Figure 2

Modelled maximum salinity and velocity magnitude and inferred resulting morphological zonation. (a) 3D depth-averaged maximum salinity reached from a best-estimate Holocene highstand scenario (S_midWL₂D_avB_mod) demonstrates that the Lower Lakes were subject to significant marine incursion driving the brackish limit beyond Murray Bridge (rkm 118). The flood-tide delta is the only region where maximum velocity magnitudes exceed the limit for deposition of a laminated sequence over significant areas^24,25,26. (b) The reduction of sea level in the late Holocene (modelled as scenario S_midWL₀D_avB_mod) causes a significant change in the palaeo-environmental character of the region restricting the brackish limit to Wellington (rkm 85) and supressing marine incursion to the flood tide delta. Salinity categorisation is based on the classification scheme of Tooley⁶⁴.