Sample % 39Ar 37Ar/39Ar 36Ar/39Ar 40Ar*/39Ar % 40*Ar Age (Ma) SD
DMS-8686B (61A2)
5705-01 0.0302 0.00023 0.8177 92.4 4.191 0.203
5075-02 0.0381 0.00020 0.8257 93.3 4.232 0.237
5705-03 0.0485 0.00001 0.8672 99.7 4.444 0.250
5705-04 0.0189 0.00032 0.8201 89.4 4.203 0.239
5705-05 0.0266 0.00052 0.8277 84.3 4.242 0.278
5705-06 0.0305 0.00019 0.8824 94.1 4.522 0.554
5075-07 0.0259 0.00005 0.8697 98.2 4.457 0.422
5705-08 0.0200 0.00015 0.8524 94.9 4.368 0.283
5705-09 0.0335 0.00027 0.8278 91.1 4.242 0.418
5705-10 0.0370 0.00031 0.8320 90.0 4.264 0.528
5705-11 0.0388 0.00013 0.8648 96.0 4.432 0.271
5705-12 0.0349 0.00023 0.8406 92.5 4.308 0.293
5705-13 0.0407 0.00018 0.8540 94.1 4.377 0.334
5705-14 0.0214 0.00021 0.8272 93.1 4.239 0.495
5705-15 0.0444 0.00003 0.8844 99.3 4.532 0.366
5705-16 0.0314 0.00009 0.8578 97.0 4.396 0.169
5705-17 0.0307 0.00008 0.8538 97.2 4.375 0.359
5705-18 0.0118 0.00025 0.8482 91.9 4.347 0.409
Weighted Mean = 4.33 +/- 0.07 SE
Irradiation Data
20 J=0.001428 +/- 0.000001
41B J=0.005920 +/- 0.000009
61B J=0.002783 +/- 0.000002
61A2 J=0.002844 +/- 0.000004
98A J=0.000478 +/- 0.000001