Stratigraphic variations in the Diaokou lobe area of the Yellow River delta, China: Implications for an evolutionary model of a delta lobe

Characterization of the evolution of delta lobes has theoretical significance for the formation of entire deltas. The Diaokou lobe of the Yellow River delta provides a typical example. The Yellow River transported a great deal of sediment to the Diaokou area during the period of 1964-76 after the river changed its course to the Diaokou River and formed a new delta lobe - the Diaokou lobe. The Diaokou lobe reflects the evolution of the modern Yellow River delta and contains a record that represents the complete modern Yellow River delta depositional system. Using grainsize characteristics, magnetism, and the accelerator mass spectrometry (AMS) 14C dating of cores ZK10-3 and ZK30 in the northern part of the Diaokou lobe, combined with collected data from cores ZK227, ZK1 and ZK228, which are located further south on the Diaokou lobe, we analysed the Holocene and recent stratigraphy of the Diaokou lobe area and its evolution. The Holocene stratigraphy of the Diaokou lobe and the nearby area contains upwards-succession, shallow-marine, river and lake, salt-marsh, and delta facies. This area received deltaic deposits beginning in 1855 and experienced prodelta, delta-front (lateral) and delta-plain deposition. When the Diaokou lobe began to form, this area experienced four stages of deposition after 1964: (1) dispersed-flow deposition; (2) single-channel deposition; (3) diversion deposition; and (4) abandonment and erosion. Compared with the evolution of a lobe of the Mississippi delta, the Yellow River delta contains thick, laterally extensive deposits as a result of the higher sediment load.