Inversion of topographic evolution using low-T thermal history: A case study from coastal mountain system in Southeastern China

Abstract The topographic evolution of a mountain system provides key information for understanding surface processes. We present a new and relatively simple method to reconstruct two-dimensional paleotopography composed of two steps: (1) construction of thermal history using low-temperature thermochronological data and (2) conversion of the thermal history into topographic evolution. A new computer program “ Low-T Topo ” was developed to perform the suggested conversion of thermal history to paleotopography. This approach, when applied to the coastal mountain system (CMS) in Southeastern China, suggests an uneven topographic evolution along the Changting-Zhangzhou section since the Late Cretaceous. According to our modeling, the SE segment of the section was higher (maximum peak elevation = ~3.8 km) than the NW segment (~3.4 km) during ~80–50 Ma. The modeling also suggests that both the SE and NW segments experienced an initially higher exhumation rate of ~0.14 km/Myr at 80–70 Ma, which steadily decreased to about 0.03 km/Myr at 40 Ma. Since then, exhumation rates stayed relatively low (≤~0.05 km/Myr). The elevation reduction in the CMS since the Late Cretaceous played an important role introducing the warm and humid Pacific air to the inland.