Control mechanisms on deep-time gravel distribution: Insights from sediment generation and routing systems in the northwestern Kuqa Foreland Basin, Northwest China

The spatiotemporal distribution of gravel deposits in foreland basins integrates tectonic, climatic, and provenance controls, yet systematic cascade-control frameworks remain limited. Using an integrated approach that considers sediment generation and the sediment routing system, we established a three-tiered model to decipher the internal mechanisms controlling sediment production, transport, and pathway reorganization in the Neogene−Quaternary Kuqa Depression of Northwest China. This model links provenance attributes, tectonic-climate coupling, and basin response. Multidisciplinary, high-resolution datasets—including cores, thin sections, cuttings, well logs, and 3-D seismic volumes—were synthesized for analysis of provenance systems, sediment conduits, depositional architecture, and gravel compositional patterns. Development of a multifactor coupled depositional evolution model revealed that gravel distribution in early−late Miocene (Jidike to Kangcun formation) fan delta−lacustrine systems was controlled by catchment area and parent rock lithology, whereas Pliocene−Pleistocene (Kuche to Xiyu formations) alluvial fan−fluvial systems were dominated by drainage divide location, provenance distance, hydrodynamic regime, and source rock exposure area. The construction of a three-tiered model, which links provenance, tectonics, climate, and basin response, resulted in three main findings: (1) Provenance attributes govern gravel production via source rock lithology, spatial configuration, and sediment conduits, resulting in multisource gravel assemblages with variable productivity. Provenance evolution includes three phases: mixed northern-central-southern Tianshan, southern Tianshan dominance, and intrabasinal sourcing. (2) Tectonic-climatic interplay modulates sediment routing networks. Paleotopography and structural dynamics govern sediment dispersal pathways and spatial configurations through their controls on source terrain exhumation, subsidence history, and landscape reorganization. Climatic variability additionally influences sedimentary textural attributes and compositional zonation through its regulation of precipitation patterns, stream discharge regimes, and weathering processes. (3) Basin-level controls, including spatial differences among transport conduits and the dynamic evolution of accommodation space, govern gravel thickness and fan progradation direction, and ultimately dictate the resultant gravel distribution patterns. This study deepens understanding of provenance, tectonic, and climate interactions; clarifies sediment-generation routing linkages; and offers a predictive theoretical framework for sediment dispersal and depositional architecture evolution in orogenic belt−basin systems.