Sample %³⁹Ar ³⁷Ar/³⁹Ar ³⁶Ar/³⁹Ar ⁴⁰Ar^*/³⁹Ar %⁴⁰Ar^* Age (Ma) SD

DMS90-124B (Sanidine / 61B)

5099-01 0.0490 0.00151 3.0117 87.2 15.057 0.652

5099-02 0.0344 0.00003 2.9972 99.8 14.985 0.851

5099-03 0.0291 0.00021 2.9350 98.0 14.675 0.380

5099-04 0.0304 0.00002 3.0147 99.8 15.073 0.740

Weighted Mean = 14.84 ± 0.28 SE

DMS90-124B (Glass / 61B)

5098-01A 1.8 0.0478 0.00720 3.5246 62.4 17.609 2.047

5098-01B 43.9 0.0738 0.00422 3.0609 71.1 15.302 0.113

5098-01C 49.8 0.0923 0.00046 3.0407 95.9 15.202 0.082

5098-01D 2.2 0.0516 0.00143 2.9147 87.4 14.574 3.043

5098-01E 0.1 0.0000 0.00391 1.2365 51.7 6.197 50.949

5098-01F 2.1 0.0150 -0.00282 3.9130 127.1 19.539 1.655

Plateau Age = 15.24 ± 0.08 SE

Irradiation Data

41B J = 0.005920 ± 0.0000090

61A J = 0.002847 ± 0.0000036

61B J = 0.002783 ± 0.0000024

98A J = 0.000478 ± 0.0000006