Taiwan's mountain building and landscape evolution: A cosmogenic perspective

Taiwan is a young arc-continent collisional orogen characterised by rapid exhumation, high relief, and a fluvial and landslide-dominated landscape. The obliquity between the convergence direction and the plate boundary trend creates gradients of uplift and variations in orogenic activity, with an immature orogen in the south, a mature orogen in the central and northern regions, and possible cessation of orogeny in the far north. Channel steepness strongly correlates with erosion rates, suggesting fluvial erosion as the dominant exhumation process, primarily driven by tectonic forcing. These processes maintain a quasi-equilibrium where erosion and uplift rates are nearly equal, shaping Taiwan’s dynamic and rapidly evolving landscape. Over the past two decades, in-situ produced cosmogenic nuclides, particularly ¹⁰Be in quartz-bearing rocks, have emerged as essential tools for studying bedrock erosion rates and landscape evolution. Early studies in Taiwan utilised atmospheric ¹⁰Be to measure sedimentation rates along continental margins, while later works employed in-situ ¹⁰Be to date glacial features, stream terraces, and soils, providing critical insights into surface deformation and climate. Applications of ¹⁰Be in modern river sediments revealed its capacity to address orogen-scale surface processes, with studies linking denudation rates to tectonic control in mature orogens. Recent research has refined these approaches, highlighting the effects of landslide sediment on ¹⁰Be concentrations and providing detailed spatial erosion patterns at the catchment scale. Building on this foundation, our presentation introduces a comprehensive dataset of unpublished spatial and temporal analyses, offering new perspectives on Taiwan’s topographic evolution. These data enhance our understanding of the interplay between surface processes and the construction of the central mountain range, enriching the broader narrative of Taiwan’s geomorphic evolution and the complexities of erosional processes driven by tectonics.