The formation and sedimentary evolution of the Hutuohe River and its piedmont alluvial fan in the North China Plain

The Hutuohe River alluvial fan (HRAF) is the largest piedmont alluvial-pluvial fan in the North China Plain (NCP). The origin and sedimentary evolution of the Hutuohe River (HR) and the HRAF have long been debated. Through a comprehensive analysis of lithostratigraphy, lithofacies paleogeography, geochronology, and sedimentology of core JSZ01 in the HRAF (fan-middle), the final time of the HR formation is estimated to be no later than 2.116 Ma (the early Quaternary). The formation and sedimentary evolution of the HRAF can be divided into five stages, and its major development occurred between 2.116 and 0.103 Ma. The crucial controlling factor of the HRAF’s formation and sedimentary evolution is tectonic activity, followed by base-level change.