Abstract High-resolution 2D seismic reflection profiles were examined to explore the stratigraphic architecture of the late Quaternary sediments deposited in the Beibu Gulf (SW off the Hainan Island, South China Sea). Two discontinuities identified in previous research by seismic reflectors R1 (top) and R2 (bottom) allowed to infer the presence of a paleodelta offshore Hainan Island. A detailed analysis of all discontinuities determined the extension of delta body, its thickness and spatial pattern of deltaic clinoforms. Analysis of data obtained by interpretation of seismic records allowed also to depict the relief of lower and upper delta surfaces identified by major erosional discontinuities. The seismic cross-sections provided tools with which to discern all the erosional incisions representing paleo-distributary channels of the delta on both surfaces. In addition, the delta geometry and clinoform dip angles were determined. Analyses have provided information on the direction of sediment transport and sources of deltaic sedimentary material. Distribution of vectors indicating the direction of delta progradation revealed the sediment transport from Hainan Island to be generally southwards to Yinggehai Basin and further towards the shelf edge, thus supporting the hypothesis of Hainan Island as the main source of sediment supply. The vector distribution is unclear in the westernmost part of delta body only, mainly because of an insufficient coverage of this part of the Gulf with seismic tracks and disturbances related to other sediment sources reaching Beibu Gulf in the north, which significantly contributed to the sediment supply.

中文翻译：

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基于地震剖面的海南岛西南北部湾晚更新世三角洲几何和沉积结构建模（南海）

摘要 研究了高分辨率二维地震反射剖面，以探索沉积在北部湾（南海海南岛西南）的晚第四纪沉积物的地层结构。先前研究中由地震反射器 R1（顶部）和 R2（底部）确定的两个不连续性允许推断海南岛近海古三角洲的存在。对所有不连续点的详细分析确定了三角洲体的延伸、其厚度和三角洲斜面的空间格局。对通过地震记录解释获得的数据进行分析，还可以描绘由主要侵蚀不连续性确定的三角洲下部和上部表面的起伏。地震剖面提供了识别代表三角洲两面古分流河道的所有侵蚀切口的工具。此外，还确定了三角洲几何形状和斜面倾角。分析提供了有关沉积物输送方向和三角洲沉积物质来源的信息。指示三角洲进积方向的向量分布表明，海南岛的泥沙运移总体上向南到莺歌海盆地，并进一步向陆架边缘移动，从而支持了海南岛为主要泥沙供应源的假设。仅在三角洲体最西端矢量分布不明确，