Denudation asymmetries and drainage divide migration: Insights into the evolution of the Devonian Escarpment in Paraná, Brazil

The evolution of passive margin escarpments is governed by the interplay of erosion, drainage divide migration, and landscape development. This study examines the Devonian Escarpment and Paranapiacaba Range in Paraná, Brazil, using geomorphic indices, morphometric analyses, and cosmogenic nuclides (¹⁰Be and ²⁶Al) to elucidate these processes. Maximum denudation rates range from 4.3 ± 0.4 to 18.3 ± 1.4 m Myr⁻¹, with the highest values in the Upper Ribeira Valley (weighted mean: 10.0 ± 0.3 m Myr⁻¹) and the lowest on the reverse side of the Escarpment Plateau (weighted mean: 5.8 ± 0.2 m Myr⁻¹). Apparent burial durations vary from 0.2 ± 0.1 to 1.5 ± 0.8 Myr, with significant Al-Be depletion (up to 69 %) observed across most watersheds, reflecting complex sediment exposure and storage histories. Divide migration rates are lower than 335 ± 58 m Myr⁻¹, indicating active basin reorganization driven by lithological, structural, and climatic controls. These findings provide a quantitative framework for understanding long-term landscape evolution and passive margin escarpment dynamics in tropical environments.