On the Complexity of River Terrace Formation: A High-Resolution Luminescence Chronology from the Fault-Controlled Guadix-Baza Basin (SE Spain)

River terraces are key archives of landscape evolution, shaped by the interplay of climatic, tectonic, and geomorphic processes. While often treated as regionally synchronous responses to glacial-interglacial cycles, growing evidence suggests that their formation can be far more complex and spatially variable. This study contributes to the broader understanding of terrace genesis by presenting new data from the Guadix-Baza Basin in southeastern Spain—a region marked by active faulting, significant elevation contrasts, and a long history of fluvial reorganization.

Initially a closed intramontane basin, Guadix-Baza evolved into an open drainage system during the Middle to Late Pleistocene due to river capture. This transition, combined with sustained neotectonic activity—especially along the Baza Fault system—led to the formation of multiple, spatially discontinuous terrace levels. Traditionally, terrace chronologies have relied on single-point dating approaches. In contrast, our study employs high-resolution luminescence dating across a wide range of sites to reconstruct the temporal structure of terrace development.

The results reveal a non-uniform fluvial response that cannot be attributed to simple climatic or tectonic forcing alone. Instead, terrace formation reflects a complex mosaic of local controls, including differential uplift, sediment supply, and basin morphology. Apparent chronological inconsistencies between sites can be reconciled within a stratigraphically and tectonically informed model of landscape evolution. Our findings underscore the necessity of integrating detailed field observations with robust geochronological frameworks to adequately capture the complexity of river terrace formation.