Alpine Regosols are vital for sustaining alpine desert steppe ecosystems in cold, arid, high-altitude regions. However, the parent material provenance, formation processes and vertical physicochemical gradients of these soils remain poorly understood along the Tibetan Plateau's cryospheric boundaries. This study focuses on Regosols and their potential parent materials (e.g., glacial debris, alluvial deposits) in an eastern Pamir alpine valley, aiming to elucidate provenance relationships and sediment cycling pathways between these soils and their source materials. We further characterize the formation of sand dunes along Baisha Lake via comprehensive physicochemical analyses. The results demonstrate: 1) A felsic-dominated provenance (Th/Sc > 3, Cr/Th < 2.5), showing minimal particle-size sorting effects, with sediment type being the primary factor controlling elemental concentration signatures across various sedimentary deposits. 2) Regosols are dominated by <125 mu m particles, maintaining consistent fine-fraction characteristics across elevation gradients. Geochemical indicators confirm their alluvial sediment origins, aligning with the physicochemical properties of alluvial deposits. Valley Fluvisols, however, contain localized coarse particles (>250 mu m), likely introduced via slope processes or episodic flooding and disrupting their otherwise homogeneous fine-grained composition. 3) Dune and river sand exhibit negligible <20 mu m fractions but significant Zr-Hf enrichment in the <63 mu m fraction; their corresponding physicochemical characteristics (e.g., grain-size distributions, Zr-Hf concentrations) indicate a proximal source relationship, demonstrating that Baisha Lake's aeolian dunes are principally derived from river sands. 4) We propose a developmental model for alpine Regosols, emphasizing the combined effects of cryo-aeolian processes and limited chemical weathering in the Tibetan Plateau's cold, arid, high-mountain valley environments.