242 / 352
207
Pb
a
U
b
Pb
b
Th
b 206
Pbc
c 207
Pb
d
±2s
206
Pb
d
±2s ȡ
e
207
Pb
d
±2s
206
Pb
f
±2s
207
Pb
f
±2s
207
Pb
f
±2s Conc.
g
(cps) (ppm) (ppm)
U (%)
235
U (%)
238
U (%) (rho)
206
Pb (%)
238
U (Ma)
235
U (Ma)
206
Pb (Ma) (%)
Grain
A340
3115 148 17 0.80 b.d.
0.8972 2.6 0.1044 0.9 0.36 0.06233 2.4 640 6 650 12 685 51 93
A199
867 37 4 0.74 0.4 0.9746 4.2 0.1128 1.4 0.33 0.06268 3.9 689 9 691 21 697 84 99
A257
7255 64 13 0.42 0.0 2.230 1.9 0.1999 0.9 0.49 0.08090 1.6 1175 10 1190 13 1219 32 96
A361 11592 100 21 0.49 0.0 2.232 1.9 0.1984 0.8 0.45 0.08161 1.7 1167 9 1191 13 1236 33 94
A318
2487 19 6 1.95 b.d.
2.684 3.2 0.2260 1.2 0.38 0.08613 3.0 1314 15 1324 24 1341 58 98
A248 52371 194 66 0.26 b.d.
5.502 1.0 0.3357 0.7 0.65 0.1189 0.8 1866 11 1901 9 1939 14 96
A235 15770 93 36 0.91 0.1 5.756 1.8 0.3328 0.9 0.54 0.1254 1.5 1852 15 1940 15 2035 26 91
A256
9797 63 26 1.24 b.d.
5.804 1.5 0.3416 0.9 0.59 0.1232 1.3 1894 15 1947 13 2004 22 95
A220 22523 75 36 1.87 0.0 5.951 1.3 0.3534 0.7 0.56 0.1221 1.0 1951 12 1969 11 1988 18 98
A246 26810 186 72 0.81 b.d.
6.012 1.1 0.3403 0.7 0.67 0.1281 0.8 1888 12 1978 9 2072 14 91
A311 12040 38 15 0.78 0.0 6.141 1.7 0.3477 1.1 0.66 0.1281 1.3 1924 18 1996 15 2072 22 93
A228 19634 131 56 1.09 b.d.
6.152 1.3 0.3536 0.8 0.59 0.1262 1.1 1952 13 1998 11 2045 19 95
A221 72693 222 88 0.61 0.0 6.177 1.1 0.3611 0.8 0.76 0.1241 0.7 1987 14
2001 10 2016 13 99
A266 76715 486 199 0.76 0.0 6.211 1.1 0.3635 0.9 0.79 0.1239 0.7 1999 15 2006 10 2013 12 99
A268 11744 37 16 1.08 0.1 6.253 1.6 0.3509 0.8 0.50 0.1292 1.4 1939 13 2012 14 2088 24 93
A322
7410 48 22 1.36 0.1 6.256 2.0 0.3654 0.9 0.46 0.1242 1.8 2008 16 2012 18 2017 31 100
A245
10090 32 13 0.71 0.1
6.261 1.7 0.3599 1.0 0.56 0.1262 1.4 1982 17 2013 15 2045 25 97
A207
9760 31 13 1.15 b.d.
6.302 1.7 0.3683 0.8 0.46 0.1241 1.5 2022 14 2019 15 2016 27 100
A267 18776 121 56 1.49 0.1 6.322 1.3 0.3582 0.7 0.55 0.1280 1.1 1974 12 2022 12 2071 20 95
A349 34883 107 56 2.31 0.1 6.334 1.3 0.3667 0.8 0.63 0.1253 1.0 2014 15 2023 12 2033 18 99
A253 10180 32 12 0.47 0.0 6.338 1.7 0.3571 1.0 0.57 0.1287 1.4 1969 17 2024 15 2080 25 95
A270 19367 117 46 0.82 b.d.
6.349 1.6 0.3470 1.0 0.64 0.1327 1.2 1920 16 2025 14 2134 21 90
A367 17336 52 22 0.85 1.7 6.359 2.0 0.3564 0.8 0.41 0.1294 1.9 1965 14 2027 18 2090 33 94
A351 11254 34 14 0.87 0.0 6.386 1.8 0.3577 0.9 0.48 0.1295 1.6 1971 15 2030 16 2091 28 94
A232 10354 68 30 1.11 b.d.
6.411 1.4 0.3673 0.7 0.51 0.1266 1.2 2017 12 2034 12 2051 21 98
A224 18004 24 10 0.85 b.d.
6.412 1.2 0.3571 0.7 0.55 0.1302 1.0 1969 11 2034 11 2101 18 94
A302 33401 105 44 0.77 0.0 6.417 1.2 0.3709 0.9 0.70 0.1255 0.9 2034 15 2035 11 2036 16 100
A215 10102 67 27 0.74 b.d.
6.424 1.6 0.3594 0.9 0.55 0.1296 1.4 1980 16 2036 15 2093 24 95
A326 11364 70 31 1.14 b.d.
6.442 1.6 0.3637 0.9 0.57 0.1285 1.3 2000 16 2038 14 2077 24 96
A210 10553 33 16 1.58 0.0 6.499 1.8 0.3696 1.0 0.52 0.1275 1.6 2027 17 2046 16 2064 28 98
A237
7738 50 23 1.20 0.0 6.502 2.0 0.3736 1.0 0.51 0.1262 1.7 2046 18 2046 17 2046 30 100
A334 21884 142 64 1.37 b.d.
6.506 1.3 0.3641 0.7 0.59 0.1296 1.0 2002 13 2047 11 2093 18 96
A229
4547 14 6 0.97 0.0 6.516 2.3 0.3738 1.3 0.54 0.1264 2.0 2047 22 2048 21 2049 35 100
A301
9831 28 12 0.99 b.d.
6.518 1.5 0.3595 0.8 0.53 0.1315 1.3 1980 14 2048 14 2118 23 93
A310
9337 28 14 1.68 b.d.
6.575 1.6 0.3670 1.0 0.62 0.1299 1.3 2015 17 2056 14 2097 22 96
A222
7915 25 10 0.89 0.0 6.578 1.8 0.3672 1.0 0.58 0.1299 1.4 2016 18 2056 16 2097 25 96
A209
5198 16 7 1.43 0.0 6.609 1.8 0.3684 0.9 0.48 0.1301 1.6 2022 15 2061 16 2100 28 96
A181 14032 43 18 0.92 b.d.
6.648 1.4 0.3706 0.9 0.68 0.1301 1.0 2032 16 2066 12 2100 18 97
A261 10788 31 14 1.16 b.d.
6.672 1.7 0.3629 0.9 0.52 0.1334 1.5 1996 15 2069 15 2143 25 93
A208
6958 42 19 1.03 0.0 6.674 1.9 0.3715 1.0 0.55 0.1303 1.6 2037 18 2069 17 2102 28 97
A274
8869 55 25 1.31 b.d.
6.754 1.4 0.3660 0.8 0.58 0.1338 1.1 2011 14 2080 12 2149 20 94
A305
7400 22 10 1.02 b.d.
6.774 2.0 0.3795 0.7 0.34 0.1294 1.9 2074 12 2082 18 2090 33 99
A255
9722 60 29 1.30 0.0 6.804 1.7 0.3817 0.7 0.43 0.1293 1.5 2084 13 2086 15 2088 27 100
A192
3470 22 10 0.91 0.0 6.811 2.1 0.3776 1.2 0.57 0.1308 1.8 2065 22 2087 19 2109 31 98
A308
8913 26 12 1.07 0.1 6.862 1.7 0.3820 1.0 0.60 0.1303 1.3 2086 18 2094 15 2102 24 99
A247
5344 15 6 0.68 b.d.
6.900 2.0 0.3769 0.8 0.39 0.1328 1.9 2062 14 2099 18 2135 33 97
A323 11010 33 14 0.77 b.d.
6.913 1.5 0.3774 0.9 0.62 0.1328 1.2 2064 16 2100 13 2136 20 97
A193
9523 57 27 1.22 b.d.
6.949 1.8 0.3836 1.0 0.58 0.1314 1.4 2093 19 2105 16 2117 25 99
A345
9110 26 12 1.33 0.0 6.990 1.6 0.3822 0.6 0.39 0.1326 1.5 2087 11 2110 15 2133 26 98
A294 12057 33 14 0.72 0.1 7.011 1.6 0.3732 0.9 0.55 0.1362 1.3 2044 15 2113 14 2180 23 94
A259 51983 348 170 1.28 0.1 7.022 2.0 0.4050 1.9 0.92 0.1257 0.8 2192 35 2114 18 2039 14 107
A362 17740 50 22 0.71 0.0 7.110 1.5 0.3829 0.7 0.43 0.1347 1.4 2090 12 2125 14 2160 24 97
A236 10768 62 26 0.61 b.d.
7.121 1.5 0.3856 0.9 0.58 0.1339 1.2 2102 16 2127 13 2150 21 98
A348 19560 126 54 0.50 0.3 7.153 2.1 0.4021 1.6 0.78 0.1290 1.3 2179 30 2131 19 2085 24 104
A191 32382 86 43 1.51 0.0 7.509 1.2 0.3866 0.8 0.61 0.1409 1.0 2107 14 2174 11 2238 17 94
A314 20371 52 25 0.97 0.2 7.770 1.2 0.4065 0.7 0.62 0.1386 0.9 2199 14 2205 11 2210 16 99
A206 57681 138 57 0.30 0.1 7.808 1.0 0.3948 0.7 0.67 0.1434 0.7 2145 12 2209 9 2269 13 95
A324 22474 57 25 0.46 b.d.
8.031 1.1 0.4016 0.7 0.65 0.1450 0.9 2176 14 2235 10 2288 15 95
A213 71345 159 73 0.37 0.1 8.551 1.3 0.4266 1.0 0.79 0.1454 0.8 2290 20 2291 12 2292 14 100
A185 62563 117 62 0.80 0.0 10.53 1.1 0.4541 0.7 0.66 0.1681 0.8 2414 14 2482 10 2539 14 95
A182 47475 174 90 0.49 0.0 10.69 1.1 0.4633 0.8 0.68 0.1674 0.8 2454 15 2497 10 2531 14 97
A200 114268 412 216 0.43 0.0 10.89 1.0 0.4767 0.8 0.78 0.1656 0.6 2513 17 2514 10 2514 11 100
A273 53807 204 102 0.34 b.d.
10.89 1.1 0.4646 0.8 0.71 0.1700 0.8 2460 16 2514 10 2557 13 96
A309 64673 238 122 0.46 0.1 10.92 1.1 0.4618 0.8 0.70 0.1714 0.8 2448 15 2516 10 2571 13 95
226