Figure 6: Plots of ln EA versus ln M from with serial deletions of abundance biozones during the accumulation procedure. Dashed lines indicate the positions at which abundance biozone (AB) boundaries are identified. (a) Grouping of the first 3 samples as ABA. (b) Following deletion of the first three samples, grouping of the next two as ABB. Figures 6(c) through 6(h) continue this sequential procedure until all samples are accounted for.