Table 1 (continued). 40Ar/39Ar Dating of biotites from Leg 165 tephra layers.
Core,
section,
interval (cm) |
Analysis
number |
40Ar/39Ar
|
38Ar/39Ar
|
37Ar/39Ar
|
36Ar/39Ar
|
39Ar
|
Atm
(%) |
40Ar*/39Ar
|
Age
(Ma) |
±
(m.y.)
|
wi
|
xi*wi
|
Mean
|
Error
|
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
165-999B- | ||||||||||||||
7R-CC, 13-14 | 1 | 6.865 | 0.123 | 0.008 | 0.0024 | 64.63 | 4.44 | 24.56 | 9.67 | 0.01 | 0.3 | |||
7R-CC, 13-14 | 2 | 3.354 | 0.091 | 0.000 | 0.0019 | 100.00 | 3.35 | 18.60 | 12.15 | 0.01 | 0.1 | |||
7R-CC, 13-14 | 3 | 5.232 | 0.182 | 0.003 | 0.0116 | 80.53 | 4.21 | 23.34 | 2.05 | 0.24 | 5.6 | |||
7R-CC, 13-14 | 4 | 5.558 | 0.205 | 0.004 | 0.0044 | 76.08 | 4.23 | 23.42 | 5.29 | 0.04 | 0.8 | |||
7R-CC, 13-14 | 5 | 4.611 | 0.070 | 0.000 | 0.0054 | 100.00 | 4.61 | 25.52 | 6.77 | 0.02 | 0.6 | |||
23.44 | 1.79 | |||||||||||||
15R-2, 45-46 | 1 | 5.253 | 0.117 | 0.000 | 0.0042 | 100.00 | 5.25 | 29.05 | 5.58 | 0.03 | 0.9 | |||
15R-2, 45-46 | 2 | 5.415 | 0.110 | 0.002 | 0.0059 | 90.67 | 4.91 | 27.17 | 4.02 | 0.06 | 1.7 | |||
15R-2, 45-46 | 3 | 5.754 | 0.126 | 0.002 | 0.0189 | 91.84 | 5.28 | 29.22 | 1.39 | 0.51 | 15.0 | |||
15R-2, 45-46 | 4 | 4.982 | 0.111 | 0.002 | 0.0046 | 87.15 | 4.34 | 24.04 | 5.09 | 0.04 | 0.9 | |||
15R-2, 45-46 | 5 | 5.150 | 0.111 | 0.003 | 0.0116 | 85.19 | 4.39 | 24.29 | 2.04 | 0.24 | 5.8 | |||
15R-2, 45-46 | 6 | 5.150 | 0.112 | 0.000 | 0.0075 | 100.00 | 5.15 | 28.49 | 3.13 | 0.10 | 2.9 | |||
15R-2, 45-46 | 7 | 5.150 | 0.113 | 0.000 | 0.0124 | 100.00 | 5.15 | 28.48 | 1.44 | 0.48 | 13.7 | |||
15R-2, 45-46 | 8 | 4.940 | 0.119 | 0.004 | 0.0089 | 73.25 | 3.62 | 20.06 | 2.65 | 0.14 | 2.8 | |||
27.21 | 0.79 | |||||||||||||
47R-6, 4-5 | 1 | 16.275 | 0.057 | 0.000 | 0.0006 | 100.00 | 16.27 | 88.52 | 38.59 | 0.00 | 0.1 | |||
47R-6, 4-5 | 2 | 10.245 | 0.040 | 0.005 | 0.0037 | 84.33 | 8.64 | 47.53 | 6.34 | 0.02 | 1.2 | |||
48.61 | 1.15 | |||||||||||||
48R-3, 6-7 | 1 | 10.377 | 0.109 | 0.002 | 0.0048 | 94.07 | 9.76 | 53.62 | 4.94 | 0.04 | 2.2 | |||
48R-3, 6-7 | 2 | 9.351 | 0.106 | 0.000 | 0.0091 | 100.00 | 9.35 | 51.39 | 2.71 | 0.14 | 7.0 | |||
48R-3, 6-7 | 3 | 9.728 | 0.107 | 0.000 | 0.0081 | 100.00 | 9.73 | 53.43 | 4.49 | 0.05 | 2.7 | |||
48R-3, 6-7 | 4 | 9.686 | 0.101 | 0.000 | 0.0039 | 100.00 | 9.69 | 53.20 | 6.12 | 0.03 | 1.4 | |||
48R-3, 6-7 | 5 | 9.149 | 0.106 | 0.000 | 0.0036 | 100.00 | 9.15 | 50.29 | 6.48 | 0.02 | 1.2 | |||
48R-3, 6-7 | 6 | 9.744 | 0.111 | 0.002 | 0.0042 | 92.86 | 9.05 | 49.75 | 8.52 | 0.01 | 0.7 | |||
48R-3, 6-7 | 7 | 10.040 | 0.107 | 0.000 | 0.0031 | 100.00 | 10.04 | 55.12 | 7.61 | 0.02 | 1.0 | |||
48R-3, 6-7 | 8 | 14.070 | 0.104 | 0.014 | 0.0035 | 70.41 | 9.91 | 54.40 | 6.56 | 0.02 | 1.3 | |||
48R-3, 6-7 | 9 | 9.966 | 0.099 | 0.001 | 0.0190 | 96.88 | 9.66 | 53.04 | 1.67 | 0.36 | 19.0 | |||
48R-3, 6-7 | 10 | 9.473 | 0.101 | 0.003 | 0.0034 | 90.75 | 8.60 | 47.30 | 6.99 | 0.02 | 1.0 | |||
48R-3, 6-7 | 11 | 9.832 | 0.108 | 0.000 | 0.0103 | 100.00 | 9.83 | 54.00 | 2.64 | 0.14 | 7.7 | |||
48R-3, 6-7 | 12 | 9.429 | 0.108 | 0.000 | 0.0048 | 100.00 | 9.43 | 51.81 | 5.07 | 0.04 | 2.0 | |||
48R-3, 6-7 | 13 | 12.003 | 0.101 | 0.000 | 0.0047 | 100.00 | 12.00 | 65.70 | 5.35 | 0.03 | 2.3 | |||
48R-3, 6-7 | 14 | 9.617 | 0.101 | 0.001 | 0.0075 | 95.90 | 9.22 | 50.69 | 3.23 | 0.10 | 4.9 | |||
48R-3, 6-7 | 15 | 10.489 | 0.099 | 0.004 | 0.0023 | 87.72 | 9.20 | 50.58 | 10.15 | 0.01 | 0.5 | |||
48R-3, 6-7 | 16 | 9.607 | 0.089 | 0.005 | 0.0021 | 85.35 | 8.20 | 45.14 | 11.66 | 0.01 | 0.3 | |||
48R-3, 6-7 | 17 | 10.351 | 0.101 | 0.003 | 0.0063 | 90.96 | 9.42 | 51.74 | 3.73 | 0.07 | 3.7 | |||
48R-3, 6-7 | 18 | 9.030 | 0.096 | 0.004 | 0.0048 | 86.37 | 7.80 | 42.96 | 4.90 | 0.04 | 1.8 | |||
48R-3, 6-7 | 19 | 9.706 | 0.089 | 0.000 | 0.0028 | 100.00 | 9.71 | 53.31 | 8.43 | 0.01 | 0.7 | |||
48R-3, 6-7 | 20 | 8.934 | 0.086 | 0.000 | 0.0026 | 100.00 | 8.93 | 49.13 | 8.86 | 0.01 | 0.6 | |||
52.47 | 0.92 | |||||||||||||
165-1000A- | ||||||||||||||
16H-6, 21-22 | 1 | 2.252 | 0.104 | -0.002 | 0.002 | 32.38 | 74.48 | 1.678 | 8.94 | 0.86 | 1.35 | 12.0 | ||
16H-6, 21-22 | 2 | 2.028 | 0.088 | -0.001 | 0.005 | 48.24 | 30.22 | 0.613 | 3.27 | 0.43 | 5.30 | 17.3 | ||
16H-6, 21-22 | 3 | 3.424 | 0.096 | -0.003 | 0.002 | 12.55 | 82.67 | 2.83 | 15.05 | 1.55 | 0.41 | 6.2 | ||
16H-6, 21-22 | 4 | 2.071 | 0.103 | 0.001 | 0.004 | 50.05 | 36.53 | 0.756 | 4.04 | 0.38 | 6.83 | 27.6 | ||
16H-6, 21-22 | 5 | 1.362 | 0.096 | -0.003 | 0.000 | 29.81 | 93.89 | 1.279 | 6.82 | 0.68 | 2.18 | 14.9 | ||
16H-6, 21-22 | 6 | 0.884 | 0.100 | 0.000 | 0.000 | 19.37 | 85.51 | 0.756 | 4.03 | 0.98 | 1.04 | 4.2 | ||
4.80 | 0.24 | |||||||||||||
28H-1, 88-89 | 1 | 1.382 | 0.083 | 0.006 | 0.000 | 66.03 | 94.56 | 1.307 | 6.96 | 0.30 | 11.05 | 77.0 | ||
28H-1, 88-89 | 2 | 1.452 | 0.088 | 0.006 | 0.000 | 64.36 | 94.69 | 1.375 | 7.33 | 0.30 | 11.41 | 83.6 | ||
28H-1, 88-89 | 3 | 1.591 | 0.089 | 0.006 | 0.000 | 63.82 | 95.11 | 1.513 | 8.06 | 0.32 | 9.72 | 78.4 | ||
28H-1, 88-89 | 4 | 1.364 | 0.085 | 0.027 | 0.001 | 18.03 | 69.71 | 0.950 | 5.07 | 1.03 | 0.95 | 4.8 | ||
28H-1, 88-89 | 5 | 1.565 | 0.082 | 0.002 | 0.000 | 66.53 | 97.62 | 1.528 | 8.14 | 0.44 | 5.07 | 41.3 | ||
7.46 | 0.16 | |||||||||||||
165-1000B- | ||||||||||||||
14R-2, 139-140 | 1 | 3.695 | 0.107 | 0.011 | 0.001 | 27.20 | 95.06 | 3.512 | 18.66 | 0.76 | 1.73 | 32.2 | ||
14R-2, 139-140 | 2 | 3.471 | 0.100 | 0.000 | 0.000 | 25.02 | 97.14 | 3.371 | 17.91 | 0.80 | 1.57 | 28.1 | ||
14R-2, 139-140 | 3 | 4.342 | 0.108 | 0.007 | 0.004 | 15.87 | 72.99 | 3.169 | 16.85 | 1.21 | 0.69 | 11.6 | ||
14R-2, 139-140 | 4 | 3.634 | 0.109 | 0.006 | 0.000 | 33.85 | 97.98 | 3.561 | 18.92 | 0.69 | 2.12 | 40.2 | ||
14R-2, 139-140 | 5 | 3.555 | 0.112 | 0.006 | 0.000 | 29.38 | 97.62 | 3.470 | 18.44 | 0.72 | 1.92 | 35.4 | ||
14R-2, 139-140 | 6 | 3.451 | 0.095 | 0.004 | 0.000 | 29.10 | 97.53 | 3.366 | 17.89 | 0.89 | 1.26 | 22.5 | ||
18.31 | 0.33 | |||||||||||||
16R-5, 84-85 | 1 | 3.391 | 0.108 | -0.002 | 0.000 | 57.97 | 98.74 | 3.348 | 17.79 | 0.53 | 3.59 | 63.9 | ||
16R-5, 84-85 | 2 | 3.583 | 0.078 | 0.000 | 0.000 | 50.61 | 98.63 | 3.534 | 18.77 | 0.48 | 4.37 | 82.1 | ||
16R-5, 84-85 | 3 | 3.546 | 0.090 | 0.001 | 0.000 | 62.65 | 98.88 | 3.506 | 18.63 | 0.43 | 5.53 | 103.1 | ||
16R-5, 84-85 | 4 | 3.357 | 0.088 | 0.001 | 0.000 | 115.30 | 99.36 | 3.336 | 17.73 | 0.75 | 1.77 | 31.3 | ||
16R-5, 84-85 | 5 | 3.196 | 0.163 | 0.002 | 0.000 | 74.19 | 98.95 | 3.162 | 16.81 | 0.35 | 8.15 | 136.9 | ||
16R-5, 84-85 | 6 | 3.256 | 0.082 | 0.002 | 0.000 | 76.82 | 99.01 | 3.224 | 17.14 | 0.33 | 9.39 | 161.0 | ||
16R-5, 84-85 | 7 | 3.212 | 0.108 | 0.002 | 0.000 | 100.83 | 99.23 | 3.188 | 16.94 | 0.93 | 1.14 | 19.4 | ||
16R-5, 84-85 | 8 | 3.282 | 0.095 | 0.005 | 0.000 | 61.53 | 98.77 | 3.241 | 17.23 | 0.35 | 8.29 | 142.7 | ||
16R-5, 84-85 | 9 | 3.300 | 0.103 | 0.008 | 0.000 | 37.29 | 97.98 | 3.233 | 17.18 | 0.52 | 3.71 | 63.7 | ||
17.50 | 0.15 | |||||||||||||
19R-2, 99-101 | 1 | 3.284 | 0.209 | 0.007 | 0.000 | 55.55 | 98.64 | 3.239 | 17.22 | 0.74 | 1.81 | 31.2 | ||
19R-2, 99-101 | 2 | 3.088 | 0.211 | 0.009 | 0.000 | 35.90 | 97.76 | 3.019 | 16.05 | 0.67 | 2.20 | 35.4 | ||
19R-2, 99-101 | 3 | 3.443 | 0.223 | 0.005 | 0.000 | 42.97 | 98.32 | 3.385 | 17.99 | 0.48 | 4.38 | 78.8 | ||
19R-2, 99-101 | 4 | 3.152 | 0.219 | 0.016 | 0.000 | 20.34 | 96.13 | 3.030 | 16.11 | 0.97 | 1.06 | 17.0 | ||
19R-2, 99-101 | 5 | 3.184 | 0.219 | 0.007 | 0.000 | 38.88 | 97.99 | 3.120 | 16.59 | 0.60 | 2.73 | 45.3 | ||
19R-2, 99-101 | 6 | 3.534 | 0.213 | -0.002 | 0.000 | 49.66 | 98.59 | 3.484 | 18.51 | 0.50 | 3.95 | 73.1 | ||
19R-2, 99-101 | 7 | 3.557 | 0.218 | 0.001 | 0.000 | 42.45 | 98.36 | 3.499 | 18.59 | 0.86 | 1.35 | 25.2 | ||
19R-2, 99-101 | 8 | 3.459 | 0.211 | 0.008 | 0.000 | 33.95 | 97.89 | 3.386 | 17.99 | 0.65 | 2.40 | 43.2 | ||
19R-2, 99-101 | 9 | 3.665 | 0.217 | 0.003 | 0.005 | 44.68 | 62.11 | 2.28 | 12.12 | 0.44 | 5.14 | 62.2 | ||
19R-2, 99-101 | 10 | 3.520 | 0.211 | 0.001 | 0.000 | 114.99 | 99.39 | 3.498 | 18.59 | 0.55 | 3.25 | 60.5 | ||
19R-2, 99-101 | 11 | 3.320 | 0.212 | 0.002 | 0.000 | 92.22 | 99.19 | 3.293 | 17.50 | 0.68 | 2.19 | 38.4 | ||
19R-2, 99-101 | 12 | 3.618 | 0.219 | 0.003 | 0.000 | 75.98 | 99.10 | 3.586 | 19.05 | 0.76 | 1.73 | 33.0 | ||
19R-2, 99-101 | 13 | 3.629 | 0.209 | 0.001 | 0.000 | 91.31 | 99.25 | 3.602 | 19.13 | 0.66 | 2.27 | 43.5 | ||
17.02 | 0.17 | |||||||||||||
165-1001A- | ||||||||||||||
26R-2, 63-64 | 1 | 12.237 | 0.078 | -0.018 | 0.001 | 7.62 | 97.34 | 11.911 | 62.51 | 3.12 | 0.10 | 6.4 | ||
26R-2, 63-64 | 2 | 12.007 | 0.079 | -0.008 | 0.002 | 15.63 | 96.03 | 11.530 | 60.55 | 1.98 | 0.25 | 15.4 | ||
26R-2, 63-64 | 3 | 10.605 | 0.085 | 0.009 | 0.002 | 4.30 | 94.56 | 10.028 | 52.77 | 4.59 | 0.05 | 2.5 | ||
60.14 | 1.57 | |||||||||||||
36R-3, 70-71 | 1 | 21.041 | 0.094 | -0.008 | 0.015 | 12.24 | 78.31 | 16.48 | 85.91 | 3.01 | 0.11 | 9.5 | ||
36R-3, 70-71 | 2 | 19.788 | 0.104 | -0.001 | 0.016 | 27.33 | 75.67 | 14.974 | 78.24 | 2.25 | 0.20 | 15.5 | ||
36R-3, 70-71 | 3 | 23.395 | 0.120 | -0.001 | 0.028 | 11.63 | 64.42 | 15.072 | 78.74 | 2.51 | 0.16 | 12.5 | ||
36R-3, 70-71 | 4 | 20.707 | 0.108 | 0.008 | 0.016 | 22.07 | 77.19 | 15.983 | 83.39 | 1.95 | 0.26 | 21.8 | ||
36R-3, 70-71 | 5 | 19.749 | 0.100 | 0.017 | 0.017 | 14.72 | 73.96 | 14.607 | 76.36 | 1.76 | 0.32 | 24.7 | ||
36R-3, 70-71 | 6 | 16.086 | 0.119 | 0.018 | 0.012 | 12.90 | 77.27 | 12.429 | 65.18 | 2.00 | 0.25 | 16.2 | ||
36R-3, 70-71 | 7 | 19.251 | 0.119 | 0.025 | 0.016 | 12.76 | 75.74 | 14.582 | 76.23 | 2.29 | 0.19 | 14.5 | ||
36R-3, 70-71 | 8 | 16.926 | 0.091 | 0.009 | 0.012 | 39.39 | 79.71 | 13.492 | 70.65 | 1.14 | 0.77 | 54.7 | ||
74.78 | 0.66 | |||||||||||||
165-1001B- | ||||||||||||||
6R-3, 130-131 | 1 | 15.762 | 0.192 | 0.024 | 0.001 | 6.28 | 97.49 | 15.366 | 80.25 | 3.45 | 0.08 | 6.8 | ||
6R-3, 130-131 | 2 | 16.520 | 0.189 | 0.058 | 0.002 | 3.88 | 96.13 | 15.880 | 82.87 | 5.22 | 0.04 | 3.0 | ||
81.04 | 2.88 |
Notes: %Atm = 100*[(40Ar/39Ar-295.5*36Ar/39Ar)/40Ar/39Ar]. 40Ar*/39Ar = the ratio of the radiogenic isotope of argon (40Ar) to the 39Ar produced in the reactor from potassium. wi = the weighting used in the weighted mean and is the inverse of variance on each measurement. xi*wi = the weighting multiplied by the measured age of each measurement.