281 / 352
265
207
Pb
a
U
b
Pb
b
Th
b 206
Pbc
c 207
Pb
d
±2
V
206
Pb
d
±2
V
ȡ
e
207
Pb
d
±2
V
206
Pb
f
±2
V
207
Pb
f
±2
V
207
Pb
f
±2
V
Conc.
(cps) (ppm) (ppm)
U (%)
235
U (%)
238
U (%) (rho)
206
Pb (%)
238
U (Ma)
235
U (Ma)
206
Pb (Ma) (%)
Grain
A096 17830 113 55 1.48 b.d.
6.9020 1.4 0.3857 0.7 0.55 0.1298 1.1 2103 13 2099 12 2095 20 100
A077 14484 43 20 0.99 b.d.
6.9840 1.3 0.3832 0.7 0.54 0.1322 1.1 2091 12 2109 11 2127 19 98
A111 59717 352 182 1.64 b.d.
7.0970 1.3 0.3891 1.0 0.80 0.1323 0.8 2119 18 2124 11 2128 13 100
A011 59006 263 110 0.48 0.1 7.7220 1.2 0.3840 0.8 0.70 0.1458 0.8 2095 15 2199 11 2298 14 91
A162 193691 1041 420 0.13 0.1 8.0140 1.1 0.3960 0.8 0.72 0.1468 0.8 2151 15 2233 10 2308 14 93
A169 141858 352 148 0.11 0.0 8.3560 1.0 0.4155 0.8 0.80 0.1458 0.6 2240 16 2270 9 2298 10 97
A112 126835 622 255 0.02 0.0 8.6550 1.0 0.4084 0.7 0.68 0.1537 0.7 2208 13 2302 9 2388 12 92
A099 82252 387 171 0.28 0.1 8.6710 1.0 0.4196 0.7 0.69 0.1499 0.8 2259 14 2304 10 2345 13 96
A081 88144 198 85 0.11 0.2 8.9230 1.4 0.4205 1.1 0.75 0.1539 0.9 2263 20 2330 13 2390 16 95
A175 72625 145 66 0.15 0.0 9.6430 1.1 0.4369 0.8 0.71 0.1601 0.8 2337 16 2401 11 2457 14 95
A158 113353 236 108 0.29 0.0 9.7430 0.9 0.4273 0.7 0.73 0.1653 0.6 2294 13 2411 9 2511 11 91
A152 72287 136 60 0.14 0.0 9.7430 1.4 0.4217 0.9 0.61 0.1675 1.1 2268 17 2411 13 2533 19 90
A072 87374 183 85 0.12 b.d.
9.8210 1.1 0.4503 0.8 0.71 0.1582 0.8 2397 16 2418 10 2436 13 98
A174 82762 176 92 1.00 0.0 9.8250 1.2 0.4352 1.0 0.85 0.1637 0.6 2329 20 2419 11 2494 10 93
A140 84360 165 78 0.38 0.0 10.1200 1.0 0.4319 0.7 0.77 0.1699 0.6 2314 14 2446 9 2556 10 91
A159 94238 213 100 0.08 b.d. 10.1700 1.8 0.4619 1.3 0.76 0.1597 1.2 2448 27 2450 16 2453 19 100
A177 68721 132 63 0.42 0.1 10.3200 1.1 0.4345 0.7 0.66 0.1722 0.8 2326 14 2464 10 2579 13 90
A114 146130 288 164 0.96 0.4 10.3200 1.6 0.4784 1.4 0.87 0.1565 0.8 2520 29 2464 15 2418 13 104
A133 46703 92 48 0.59 0.0 10.3300 1.2 0.4611 0.8 0.68 0.1624 0.9 2445 17 2465 11 2481 15 99
A055 60869 382 189 0.24 0.0 10.6000 1.5 0.4702 1.2 0.80 0.1635 0.9 2484 25 2489 14 2492 16 100
A078 40643 157 83 0.75 0.1 10.6000 1.1 0.4519 0.7 0.60 0.1702 0.9 2403 13 2489 10 2560 15 94
A168 56783 112 60 0.62 0.0 10.8000 1.1 0.4786 0.6 0.56 0.1637 0.9 2521 13 2506 10 2494 15 101
A010 47138 152 79 0.50 0.0 10.9400 0.9 0.4652 0.6 0.67 0.1706 0.7 2462 12 2518 9 2564 11 96
A028 34393 225 125 0.68 0.0 11.0300 1.5 0.4902 1.0 0.65 0.1631 1.1 2572 21 2525 14 2489 19 103
A094 63572 110 53 0.21 b.d. 11.0400 1.0 0.4495 0.7 0.66 0.1782 0.8 2393 14 2527 10 2636 13 91
A084 62599 111 65 1.24 0.0 11.1700 1.0 0.4549 0.7 0.71 0.1781 0.7 2417 15 2538 10 2636 12 92
A023 39244 115 77 1.84 0.1 11.2000 1.1 0.4802 0.8 0.73 0.1691 0.7 2528 17 2540 10 2549 12 99
A129 59465 224 119 0.70 0.0 11.2200 1.0 0.4607 0.7 0.65 0.1766 0.8 2443 14 2541 10 2621 13 93
A083 203698 336 164 0.12 0.0 11.3900 1.2 0.4668 0.9 0.78 0.1770 0.7 2470 19 2556 11 2625 12 94
A153 117410 436 220 0.33 0.0 11.4500 0.9 0.4652 0.7 0.73 0.1786 0.6 2462 14 2561 8 2640 10 93
A039 27086 80 44 0.70 0.1 11.4700 1.7 0.4680 1.2 0.70 0.1778 1.2 2475 24 2562 16 2633 20 94
A025 63468 184 98 0.51 0.2 11.5200 1.2 0.4767 0.8 0.70 0.1752 0.8 2513 17 2566 11 2608 14 96
A065 70607 215 112 0.48 0.1 11.5500 1.1 0.4676 0.9 0.78 0.1792 0.7 2473 18 2569 10 2645 11 93
A073 77483 277 148 0.57 0.1 11.5900 1.0 0.4685 0.7 0.71 0.1793 0.7 2477 15 2571 10 2647 12 94
A082 109583 174 94 0.64 b.d. 11.6100 1.1 0.4759 0.9 0.79 0.1769 0.7 2509 19 2573 11 2624 12 96
A134 103814 352 185 0.46 0.0 11.6400 1.0 0.4726 0.8 0.75 0.1786 0.7 2495 16 2576 9 2640 11 95
A132 75875 209 113 0.65 0.0 11.6600 1.1 0.4766 0.8 0.68 0.1774 0.8 2512 16 2577 11 2628 14 96
A127 74128 133 73 0.66 0.0 11.9100 1.3 0.4761 1.0 0.79 0.1814 0.8 2510 21 2597 12 2666 13 94
A027 77945 482 261 0.25 0.1 12.0000 1.7 0.5092 1.3 0.80 0.1709 1.0 2653 29 2604 16 2567 17 103
A051 82134 441 248 0.62 0.0 12.0700 1.4 0.4863 1.2 0.88 0.1800 0.7 2555 25 2610 13 2653 11 96
A137 1
10086 190 100 0.30
0.0 12.0800 1.0 0.4880 0.7 0.76 0.1796 0.6 2562 15 2611 9 2649 10 97
A054 155341 868 468 0.28 0.1 12.1800 1.5 0.5037 1.3 0.91 0.1754 0.6 2629 29 2618 14 2610 10 101
A015 85939 245 132 0.43 0.0 12.1900 1.3 0.4858 1.1 0.88 0.1820 0.6 2552 24 2619 12 2671 10 96
A115 73937 117 66 0.59 0.1 12.3100 1.1 0.4927 0.7 0.62 0.1812 0.9 2582 15 2628 10 2664 14 97
A076 19676 32 19 0.85 b.d. 12.3500 1.4 0.4905 0.9 0.63 0.1826 1.1 2573 19 2631 14 2676 19 96
A008 82055 205 116 0.53 1.1 12.3600 1.2 0.4883 0.8 0.67 0.1835 0.9 2564 17 2632 11 2685 14 95
A057 51762 287 175 0.86 0.0 12.4100 1.3 0.5104 1.0 0.76 0.1764 0.9 2658 22 2636 12 2619 14 101
A088 133707 213 112 0.13 0.0 12.5000 1.0 0.5015 0.6 0.64 0.1808 0.8 2620 14 2643 9 2660 13 99
A066 39755 215 118 0.36 0.0 12.5400 1.1 0.5018 0.8 0.69 0.1812 0.8 2622 17 2646 11 2664 13 98
A038 58946 161 93 0.70 b.d. 12.5400 1.2 0.4959 0.9 0.74 0.1834 0.8 2596 19 2646 11 2684 14 97
A041 70978 390 225 0.54 0.0 12.5700 1.1 0.5080 0.9 0.81 0.1795 0.7 2648 20 2648 11 2648 11 100
A075 32892 111 70 1.13 0.0 12.5800 1.3 0.5099 0.9 0.66 0.1789 1.0 2656 19 2648 13 2643 17 101
A117 93943 288 173 0.91 0.1 12.6400 1.3 0.4997 0.9 0.69 0.1834 0.9 2613 19 2653 12 2684 15 97
A064 126213 340 213 1.19 0.0 12.7300 1.0 0.4968 0.8 0.80 0.1859 0.6 2600 17 2660 9 2706 10 96
A091 70903 109 65 0.65 0.3 12.9400 1.1 0.5112 0.7 0.67 0.1835 0.8 2662 16 2675 10 2685 13 99
A012 60316 152 89 0.50 0.1 13.2800 1.2 0.5175 0.9 0.78 0.1861 0.7 2688 20 2700 11 2708 12 99
A157 66320 97 58 0.89 0.1 13.3100 1.0 0.4913 0.6 0.62 0.1965 0.8 2577 13 2702 9 2797 12 92
A123 101485 131 81 0.65 0.1 16.0800 1.3 0.5199 1.0 0.75 0.2243 0.9 2699 22 2882 13 3012 14 90
A161 2789 84 7 0.55 0.7 0.5616 4.7 0.0761 1.0 0.22 0.0536 4.6 473 5 453 17 352 104 134
A079 13372 105 36 0.81 0.8 5.0220 1.8 0.2974 0.7 0.41 0.1225 1.6 1678 11 1823 15 1992 29 84
A090 19901 68 23 0.56 b.d.
5.4770 1.5 0.3094 0.8 0.55 0.1284 1.3 1738 13 1897 13 2076 23 84
A047 14757 83 30 0.63 0.1 5.5900 1.6 0.3225 0.8 0.47 0.1257 1.4 1802 12 1915 14 2039 25 88
A124 5979 23 9 1.24 0.0 5.7630 2.3 0.3107 1.1 0.47 0.1345 2.1 1744 17 1941 20 2158 36 81
A144 6490 20 8 0.91 b.d.
5.8590 1.9 0.3259 1.0 0.54 0.1304 1.6 1818 16 1955 17 2103 28 86
A130 53980 373 137 0.59 0.1 6.8090 1.1 0.3369 0.7 0.62 0.1466 0.9 1872 11 2087 10 2306 15 81
A107 176243 476 158 0.09 0.0 6.8570 1.2 0.3258 0.8 0.68 0.1527 0.9 1818 13 2093 11 2376 15 77
A089 70574 155 66 0.97 b.d.
7.8820 1.2 0.3736 0.9 0.74 0.1530 0.8 2046 16 2218 11 2380 14 86
265