Geochemical characterization of the middle and late Pleistocene alluvial fan-dominated infill of the northern part of the Weihe Basin, Central China

The lower (~ 1000-690 ka) and upper (~ 330-0 ka) units of the core are characterized by relative intense and frequent flooding, which coincided with extensive ponding in the study area. In the middle unit (~ 690-330 ka) increased salinity levels caused by evaporation, as reflected in the high Sr/Ca ratio and dolomite abundance, led to increased carbonate precipitation. Simultaneously, the increased influx of fine sediments indicates increased clay production in the source area as a result of a more intense summer monsoon strength after 600 ka.