Seismic stratigraphy of the quaternary Yellow River delta, Bohai Sea, eastern China


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Abstract

The upper 40 m of stratigraphy of the Yellow River (Huang He) subaqueous delta has been well documented, but the nature of the underlying strata is currently unknown at high-resolution. To address this deficiency we used a Geopulse seismic system to image shallow sedimentary deposits up to 120 m deep on the Yellow River delta. High-resolution seismic reflection images were processed with a series of specific techniques (e.g. swelling attenuation, dynamic s/n filter; f-x deconvolution, predictive deconvolution dipscan stack), and used with borehole data to investigate the Quaternary offshore sequences in the Yellow River (Huang He) delta. Repetitive sequences were observed and interpreted as containing layers of transgressive and regressive deposits. Six seismic transgressive and regressive cycles are identified. Unit M6F–C6F correlates with a relative sea-level rise (173–157 ka) and fall (231–173 ka), while Unit M5F–C5F is associated with a relative sea-level rise (124–100 ka) and fall (157–124 ka). Unit M4F–C4F spans a period of sea-level fall at 100–87 ka, followed by a rise at 87–76 ka. Unit M3F–C3F is a transgressive–regressive cycle dated as 76–58 ka. Unit M2F–C2F correlates with relative sea level fall at 58.2–36 ka and subsequent rise at 36–22 ka. Unit M1F–C1F was deposited during relative sea level fall (22–18 ka), followed by a rise, especially since 8.5 ka.

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