Correction factors used to account for interfering nuclear reactions for all samples except Core 180-1108B-6R feldspar and biotite (see below) are: (36Ar/37Ar)Ca = 0.000242 ± 0.000084, (38Ar/37Ar)Ca = 0.00193 ± 0.000042, (39Ar/37Ar)Ca = 0.0010709 ± 0.0001023, (40Ar/39Ar)K = 0.0199 ± 0.0087, (38Ar/39Ar)K = 0.012542 ± 0.000057. Correction factors used to account for interfering nuclear reactions for Core 180-1108B-6R feldspar and biotite are: (36Ar/37Ar)Ca = 0.00045 ± 0.00015, (38Ar/37Ar)Ca = 0.00042 ± 0.00014, (39Ar/37Ar)Ca = 0.00118 ± 0.0004, (40Ar/39Ar)K = 0.0416 ± 0.0054, (38Ar/39Ar)K = 0.0163 ± 0.0001.