287 / 352
271
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.
g
(cps) (ppm) (ppm)
U (%)
235
U (%)
238
U (%) (rho)
206
Pb (%)
238
U (Ma)
235
U (Ma)
206
Pb (Ma) (%)
Grain
A022 20804 93 43 1.19 0.4 6.6230 1.8 0.3771 1.4 0.77 0.1274 1.1 2063 24 2062 16 2062 20 100
A169 5689 27 13 1.38 1.8 6.6240 2.3 0.3713 1.7 0.72 0.1294 1.6 2036 29 2063 21 2090 28 97
A155 11987 65 27 0.69 0.1 6.6270 2.1 0.3748 1.4 0.68 0.1282 1.6 2052 25 2063 19 2074 27 99
A056 10348 47 22 1.22 0.2 6.6390 2.1 0.3734 1.4 0.68 0.1289 1.6 2045 25 2065 19 2084 28 98
A153 28418 152 61 0.54 0.0 6.6410 1.6 0.3725 1.3 0.79 0.1293 1.0 2041 22 2065 14 2088 17 98
A098 11409 56 24 0.86 b.d.
6.6540 1.8 0.3788 1.3 0.74 0.1274 1.2 2071 24 2067 16 2063 22 100
A177 28307 114 53 0.70 6.0 6.6730 3.7 0.3776 1.4 0.39 0.1282 3.4 2065 26 2069 33 2073 60 100
A200 14293 165 76 1.24 0.0 6.6780 1.9 0.3745 1.4 0.76 0.1293 1.2 2050 25 2070 17 2089 21 98
A159 25231 144 68 1.37 b.d.
6.7040 1.7 0.3770 1.4 0.79 0.1290 1.1 2062 24 2073 15 2084 19 99
A021 4543 20 8 0.59 b.d.
6.8290 2.4 0.3823 1.5 0.61 0.1295 1.9 2087 26 2089 22 2092 34 100
A040 5521 24 11 0.92 0.2 6.8650 2.2 0.3867 1.5 0.66 0.1287 1.7 2108 26 2094 20 2081 29 101
A190 17178 93 40 0.61 1.2 6.8810 2.9 0.3829 2.3 0.79 0.1303 1.8 2090 40 2096 26 2102 31 99
A125 8804 44 19 0.75 0.1 6.8950 2.0 0.3844 1.7 0.83 0.1301 1.1 2097 30 2098 18 2099 19 100
A191 46244 255 126 1.65 b.d.
6.9200 1.5 0.3797 1.3 0.87 0.1322 0.7 2075 23 2101 13 2127 13 98
A145 10686 53 23 0.75 0.0 6.9260 1.8 0.3863 1.3 0.70 0.1300 1.3 2106 23 2102 16 2099 23 100
A115 16167 75 32 0.65 0.0 6.9410 1.7 0.3816 1.3 0.78 0.1319 1.1 2084 24 2104 15 2124 19 98
A162 28522 148 63 0.86 0.0 7
.0090 1.7 0.3661 1.3
0.78 0.1389 1.0 2011 23 2113 15 2213 18 91
A174 8530 42 20 1.44 b.d.
7.2550 2.1 0.3916 1.5 0.71 0.1344 1.5 2130 27 2143 19 2156 25 99
A092 5529 23 11 1.10 0.0 7.8300 1.8 0.3924 1.5 0.81 0.1447 1.1 2134 27 2212 17 2285 18 93
A121 40361 329 132 0.15 0.1 8.0460 1.9 0.3882 1.6 0.84 0.1503 1.0 2115 28 2236 17 2349 17 90
A138 12294 49 22 0.59 0.1 8.2770 1.8 0.3996 1.4 0.74 0.1502 1.2 2167 25 2262 17 2349 21 92
A054 36795 263 106 0.11 0.0 8.4310 1.8 0.3956 1.5 0.81 0.1546 1.1 2149 27 2279 17 2397 18 90
A088 58872 494 205 0.18 0.0 8.4790 1.6 0.4024 1.4 0.84 0.1528 0.9 2180 25 2284 15 2378 15 92
A062 74976 545 238 0.22 0.0 8.5610 1.6 0.4213 1.4 0.87 0.1474 0.8 2267 26 2292 14 2316 14 98
A028 222483 1512 656 0.08 0.0 9.2280 1.4 0.4257 1.3 0.91 0.1572 0.6 2286 24 2361 13 2426 10 94
A023 53933 165 81 0.71 b.d.
9.7640 1.6 0.4296 1.4 0.87 0.1648 0.8 2304 27 2413 15 2506 13 92
A053 27403 187 90 0.62 0.1 9.8110 2.2 0.4280 1.9 0.87 0.1663 1.1 2297 37 2417 21 2520 19 91
A074 60279 379 211 1.02 0.1 10.4500 1.7 0.4640 1.5 0.86 0.1634 0.9 2457 30 2476 16 2491 15 99
A142 31496 103 51 0.56 0.0 10.5400 1.8 0.4368 1.5 0.85 0.1749 0.9 2336 29 2483 16 2605 16 90
A030 103946 587 280 0.15 0.0 10.5900 1.9 0.4597 1.8 0.94 0.1671 0.7 2438 36 2488 18 2528 11 96
A077 15338 46 22 0.13 b.d. 10.6200 1.8 0.4624 1.4 0.77 0.1665 1.2 2450 28 2490 17 2523 19 97
A060 27281 158 81 0.48 0.1 10.6400 1.8 0.4634 1.5 0.86 0.1666 0.9 2455 32 2493 17 2524 15 97
A118 54993 336 167 0.51 0.0 10.7100 1.9 0.4442 1.5 0.83 0.1749 1.0 2369 31 2499 17 2605 17 91
A052 29790 184 95 0.58 0.1 10.7900 2.1 0.4629 1.8 0.85 0.1691 1.1 2452 37 2505 20 2548 18 96
A189 81741 337 184 0.92 0.0 11.1000 2.1 0.4596 1.5 0.71 0.1752 1.4 2438 30 2532 19 2608 24 93
A025 50455 262 129 0.22 0.1 11.1100 1.7 0.4633 1.5 0.90 0.1740 0.7 2454 31 2533 16 2596 12 95
A094 50737 284 145 0.25 0.0 11.2400 1.7 0.4835 1.4 0.83 0.1685 1.0 2542 30 2543 16 2543 16 100
A076 25894 145 79 0.71 0.0 11.2800 1.7 0.4706 1.3 0.76 0.1738 1.1 2486 27 2546 16 2595 19 96
A109 32539 40 23 1.01 b.d. 11.3900 1.6 0.4706 1.3 0.84 0.1755 0.9 2486 28 2555 15 2611 15 95
A141 12558 40 23 1.12 0.0 11.5500 2.0 0.4745 1.4 0.70 0.1766 1.5 2503 30 2569 19 2621 24 96
A117 80390 583 308 0.51 0.0 11.5900 1.9 0.4852 1.6 0.84 0.1733 1.0 2550 34 2572 18 2590 17 98
A091 30295 80 41 0.27 0.0 11.6000 1.7 0.4814 1.3 0.78 0.1748 1.1 2533 28 2573 16 2605 18 97
A201 32237 205 128 1.47 0.1 11.6100 1.8 0.4722 1.5 0.83 0.1783 1.0 2493 30 2573 17 2637 16 95
A151 8431 25 14 0.98 0.0 11.6700 1.9 0.4662 1.5 0.76 0.1816 1.3 2467 30 2578 18 2667 21 92
A058 58559 145 76 0.33 0.8 11.6800 2.2 0.4772 1.9 0.84 0.1775 1.2 2515 39 2579 21 2630 20 96
A179 25381 161 88 0.63 0.0 11.7000 1.7 0.4862 1.3 0.77 0.1744 1.1 2554 28 2580 16 2601 18 98
A156 47116 269 168 1.34 0.0 11.7700 1.9 0.4898 1.7 0.89 0.1743 0.9 2570 36 2586 18 2599 14 99
A050 25462 62 35 0.75 0.3 11.7700 1.8 0.4843 1.5 0.81 0.1763 1.1 2546 31 2587 17 2619 18 97
A111 43137 125 73 1.06 b.d. 11.8400 1.5 0.4819 1.3 0.86 0.1782 0.8 2535 28 2592 14 2636 13 96
A170 56342 188 113 1.02 b.d. 11.9800 1.5 0.4965 1.3 0.86 0.1750 0.8 2599 28 2603 15 2606 13 100
A059 70515 190 113 0.79 b.d. 12.1100 1.8 0.5010 1.5 0.83 0.1753 1.0 2618 32 2613 17 2609 17 100
A089 25810 68 42 1.27 0.0 12.1100 1.7 0.4980 1.4 0.82 0.1764 0.9 2605 30 2613 16 2619 16 99
A072 57764 151 96 1.41 0.0 12.2000 1.5 0.4940 1.3 0.91 0.1791 0.6 2588 29 2620 14 2644 10 98
A158 69833 205 115 0.69 0.1 12.2100 1.7 0.4843 1.4 0.82 0.1829 1.0 2546 29 2621 16 2679 16 95
A097 82517 416 252 0.98 0.1 12.2800 1.5 0.4975 1.4 0.90 0.1791 0.7 2603 29 2626 14 2644 11 98
A045 98036 234 142 1.13 b.d. 12.3800 1.5 0.4886 1.3 0.88 0.1838 0.7 2565 28 2634 14 2688 12 95
A107 31355 76 44 0.69 0.0 12.4100 1.6 0.4908 1.4 0.83 0.1833 0.9 2574 29 2636 15 2683 15 96
A039 40524 93 60 1.31 0.1 12.5600 1.7 0.5032 1.4 0.81 0.1811 1.0 2627 30 2648 16 2663 16 99
A026 47490 122 73 0.80 0.1 12.7500 1.6 0.5080 1.4 0.88 0.1821 0.8 2648 30 2661 15 2672 13 99
A044 53410 55 33 0.91 0.2 12.7800 1.6 0.5112 1.3 0.79 0.1813 1.0 2662 27 2663 15 2665 16 100
A082 113495 285 163 0.58 b.d. 12.9300 1.4 0.5044 1.3 0.89 0.1859 0.7 2633 28 2674 14 2706 11 97
A133 44088 225 148 1.37 0.2 12.9500 1.5 0.5076 1.4 0.89 0.1851 0.7 2646 30 2676 14 2699 11 98
A163 31503 166 107 1.17 0.0 12.9700 1.8 0.5140 1.5 0.81 0.1830 1.1 2674 32 2677 17 2680 18 100
A139 33022 93 53 0.59 0.0 12.9700 1.6 0.5098 1.4 0.83 0.1846 0.9 2656 30 2678 15 2694 15 99
A136 42620 224 128 0.48 0.0 13.0800 1.5 0.5097 1.4 0.91 0.1862 0.6 2655 30 2686 14 2709 10 98
A038 53374 121 105 3.29 b.d. 13.2100 1.7 0.5165 1.5 0.89 0.1854 0.8 2684 33 2694 16 2702 13 99
A168 39906 109 67 0.86 b.d. 13.2100 1.8 0.5199 1.6 0.85 0.1843 1.0 2699 34 2695 18 2692 16 100
A066 28640 44 32 0.90 5.1 13.3900 3.0 0.5181 1.7 0.58 0.1874 2.4 2691 38 2707 28 2720 40 99
A087 13070 31 21 1.59 0.1 13.4400 2.2 0.5223 1.6 0.74 0.1866 1.5 2709 36 2711 21 2713 24 100
A114 94668 357 220 0.71 0.1 13.9900 4.9 0.5176 4.8 0.98 0.1960 1.0 2689 106 2749 48 2793 17 96
271