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

DMS89-211B (Sanidine / 41B)

3184-03 0.0146 0.00056 1.3377 89.0 14.231 0.109

3184-02 0.0137 0.00068 1.3567 87.0 14.432 0.105

3184-04 0.0131 0.00049 1.3967 90.5 14.856 0.091

Weighted Mean = 14.55 ± 0.06 SE

3184-01 0.0192 0.00125 2.1253 85.2 22.557 0.120

3184-05 0.0274 0.00085 12.4483 98.0 128.279 0.373

DMS89-211B (Glass / 41B)

3176-01 0.0824 0.00006 1.4128 99.1 15.026 0.043

3176-02 0.0827 0.00006 1.4168 99.1 15.068 0.045

3176-03 0.0837 0.00008 1.4246 98.7 15.151 0.050

Weighted Mean = 15.08 ± 0.03 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