Table T3. 40Ar-39Ar data on multi-grain fractions.

Laser
power (W)
36Ar(atm)
37Ar(Ca)
38Ar(Cl)
39Ar(K)
40Ar(Total)
Age
(Ma)
±2
40Ar*%
39Ar(K)%
Ca/K
Cl/K
178-1097A-27R-1, 35-58 (10 grains) J = 0.0006101          
0.30 0.01374 0.01450 0.000439 0.03466 8.5112 136.0 2.5 52.3 43.0 0.789 0.00867
2.50 0.00133 0.03723 0.000143 0.02990 3.3837 106.9 3.3 88.4 37.1 2.350 0.00328
Fuse 0.00051 0.04146 0.000163 0.01609 1.6506 99.7 5.7 90.8 19.9 4.86 0.00692
Total fusion (1)         118.1 2.2     2.18 0.00632
0.30 0.01404 0.00830 0.000314 0.03309 8.4940 139.0 5.5 51.2 56.9 0.473 0.00650
2.50 0.00119 0.03091 0.000052 0.01802 2.0829 102.8 3.2 83.1 31.0 3.24 0.00196
Fuse 0.00042 0.03406 0.000071 0.00709 0.6157 74.9 8.7 80.0 12.2 9.06 0.00688
Total fusion (2)         120.1 3.5     2.38 0.00051
0.30 0.02017 0.01207 — 0.03612 11.519 161.9 5.7 48.2 29.6 0.631 —
2.50 0.00180 0.05099 0.000067 0.07003 7.2389 102.4 1.1 92.6 57.4 1.37 0.00066
Fuse 0.00046 0.05466 0.000038 0.01578 1.5827 98.2 4.2 91.4 12.9 6.54 0.00165
Total fusion (3)         119.7 2.0     1.82 0.00059
0.30 0.02409 0.02868 0.000092 0.02794 11.149 152.1 4.8 36.1 45.2 1.94 0.00225
2.50 0.00183 0.02217 0.000069 0.02346 3.0580 114.4 3.5 82.3 38.0 1.78 0.00202
Fuse 0.00054 0.05684 0.000241 0.01038 1.0980 97.0 4.8 85.6 16.8 10.3 0.01591
Total fusion (4)         128.7 2.7     3.29 0.00446
0.30 0.02450 0.01838 0.000358 0.05449 13.852 128.9 5.0 47.7 35.1 0.636 0.00449
2.50 0.00307 0.07396 0.000060 0.07290 10.531 139.7 1.9 91.4 47.0 1.91 0.00057
Fuse 0.00172 0.06871 0.000382 0.02773 5.0944 173.4 4.5 90.0 17.9 4.68 0.00944
Total fusion (5)         142.0 2.3     1.96 0.00353
178-1103A-36R-3, 4-8 (30 grains) J = 0.0006055      
0.30 0.02190 0.17832 0.01513 0.1689 9.0580 16.65 0.77 28.6 41.5 1.99 0.0614
2.50 0.01486 0.36118 0.01043 0.1671 6.4099 13.2 1.1 31.5 41.0 4.08 0.0427
Fuse 0.00630 0.27847 0.00486 0.07110 3.3325 22.5 1.2 44.1 17.5 7.39 0.0468
Total fusion (1)         16.23 0.59     3.79 0.0512
0.30 0.02043 0.15718 0.01710 0.2049 8.8648 15.02 0.91 31.9 42.1 1.45 0.0572
2.50 0.00616 0.32642 0.01194 0.2089 6.1354 22.43 0.47 70.3 42.9 2.95 0.0391
Fuse 0.00306 0.18759 0.00398 0.07323 2.4822 23.4 1.1 63.5 15.0 4.83 0.0373
Total fusion (2)         19.46 0.48     2.60 0.0465
0.30 0.04537 0.12835 0.01421 0.1702 15.534 13.6 2.9 13.7 38.5 1.42 0.0572
2.50 0.00773 0.18650 0.02103 0.2715 4.8246 10.19 0.31 52.6 61.5 1.30 0.0531
Total fusion (3)**         11.5 1.1     1.35 0.0547
0.30 0.01987 0.06365 0.00609 0.08790 9.0946 39.6 2.8 35.4 20.8 1.37 0.0475
2.50 0.00767 0.31486 0.01122 0.2565 13.4346 46.95 0.36 83.1 60.8 2.32 0.0300
Fuse 0.00997 0.19887 0.00379 0.07734 5.7798 39.60 0.97 49.0 18.3 4.85 0.0336
Total fusion (4)         44.07 0.71     2.58 0.0343
0.30 0.01496 0.17008 0.01488 0.16764 6.2791 12.07 1.06 29.6 61.6 1.91 0.0608
2.50 0.00514 0.15854 0.00548 0.06959 2.0038 7.58 0.71 24.1 25.6 4.30 0.0540
Fuse 0.00180 0.14358 0.00254 0.03503 0.8175 8.9 1.8 34.8 12.9 7.73 0.0497
Total fusion (5)         10.51 0.72     3.27 0.0576
0.20 0.00184 0.02750 0.00334 0.03966 1.0643 14.3 2.1 48.9 9.1 1.31 0.0578
2.50 0.01212 0.38295 0.01959 0.3174 8.7263 17.62 0.66 58.9 72.4 2.28 0.0423
Fuse 0.00261 0.15455 0.00351 0.08111 2.6734 25.4 1.3 71.1 18.5 3.60 0.0297
Total fusion (6)         18.77 0.58     2.43 0.0413
0.30 0.00381 0.08094 0.00876 0.12325 3.2553 18.77 0.79 65.4 36.9 1.24 0.0487
2.50 0.00789 0.27852 0.00915 0.17038 4.7174 15.23 0.84 50.6 51.0 3.08 0.0368
Fuse 0.00114 0.06187 0.00199 0.04021 0.8526 14.0 1.1 60.5 12.0 2.90 0.0340
Total fusion (7)         16.39 0.54     2.38 0.0408
0.30 0.00784 0.10476 0.00931 0.13349 3.9554 13.4 1.1 41.4 42.3 1.48 0.0478
2.50 0.00434 0.16440 0.00804 0.12308 3.1241 16.3 1.8 59.0 39.0 2.52 0.0447
Fuse 0.00392 0.12439 0.00302 0.05883 1.7934 11.8 2.7 35.4 18.7 3.99 0.0351
Total fusion (8)         14.20 0.97     2.35 0.0442
0.30 0.01589 0.10916 0.00947 0.1407 7.7633 23.7 1.1 39.5 40.6 1.46 0.0461
2.50 0.00805 0.19166 0.00822 0.1372 4.9662 20.48 0.68 52.1 39.6 2.64 0.0410
Fuse 0.00271 0.08859 0.00242 0.06851 3.9967 50.2 1.4 79.9 19.8 2.44 0.0242
Total fusion (9)         27.69 0.59     2.12 0.0398
178-1103A-31R-2, 0-4 cm (30 grains) J = 0.0006015        
0.80 0.05528 0.18844 0.01771 0.2999 21.902 20.03 0.70 25.4 79.2 1.19 0.0404
1.80 0.01147 0.07760 0.00227 0.05063 4.3841 21.2 5.2 22.7 13.4 2.89 0.0307
Fuse 0.00322 0.04598 0.00116 0.02791 2.0102 40.7 2.0 52.7 7.4 3.11 0.0284
Total fusion (1)         21.72 0.91     1.56 0.0383
0.90 0.06668 0.37257 0.02675 0.3651 25.650 17.59 0.68 23.2 67.6 1.93 0.0502
2.40 0.00835 0.12221 0.00520 0.08370 4.2266 22.65 0.80 41.6 15.5 2.76 0.0426
Fuse 0.01026 0.20752 0.00478 0.09120 5.5567 29.8 2.0 45.4 16.9 4.29 0.0359
Total fusion (2)         20.44 0.60     2.45 0.0466
0.40 0.03091 0.11609 0.01054 0.1747 12.691 22.0 1.7 28.0 47.1 1.25 0.0413
2.50 0.01274 0.17526 0.00608 0.1562 6.3921 18.16 0.81 41.1 42.1 2.12 0.0267
Fuse 0.00470 0.06368 0.00210 0.04029 2.2810 23.9 3.1 39.1 10.9 2.98 0.0357
Total fusion (3)         20.58 0.92     1.80 0.0345
0.40 0.05939 0.13952 0.00993 0.1998 24.144 35.47 0.78 27.3 65.9 1.32 0.0340
2.50 0.00478 0.10570 0.00275 0.07833 4.0605 36.3 1.4 65.2 25.8 2.55 0.0240
Fuse 0.00246 0.04932 0.00076 0.02521 1.9288 51.0 5.3 62.3 8.3 3.69 0.0206
Total fusion (4)         36.98 0.80     1.83 0.0303
0.30 0.04550 0.12811 0.01406 0.2473 21.474 34.89 0.86 37.4 41.4 0.98 0.0389
2.50 0.02261 0.26826 0.01300 0.2623 15.501 36.12 0.69 56.9 43.9 1.93 0.0339
Fuse 0.00750 0.11478 0.00321 0.08825 6.9419 57.2 1.4 68.1 14.8 2.45 0.0249
Total fusion (5)         38.74 0.56     1.61 0.0347
0.30 0.02806 0.10043 0.01123 0.1591 11.676 22.9 1.2 29.0 37.3 1.19 0.0483
2.50 0.01684 0.22645 0.00888 0.1960 10.997 33.02 0.47 54.7 46.0 2.18 0.0310
Fuse 0.00551 0.10905 0.00288 0.07129 4.4072 41.8 1.1 63.0 16.7 2.89 0.0277
Total fusion (6)         30.73 0.56     1.93 0.0369
0.30 0.00820 0.05156 0.00727 0.1091 4.5880 21.4 1.1 47.2 28.1 0.891 0.0456
2.50 0.00956 0.21198 0.00940 0.2039 7.5544 24.99 0.76 62.6 52.5 1.96 0.0316
Fuse 0.00388 0.11014 0.00291 0.07534 3.3410 31.3 1.3 65.7 19.4 2.76 0.0265
Total fusion (7)         25.22 0.59     1.82 0.0345
0.30 0.00704 0.07496 0.00578 0.1071 5.2186 31.51 0.80 60.1 39.9 1.32 0.0370
2.50 0.00479 0.17473 0.00591 0.1343 6.2567 38.68 0.89 77.3 50.1 2.45 0.0302
Fuse 0.00148 0.04707 0.00109 0.02677 1.4380 40.1 3.9 69.5 10.0 3.32 0.0280
Total fusion (8)         35.96 0.71     2.09 0.0327
0.30 0.00690 0.08108 0.00761 0.1164 4.2148 20.2 1.3 51.6 45.4 1.31 0.0448
2.50 0.00745 0.14725 0.00604 0.1150 4.4063 20.7 1.3 50.0 44.8 2.42 0.0360
Fuse 0.00181 0.03534 0.00152 0.02524 1.3063 32.9 4.8 59.1 9.8 2.64 0.0414
Total fusion (9)         21.65 0.94     1.94 0.0405
0.30 0.00567 0.09547 0.00780 0.1307 3.8572 18.0 1.2 56.5 45.8 1.38 0.0409
2.50 0.00581 0.15897 0.00508 0.1148 4.3240 24.48 0.91 60.3 40.2 2.61 0.0303
Fuse 0.00200 0.04540 0.00135 0.03992 1.9852 37.5 2.4 70.3 14.0 2.15 0.0231
Total fusion (10)         23.35 0.76     1.98 0.0342
0.30 0.00390 0.04440 0.00399 0.07704 2.9107 24.6 1.9 60.4 33.6 1.09 0.0354
2.50 0.00939 0.16839 0.00617 0.1287 6.3955 30.3 1.3 56.6 56.1 2.47 0.0329
Fuse 0.00119 0.03267 0.00088 0.02378 1.1781 37.4 2.4 70.2 10.4 2.59 0.0252
Total fusion (11)         29.1 1.0     2.02 0.0329

Notes: ** = the final step was lost for a technical reason. Argon data are x 10-15 moles. — = undetectable.