Figure F3. A. 40Ar/39Ar age spectrum and (39Ar)K/(37Ar)Ca plot for Core 180-1109D-45R. White apparent age spectrum assumes an atmospheric (40Ar/36Ar)i = 295.5, the black spectrum is corrected using (40Ar/36Ar)i = 323.8 ± 7.7 from the isochron plot. B. Isochron plot for plagioclase Core 180-1109D-45R. MSWD = mean squared weighted deviates.

Figure F3. A. ⁴⁰Ar/³⁹Ar age spectrum and (³⁹Ar)_K/(³⁷Ar)_Ca plot for Core 180-1109D-45R. White apparent age spectrum assumes an atmospheric (⁴⁰Ar/³⁶Ar)_i= 295.5, the black spectrum is corrected using (⁴⁰Ar/³⁶Ar)_i = 323.8 ± 7.7 from the isochron plot. B. Isochron plot for plagioclase Core 180-1109D-45R. MSWD = mean squared weighted deviates.