Figure 6. Compilations of ages in four main time periods. Map background is crustal thickness average from synthesis work published in this monograph (Yang et al., this issue ). (a-d) Bedrock ages. (e-h) Detrital ages. (a)&(e) Modern configuration (30-0 Ma). (b)&(f) Pacific subduction configuration (50-30 Ma). (c)&(g) Slab window configuration, after Kula plate breakoff (60-50 Ma). (d)&(h) Kula subduction configuration (100-60 Ma). All labels as in Fig. 4.