610.62103139182.70.92131.76 ± 1.51160.78 ± 1.84
p2.9238.625.3970.1839.97176122199.20.92197.95 ± 1.56215.20 ± 1.69
q1.3814.503.5955.9815.41175201281.80.95166.88 ± 1.28181.36 ± 1.39
r1.0284.3513.6871.0087.6513499159.80.9190.51 ± 0.79100.85 ± 0.88
s0.256.053.1312.266.8012399155.60.9077.43 ± 1.0586.99 ± 1.18
t1.8524.483.4769.6625.3812776128.50.88610.17 ± 6.18690.08 ± 6.94
u1.7417.523.8584.8018.52165120194.30.92271.03 ± 2.01295.59 ± 2.19
Ec12 (129.1)a3.5156.0030.6681264.0021410563.20.76101.63 ± 0.87133.65 ± 1.14
 b1.7110.4519.7758615.8018210661.60.76155.37 ± 1.38209.08 ± 1.85
d5.835.191.933.095.652318051.10.710.83 ± 1.76**1.16 ± 2.46**
e5.1417.9759.0044032.2720311366.30.78130.31 ± 1.03172.28 ± 1.37
Ec13 (220.3)a3.2517.103.2551118.4821811367.30.78210.66 ± 1.87270.67 ± 2.39
 b5.2419.302.0891220.8922412673.80.80278.20 ± 2.51348.96 ± 3.13
c2.6529.851.5698931.4118610360.50.75187.63 ± 1.74248.91 ± 2.29
d1.5654.009.80143358.001377644.60.67202.17 ± 2.04301.51 ± 3.01
e2.9629.144.5180931.181818652.10.72222.69 ± 1.96309.52 ± 2.71
EC14 (279.5)a0.8823.345.9268525.561776440.70.64208.00 ± 10.00255.00 ± 12.00
 b2.6421.371.3154322.331638651.30.71418.00 ± 19.00495.00 ± 23.00
c2.5622.384.1066724.1519110863.10.76238.88 ± 8.87272.00 ± 10.00
d3.7525.012.1256326.1919411466.00.77273.59 ± 9.98309.00 ± 11.00
e1.8027.772.4658729.051617646.00.68258.82 ± 9.68309.00 ± 12.00
Ec16 (250.3)b48.5947.481.6055349.00353166100.80.85510.55 ± 3.99596.45 ± 4.72
 d0.000.061.573.320.431156236.60.6035.41 ± 50.0865.57 ± 92.74
g2.2118.520.6126418.981897647.50.69290.60 ± 2.83415.81 ± 4.00
h2.0967.002.2061568.001998351.50.71257.94 ± 2.65358.14 ± 3.65
b1.9348.703.6542950.0815810257.80.74157.08 ± 1.23213.31 ± 1.66
EC17 (234.5)a1.4013.817.3165316.3116910359.30.75194.85 ± 8.37222.79 ± 9.57
 b1.2120.690.8574921.801869958.40.75182.65 ± 6.97211.08 ± 8.03
c0.9718.761.7891220.281676741.70.65277.00 ± 18.00336.00 ± 21.00
d6.9625.481.6774626.771366438.70.62256.19 ± 8.222.86 ± 0.09
e0.6112.651.4061813.731797043.70.66262.00 ± 21.00316.00 ± 25.00
Ec18 (222.4)c0.000.984.158.771.9511910052.80.720.62 ± 3.41**0.00 ± 0.00**
 e0.0031.0430.062.1738.1118014075.60.800.52 ± 0.20**0.65 ± 0.25**
f1.4149.0029.2381357.001517444.60.67195.42 ± 1.99292.23 ± 2.96
g1.801.576.812.161978351.40.710.39 ± 0.14**– ± –**
i14.6521.3014.7341525.27272200109.70.86249.32 ± 2.09292.82 ± 2.44
Ec19 (211.7)a5.0024.3912.2159027.97198126139.30.89196.73 ± 1.27221.91 ± 1.43
 b9.0643.856.0777446.21216126136.80.89232.45 ± 1.64261.69 ± 1.84
c9.8323.2511.6572026.8528916998.30.85214.61 ± 6.00259.21 ± 7.23
d1.6019.417.8566722.072168050.80.71204.47 ± 9.06231.00 ± 10.00
e8.2146.569.8096850.0323012875.10.80210.32 ± 5.92237.28 ± 6.67
Ec20 (212.7)166.4848.0030.92181.055.0021112170.70.79277.18 ± 2.42353.49 ± 3.07
 271.0439.2310.9226.941.791378950.40.7152.71 ± 0.5475.88 ± 0.78
3217.9867.0045843.517520110763.30.77326.62 ± 2.91440.30 ± 3.88
433.5529.723.2132.130.4723711267.80.78249.90 ± 2.43319.23 ± 3.08
452.5241.174.3116.342.1818210962.90.76156.92 ± 1.52206.65 ± 2.00
Ec21 (189.7)a10.2425.600.1640526.1332713785.00.82141.41 ± 1.08171.35 ± 1.31
 b23.8722.821.9746023.84510179114.10.87226.91 ± 1.72260.83 ± 1.97
c0.0019.378.648.921.4126612978.00.810.30 ± 5.70**0.40 ± 7.10**
f6.9025.642.1642626.66380222128.70.88179.31 ± 1.37203.67 ± 1.56
g3.5646.386.7747848.55380222128.70.88211.11 ± 1.70239.77 ± 1.93
Ec22 (195.4)a8.1224.111.3112224.5730516697.80.85214.38 ± 1.47253.49 ± 1.73
 e2.3622.181.0013522.5723811368.30.78130.04 ± 1.18166.22 ± 1.50
f4.6928.402.2114329.0926316895.50.84163.32 ± 1.28194.95 ± 1.52
g2.7837.5114.4415641.091807948.70.70297.36 ± 2.27423.86 ± 3.21
h4.0540.5515.7385.644.3518314678.30.81172.05 ± 1.19217.91 ± 1.50
Ec23 (194.4)a3.0042.942.5027743.8615510659.10.75216.93 ± 1.76292.90 ± 2.36
 b11.6344.201.2435244.91273178100.50.85261.91 ± 1.86309.35 ± 2.19
c2.5153.992.5748055.1718211163.90.77156.46 ± 1.25205.14 ± 1.63
d0.000.941.090.411.191459955.30.73– ± –**– ± –**
e2.3738.343.7224039.5018810159.60.75142.44 ± 1.11189.98 ± 1.48
  • * Mean is the arithmetic mean age for each sample calculated from ages given in the two rightmost columns, except that those with ** represent grain ages that have been excluded for being either <1 Ma or >1 Ga.

  • eU = [U] + 0.235[Th].

  • r' is the spherical equivalent radius.

  • § Ft is the calculated correction factor from Farley et al. (1996).

  • ¶Corrected age is calculated from Measured Age/Ft.