Stratigraphic and three-dimensional morphological evolution of the late Quaternary sequences in the western Bohai Sea, China: Controls related to eustasy, high sediment supplies and neotectonics

Pollen and spore records constrained by millennial prodelta evolution: a case study of the Huanghe (Yellow River) delta

“…The seismic stratigraphy in the western and northwestern Bohai Sea has been extensively examined recently (Tian et al, 2017;Liu et al, 2019;2022), providing a critical foundation for this research (Figure 2). Postglacial stratigraphy in these regions comprises three sets of stratigraphic units (Liu et al, 2020): (1) terrestrial sediments formed during Late Pleistocene when the study area was subaerially exposed and devoid of seawater influence, primarily representing the Lowstand Systems Tract; (2) transgressive lags formed during the transgression through winnowing processes, especially wave action and ocean currents, often exhibiting as sand sheets and corresponding to the Transgressive Systems Tract; and (3) a unit of prodelta sediments formed since the mid-Holocene due to the progradation of neighboring river deltas, representing the Highstand Systems Tract (HST). These units are bounded by a transgressive (wave) ravinement surface (wRs) and a Maximum Flooding Surface (MFS).…”

“…To address this issue, we focus on the Huanghe delta, particularly its prodelta in the western and northwestern Bohai Sea, in this study, which, renowned as one of the largest deltas on Earth, has been extensively studied for its sedimentary and stratigraphic evolution in recent years (He et al, 2019;Liu et al, 2019Liu et al, , 2020Liu et al, , 2022. Building on the well-established seismic stratigraphy (Liu et al, 2019;2022), we utilized nine borehole cores and one gravity core (five newly acquired, five referenced from literature) (Table 1; Figure 1B) to establish seismic-to-core correlation and further examine the relationship between pollen and spore records and evolution of the prodelta stratigraphy.…”