Late Quaternary geomorphological processes and landscape evolution in the Kkoor va Biabanak basin using quartz OSL and K-feldspar pIRIR225 ages

The Central Iranian Plateau is a key region for understanding Late Quaternary landscape evolution. However, palaeoenvironmental reconstructions remain limited due to harsh climatic conditions and difficult access. The Khoor va Biabanak Basin, at the eastern edge of the Great Kavir, preserves diverse geomorphological archives that record interactions between climate and surface processes.

We used an integrative approach combining geomorphological mapping, stratigraphical analyses, and luminescence dating of 12 sedimentary sequences across eight geomorphic units, including pediments, alluvial fans, dunes, sand sheets, and playa surfaces.

Quartz OSL signals from dunes and sand sheets were generally dim and dominated by medium and slow components. Dose recovery tests show limited reliability, with high failure rates for recycling and recuperation, although performance improved at preheat temperatures of 180-280 °C. OSL-IR depletion tests indicate feldspar contamination in ~21% of aliquots, limiting the applicability of quartz OSL in this setting.

Preliminary K-feldspar pIRIR₂₂₅ results are more promising. Fading rates range from 0.5–2.3% per decade, and residual doses are 2–5%. The first age estimates are currently in progress and will provide essential chronological constraints for Late Quaternary geomorphological processes in the basin.

The oldest landforms indicate alternating pediment erosion, alluvial fan deposition, dune activity, and soil formation, likely corresponding to periods before and during MIS 3. Subsequent alluvial fan progradation and dune development reflect cold and arid conditions during the Last Glacial Maximum. Holocene features show increasing aridity, including gypsum-rich soils, dune reactivation, and deflation of playa surfaces. In the future, with the completion of dating results, these observations will allow a robust reconstruction of Late Quaternary landscape evolution and its climatic drivers in the Khoor Basin.

This study provides the first comprehensive model for landscape evolution in the Khoor va Biabanak Basin, demonstrating both the potential and limitations of luminescence dating in arid-region environments and highlighting the complex interactions between climate, geomorphology, and sedimentary processes in Central Iran.