Fig. 4

⁴⁰Ar/³⁹Ar ages of plagioclase-rich lithic fragments. ⁴⁰Ar/³⁹Ar ages of individual plagioclase-rich lithic fragments. The filled symbols represents the ⁴⁰Ar/³⁹Ar ages calculated after correcting measured ⁴⁰Ar for non-radiogenic trapped component using (⁴⁰Ar/³⁶Ar)_t = 0.146 (i.e., the y-intercept, Fig. 3). The open symbols represents ⁴⁰Ar/³⁹Ar ages calculated without any correction in measured ⁴⁰Ar for trapped contribution (e.g., Norman et al. 2006; Fernandes et al. 2013). The horizontal line represents the age of 4.13 ± 0.09 Ga, determined using the slope obtained in Fig. 3. The uncertainty shown for ⁴⁰Ar/³⁹Ar ages are 1σ