南黄海中西部全新世地层沉积特征

Sedimentary characteristics of Holocene sediments in the Middle-Western South Yellow Sea

  • 摘要: 南黄海是典型的物源供给丰富的宽广陆架海,全新世沉积记录十分丰富,具有分辨率高、空间分布不连续和沉积记录片段性等特征。根据近年来在南黄海采集的大量高分辨率浅地层剖面资料,结合多个钻孔的岩性特征和AMS14C测年数据,较为系统精细地揭示了南黄海全新世沉积的时空分布特征。根据沉积体空间分布范围、成因机制和物质来源,南黄海全新世沉积可划分为4个独立的沉积体,呈现出不同的声学反射特征,主要为加积进积反射、平行或透明弱反射、中高角度进积反射和中高角度倾斜-斜交反射。根据估算,河流物质输入约占到南黄海全新世沉积总量的78%,其他物质来源主要为海侵过程中较强的海洋动力侵蚀、改造和再分配的底床物质。本文的研究可为厘清南黄海全新世沉积体精细演化过程的动力学机制研究提供更多可靠的证据。

     

    Abstract: The South Yellow Sea is a typical wide continental shelf sea with abundant terrestrial sediment supply. A variety of sedimentary records have been formed since the Holocene period, and they have characteristics in terms of high resolution, discontinuous spatial distribution, and depositional hiatus. Based on abundant high-resolution shallow seismic profiles acquired in the South Yellow Sea in recent years and combined with lithologic characteristics and AMS14C dating data of several cores, the spatial and temporal distribution of Holocene sediments in the South Yellow Sea were revealed systematically and meticulously. According to their spatial distribution, genetic mechanism and provenance, the Holocene sediments in the South Yellow Sea were divided into four independent sedimentary bodies, which show different acoustic reflection characteristics, including mainly accretion and aggradation reflection, parallel or transparent weak reflection, medium or high angle accretion reflection, and medium-high angle tilt-oblique reflection. By estimation, the river sediment input accounted for 78% of the Holocene sediments in the South Yellow Sea, and the other sources were mainly the bottom bed materials from strong marine dynamic erosion, transformation, and redistribution during transgression. The study is expected to provide more-reliable evidence for the research of dynamic mechanism of sedimentary evolution process of Holocene deposits in the South Yellow Sea.

     

/

返回文章
返回