Turning Exorheic – Capture and Fluvial Incision of Basins Under External Forcing (Ex-CaLIBUR)

Summary

Ex-CaLIBUR targets a key gap in Quaternary basin research: despite work on stream capture, the dynamics, timing, and external forcing of the endorheic-to-exorheic transition and ensuing drainage evolution remain poorly understood. The project applies a morphochronologic approach to the Guadix-Baza Basin (GBB, southern Spain), which preserves terminal endorheic glacis deposits and the oldest exorheic terraces but lacks systematic in situ terrestrial cosmogenic nuclide (TCN) dating. The project aims encompass:

• constraining the timing of basin capture by dating the upper glacis and oldest preserved fluvial terraces, narrowing current estimates (≈240–780 ka) and establishing a baseline to derive climate- and tectonically driven basin dissection,
• resolving how the local capture signal propagated across the structurally segmented GBB and its subbasins by combining TCN dating with morphometric analyses,
• and testing for diachronous terminal glacis aggradation from proximal to distal positions to distinguish progradational trends from headward capturing.

Results will yield first-order constraints on landscape transition dynamics in this Mediterranean natural laboratory, its external drivers, and provide transferable methods for basins worldwide.