| 表层沉积物粒度所指示的渤海现代沉积体系 |
| |
| 引用本文： | 秦亚超, 李日辉. 表层沉积物粒度所指示的渤海现代沉积体系[J]. 第四纪研究, 2017, 37(3): 654-666. doi: 10.11928/j.issn.1001-7410.2017.03.20 |
| |
| 作者姓名： | 秦亚超 李日辉 |
| |
| 作者单位： | 国土资源部海洋油气资源与环境地质重点实验室, 青岛 266071; 青岛海洋地质研究所, 青岛 266071 |
| |
| 基金项目： | 国土资源部海洋区域地质调查项目（批准号：1212011220113和GZH201400206）资助 |
| |
| 摘 要： | 本文基于140个渤海表层沉积物样品的粒度分析，探讨渤海的现代沉积体系。结果表明，渤海现代沉积体系主要分为三类：1）渤东潮流沉积体系，以潮流动力作用为主，包括渤东涨潮流三角洲及其前缘的泥质沉积，以及该三角洲以北的变余沉积和残留沉积；2）河流水下三角洲沉积，以河流与海洋动力交互作用为主，主要包括黄河水下三角洲、滦河水下三角洲、辽河水下三角洲、海河水下三角洲和潍河-弥河水下三角洲等；3）陆架沉积，其中，渤海湾中部发育陆架泥质沉积。渤海东部涨潮流三角洲沉积体呈较为完整的扇形分布，扇形中轴大致由老铁山水道强潮流速区指向秦皇岛至滦河口近海的弱潮流速区，其三角洲前缘发育泥质沉积。渤东涨潮流三角洲以北存在一块面积较大的古河流相沉积洼地，由于周边碎屑物质供应匮乏，尚未被现代沉积物明显覆盖，估计应为渤海面积较大的一处变余沉积-残留沉积区。渤海泥质区（带）由渤海湾内的陆架泥质沉积和渤东涨潮流三角洲的前缘泥质沉积相互叠加、衔接而成。从物源上来看，该泥质区（带）由黄河（再）悬浮的细颗粒物质长期、缓慢沉降堆积而成，由此也构成了黄河物质向北扩散的边界。模式分析显示，落潮流可能是黄河物质向北黄海搬运的主要驱动力。
|
| 关 键 词： | 粒度 表层沉积物 涨潮流三角洲 沉积体系 渤海 |
| 收稿时间： | 2016-10-17 |
| 修稿时间： | 2017-02-22 |
IMPLICATIONS OF SURFACE SEDIMENT GRAIN SIZE FOR THE DEPOSITIONAL SYSTEMS IN THE BOHAI SEA |
| |
| Qin Yachao, Li Rihui. IMPLICATIONS OF SURFACE SEDIMENT GRAIN SIZE FOR THE DEPOSITIONAL SYSTEMS IN THE BOHAI SEA[J]. Quaternary Sciences, 2017, 37(3): 654-666. doi: 10.11928/j.issn.1001-7410.2017.03.20 |
| |
| Authors: | Qin Yachao Li Rihui |
| |
| Affiliation: | Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology, Ministry of Land and Resources, Qingdao 266071; Qingdao Institute of Marine Geology, Qingdao 266071 |
| |
| Abstract: | Grain-size analysis was carried out for 140 surface sediment samples collected from the Bohai Sea to discriminate sediment provinces and to explain the distributions of grain-size parameters observed. A sedimentation pattern is used to describe the tidal current induced modern depositional systems in the Bohai Sea. Results show that silt is the main component of surface sediments, with an average of 60.9%. Clay and sand concentrations average 21.6% and 17.6%, respectively. The major sediment types include sandy silt, silt, and silty sand, based on Folk's classification system. The modern Bohai depositional systems are classified into 3 categories:(1) The eastern Bohai tidal delta system dominated by tidal dynamics, including the eastern Bohai flood-tidal delta and its front mud deposit as well as palimpsest and relict deposit occurred to the north of this flood-tidal delta; (2) Fluvial subaqueous deltas dominated by interaction of fluvial and marine dynamics, mainly including those deltas of the Yellow, Luanhe, Liaohe, Haihe and Weihe-Mihe rivers; (3) Continental shelf deposits, among which mud deposit has developed in the central Bohai bay due to weak hydrodynamic conditions. The eastern Bohai flood-tidal delta is present in almost completely fan-like appearance, with an axis roughly from the Laotieshan channel characterized by strong tidal currents to an offshore regime between Qinhuangdao and the Luanhe river mouth, where the tidal currents are invariably weak. Mud deposit develops in front of this flood-tidal delta, extending in SW-NE direction. There is a large depression deposited by paleo-fluvial sediments to the north of the eastern Bohai flood-tidal delta. It is speculated as a large palimpsest to relict deposit, because it has not covered obviously by Holocene sediments due to poor supply of terrigenous detritus from surrounding areas. The Bohai mud area/zone is comprised of the mud shelf deposit in the Bohai bay combined with the delta front of the eastern flood-tidal delta. This mud area/zone is built up by long-term slow settling of(re-)suspended fine-grained particles from the Yellow River and thus forms the northernmost dispersal boundary of the Yellow River derived materials. Pattern analysis suggests that ebb-tidal currents are likely to be an important hydrodynamics transporting Yellow River derived materials eastward to the northern Yellow Sea. |
| |
| Keywords: | grain size surface sediment flood-tidal delta depositional system Bohai Sea |
|
| 点击此处可从《第四纪研究》浏览原始摘要信息 |
|
点击此处可从《第四纪研究》下载全文 |
|
