Combining landscape evolution and thermo-kinematic modeling to investigate the post-rifting evolution of the Great Escarpment, SE Australia

The Great Escarpment of SE Australia is a major geomorphic feature that separates a low-relief, high-elevation plateau from a near-sea-level coastal plain. Understanding the long-term evolution of this transition has been a long-standing challenge in geoscience. In particular, it remains unclear whether the escarpment reached its current position far from the rifted margin through continuous retreat at a relatively constant rate, or whether rapid retreat occurred shortly after rifting followed by stagnation, potentially linked to pre-existing structures. 

Recent developments in low-temperature thermochronology and modeling techniques provide new opportunities to address this question. Here, we integrate landscape evolution with thermo-kinematic modeling to evaluate thermochronology data, including apatite fission track, apatite (U-Th-Sm)/He, and newly acquired 4He/3He data. The coupled modeling approach directly links surface processes and drainage evolution to subsurface thermal histories, allowing for a more robust and physically consistent interpretation of thermochronological constraints on escarpment dynamics. This enables us to place quantitative constraints on the spatial and temporal scales of escarpment retreat and associated exhumation. Ultimately, we aim to assess whether the topographic evolution of the Great Escarpment is better explained by (1) a plateau degradation scenario, in which a pre-existing drainage divide facilitates rapid degradation of the coastal plain to its current position, or (2) an escarpment retreat scenario characterized by continuous inland erosional migration.