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

DMS90-38B (Sanidine / 61A)

5095-01 0.0218 0.00031 2.4285 96.5 12.151 0.193

5095-02 0.0438 0.00086 2.3712 90.4 11.865 0.277

5095-03 0.0370 0.00072 2.4049 92.0 12.033 0.290

5095-04 0.0304 0.00021 2.4401 97.6 12.209 0.380

5095-05 0.0182 0.00249 2.4570 76.8 12.137 0.927

Weighted Mean = 12.07 ± 0.13 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