Polymetallic nodules (nodules) are a predominant deep-sea mineral resource due to theirenrichment with critical metals, such as Co, Ni, and Cu, and rare earth elements (REEs). The loose and porous nature of nodules contributes to their adsorption and enrichment in trace metals from seawater and pore water. Consequently, the specific surface area (SSA) of nodules is a key factor requiring further study. However, controls on the SSA of nodules with various genetic types remain poorly characterized. This study aimed to investigate controls on nodule SSA by analyzing the transition metals, REEs, mineralogy, and SSA of nodules recovered from basins in the Atlantic, Indian, and Pacific oceans, including the Northwest Pacific Basin (NPB), Bauer Basin (BB), Tiki Basin (TB), Wharton Basin (WB), Central Indian Basin (CIB), and Angola Basin (AB). Nodule SSAs were compared among the various basins by calculating the BET SSA (based on the equation proposed by Brunauer, Emmett, and Teller, 1938). The results suggest thatnodules from the PNB, WB, CIB, and AB are mainly hydrogenetic, and those nodules have a relatively high SSA, high Co, low Ni and Cu, positive Ce anomalies, and low X-ray diffraction (XRD) intensities at ~10 Å. The nodules from the BB and TB are mainly diagenetic in origin, characterized by a relatively low SSA, low Co, high Ni and Cu, negative Ce anomalies, and high XRD intensities at ~10 Å. The SSAs of nodules were significantly positively correlated with Co, δCe, and light REEs (LREEs), and negatively correlated with the XRD intensity at ~10 Å, Ni, and Cu. The SSAs of nodules from the NPB ranged from 329.440 m²/g to 418.711 m²/g, comparable to the SSAs of Co-rich crusts on seamounts. This study proposes that nodule SAA is regulated by nodule genesis and that hydrogenetic nodules have a higher SSA.

During winter, strong winds and waves significantly enhance sediment resuspension in the Yellow River Delta. Based on the continuous and high-resolution data on water levels, wave heights, current velocities, and echo intensities collected by the Acoustic Doppler Current Profiler at different depths (5 m and 12 m) in the northern Yellow River Delta simultaneously, this study investigated the sediment resuspension during gale events and tranquil conditions. In deeper waters (12 m), the suspended sediment volume concentration (SSVC) showed a strong correlation with current speed (r = 0.74), while in shallower waters (5 m), the SSVC correlated more closely with wave height (r = 0.72). The thorough analysis of gale events revealed that the maximum wave heights during northwest gales were 23.80% and 34.59% lower than that during northeast gales at deep and shallow stations, respectively, primarily due to the longer wind fetch associated with northeast gales. Conversely, the maximum current velocities during northwest gales were 10.34% and 37.31% higher than that during northeast gales at deep and shallow stations. In deeper waters, the maximum wave–current induced shear stress $({\tau }_{cw}$) and SSVC during northwest gales were 30.38% and 3.70% higher than those during northeast gales, highlighting current-driven resuspension. In contrast, in shallower waters, the maximum ${\tau }_{cw}$ and SSVC during northeast gales were 47.35% and 4.94% higher than those during northwest gales, underscoring the dominance of wave-induced resuspension.

Quaternary climate has been characterized by pronounced glacial–interglacial cycles, with eustatic sea-level fluctuations directly controlling coastal sedimentary environments. The Yellow River Delta, situated on the southwestern coast of Bohai Bay, bears a distinct stratigraphic imprint of marine–terrestrial environmental transitions. However, critical knowledge gaps persist in reconstructing an integrated continental–marine stratigraphic framework. This study focuses on the nearshore core CB2302, integrating sediment lithology, grain size, foraminiferal assemblages, and geochemical proxies to establish a regional stratigraphic chronology since MIS5. Three depositional units (DU1–DU3) and 12 sedimentary subunits (C1–C12) were identified based on grain-size distributions, geochemical signatures, hydrodynamic, and microfossil assemblages. Integration of AMS ¹⁴C dating and sequence stratigraphic analysis establishes a post-MIS 5 stratigraphic framework for the northern Yellow River Delta, revealing sedimentary responses to three transgressive–regressive cycles (MIS 5e, 5c, and 5a) and confirming widespread terrestrial deposition during MIS 4–2, with no detectable marine influence in MIS 3 strata. Furthermore, correlation with representative cores across the Yellow–Bohai Sea coastal system elucidates a unified model of shoreline migration patterns driven by post-MIS5 sea-level oscillations. These findings advance the understanding of Quaternary sediment–landscape interactions in deltaic systems and provide critical stratigraphic benchmarks for petroleum exploration and coastal engineering in active depositional basins.

Holocene deposits in the northern Yellow River Delta were jointly controlled by sea-level change, Yellow River sediment supply, channel avulsion, marine hydrodynamics and East Asian monsoon variability. These superimposed controls make environmental interpretations based on a single grain-size or geochemical proxy inherently ambiguous. We investigated the upper 20 m of nearshore core CB2302 by integrating AMS ¹⁴C ages, historical channel events, modern bathymetric change, shallow-seismic correlation, grain-size end-member modelling and geochemical proxies. The base of the first marine layer occurs at 19.67 m and is assigned an age of ca. 9300 a BP. The 15.37 m horizon correlates with a tidal-channel migration event in nearby core HB-1, whereas the boundary at 4.14 m records the 1855 Yellow River avulsion into Bohai Bay. The upper 0-2 m comprises residual deposits left after rapid accumulation during the Diaokou course and subsequent erosion. Four grain-size end members were identified using facies position and independent proxies to constrain their meanings. EM1 represents background suspension fallout under relatively low-energy conditions; EM2 represents recurrent fine-silt transport by coastal circulation and resuspension; EM3 marks episodic high-energy reworking; and EM4 records facies-dependent coarse transport, with a proximal Yellow River signal above 4.14 m. The integrated record defines four stages since ca. 9300 a BP: a tidal-flat/channel transition, stable shallow-marine sedimentation, middle-late Holocene shallow-marine deposition modulated by monsoon and event processes, and post-1855 delta progradation followed by erosional reworking. Because age control is uneven, centennial-to-millennial comparisons are interpreted as qualitative trends rather than precise quantitative correlations. The results demonstrate that process separation and independent proxy constraints are essential when extracting climate information from a rapidly evolving, river-dominated shelf system.

Holocene deposits in the northern Yellow River Delta were jointly controlled by sea-level change, Yellow River sediment supply, channel avulsion, marine hydrodynamics and East Asian monsoon variability. These superimposed controls make environmental interpretations based on a single grain-size or geochemical proxy inherently ambiguous. We investigated the upper 20 m of nearshore core CB2302 by integrating AMS ¹⁴C ages, historical channel events, modern bathymetric change, shallow-seismic correlation, grain-size end-member modelling and geochemical proxies. The base of the first marine layer occurs at 19.67 m and is assigned an age of ca. 9300 a BP. The 15.37 m horizon correlates with a tidal-channel migration event in nearby core HB-1, whereas the boundary at 4.14 m records the 1855 Yellow River avulsion into Bohai Bay. The upper 0-2 m comprises residual deposits left after rapid accumulation during the Diaokou course and subsequent erosion. Four grain-size end members were identified using facies position and independent proxies to constrain their meanings. EM1 represents background suspension fallout under relatively low-energy conditions; EM2 represents recurrent fine-silt transport by coastal circulation and resuspension; EM3 marks episodic high-energy reworking; and EM4 records facies-dependent coarse transport, with a proximal Yellow River signal above 4.14 m. The integrated record defines four stages since ca. 9300 a BP: a tidal-flat/channel transition, stable shallow-marine sedimentation, middle-late Holocene shallow-marine deposition modulated by monsoon and event processes, and post-1855 delta progradation followed by erosional reworking. Because age control is uneven, centennial-to-millennial comparisons are interpreted as qualitative trends rather than precise quantitative correlations. The results demonstrate that process separation and independent proxy constraints are essential when extracting climate information from a rapidly evolving, river-dominated shelf system.