海洋地质与环境重点实验室知识库

步入21世纪以来，为了更好地贯彻落实海洋强国战略与建设海上丝绸之路， 我国海洋开发技术不断升级优化，海洋综合工程、海洋矿产资源勘探倍道而进， 人们对海洋工程地质的调查需求激增，其中海底地形地貌与地层结构的勘察由 大面积扫测向区域化、精细化、高分辨率迈进。为了探明我国部分边缘海陆架、 陆坡等区域的地层地貌，本文依据采集的渤海中部海域、南海澎湖峡谷群、南 海珠江口盆地泥火山的高精度多波束水深数据、高分辨率浅地层剖面数据和部 分地球化学数据与地球物理数据，结合区域构造背景、水动力等条件与沉积物 历史资料，研究讨论了自浅水至深水环境中各海域典型地貌与地层结构，分析 其形态成因与演化过程，构建研究区海域的地貌-地层结构体系，为我国海洋的 开发利用提供基础的数据支撑与真实的科学指导作用。 高分辨率的水深地形图表明，渤海中部海域地形表现为南北两侧高，中间 低的特征。北部区域地形复杂，南部区域地形较平坦，根据海底地貌特点，将 研究区海底地貌单元划分为陆架侵蚀洼地、陆架堆积平原及海湾堆积平原。陆 架侵蚀洼地位于研究区中部，其形成与渤海古河系及现代潮流侵蚀作用有直接 的关系。陆架堆积平原主要位于研究区北部和南部，地形较平坦，主要受渤海 沿岸河流沉积物的堆积作用影响。研究区西部的海湾堆积平原，受控于泥沙等 沉积物的堆积作用。渤海中部海域长期以来受到地质构造运动、海平面变化、 现代海洋水动力以及沉积物的共同作用，塑造了近代渤海中部海底地貌格局。 基于最新的高保真度、高分辨率的多波束水深数据和浅地层剖面资料，对 南海澎湖峡谷群进行了区域分段研究，描绘了峡谷南北两段的地形地貌及浅地 层回波特征，并且分析峡谷的控制因素与形成过程。峡谷自北向南呈汇聚型， 北段峡谷区分支多，横剖面表现为“V”型，坡度较陡。北段峡谷侧壁上发育 大量冲沟、滑塌等地质现象，且浅地层回波呈现大量双曲线反射，说明海底环 境不稳定，冲刷仍在进行。南段峡谷区形成峡谷主干道，横剖面主要为“U” 型，地层表现为清晰层理。研究表明，澎湖峡谷群在构造挤压作用下形成了雏 形，海平面的变化加速了沉积环境的改变，促进了沉积物向海运输，北段峡谷 区积聚沉积物碎屑并且伴随着浊流等重力流向南段峡谷输送，控制着峡谷群的 阶段性发育。 根据高精度水深数据、地球物理资料与地球化学数据，探明了南海珠江口 盆地浅水区的泥火山形态特征与内部性质。我们认为研究区的泥火山沿断层发 育，且泥火山表面的坡度变化可能是由多期次喷发引起的，研究区出现的凹陷 是由流体渗流与底流活动共同导致。从 F 泥火山中采集到的由高方解石和低文石组成的碳酸盐矿物表明存在低甲烷泄漏环境。但δ13C的浓度在0~2 ‰之间， 表明碳源来自正常海水。这项研究为浅水区泥火山的演化特征和影响因素提供了启示。

Since the beginning of the 21st century, in order to better implement the strategy of building a maritime power and the construction of the Maritime Silk Road, China's marine development technology has been continuously upgraded and optimized. Marine comprehensive engineering and exploration of marine mineral resources have made great progress, and people's demand for marine engineering geology has surged. Among them, the exploration of seabed topography and geological structure has improved from rough large-scale scanning to localized investigation with high precision and resolution. In order to explore the stratigraphy and topography of marginal sea shelf, land slope and other areas, based on high-precision multi-beam bathymetric data, high resolution sub bottom profile data, and partial geochemical data, combines regional tectonic background, hydrodynamic conditions, and sediment column sample history data. It aims to investigate and discuss the typical landforms and stratigraphic structures of each sea area, analyze their morphological origins and evolutionary processes and construct a geomorphic stratigraphic structure system in the research area. This provides basic data support and scientific guidance for the development and utilization of China's oceans. The high-resolution seabed relief map shows that the topography of the central Bohai Sea is high in the north and south and low in the middle part. The terrain in the northern region is complex, while the terrain in the southern region is relatively flat. Based on the characteristics of the seabed topography, the seabed geomorphic units in the study area are divided into shelf erosion depression, shelf accumulation plain, and bay accumulation plain. The continental shelf erosion depression is in the central part of the study area, and its formation and evolution process are directly related to the activities of the ancient river systems and modern tidal currents in the Bohai Sea. The continental shelf accumulation plain is mainly located in the northern and southern parts of the study area, with a relatively flat terrain, and is mainly affected by the accumulation of sediment dilivered by the rivers along the Bohai Sea coast. The bay deposition plain in the western part of the research area is controlled by the accumulation of sediment. The central Bohai Sea has long been influenced by geological tectonics, sea level changes, modern ocean hydrodynamics, and deposition, which have shaped the main driving force of modern seabed topography. Using high-resolution multibeam data and sub-bottom profile data, we aim to accurately interpret the shallow stratigraphic profile of the Penghu Canyon Group in the South China Sea. This includes integrating sedimentary processes related to echo type inference and morphological characteristics. Furthermore, we will discuss the subtle changes in terrain and topography within the canyon, along with the potential mechanisms of turbidity current activity. The research area is divided into two sectionsalong the 1600 meter isobath, north and south. The northern section of the canyon area was characterized by widely distributed landslides and V-shaped gullies. The southern section of the canyon has a U-shaped profile and develops submarine fans. Multiple sub bottom profiles were collected from north to south in the research area. The part of the survey line that did not pass through the canyon in the east showed a Type IB pattern, with continuous reflections and parallel layers to the seabed, resulting in lower reflection intensity. Afterwards, the seabed tended to be gentle, and the reflection intensity decreased slightly. A large number of single curve reflections appeared on the canyon walls and top, indicating the high-energy sedimentation process in this area. On the westernmost side of the survey area, the continuous upward reflection characteristics along the seabed have once again transformed into Type IB, with clear bedding and regular wavy patterns, which are sediment waves and gradually weaken hydrodynamic forces. Based on acoustic data and geochemical data, the morphological characteristics and internal properties of mud volcanoes in the shallow water area of the Pearl River River Mouth Basin in the South China Sea are described, and it is believed that these mud volcanoes are developed along faults. The slope changes on the surface of mud volcanoes may be caused by multiple eruptions. We propose that the depression appearing in the study area is caused by a combination of fluid seepage and bottom flow activity. The carbonate minerals composed of high calcite and low aragonite collected from FM indicate the presence of a low methane leakage environment. The concentration of 13C is between 0~2 ‰, indicating that the carbon source comes from normal seawater. This study provides insights into the evolutionary characteristics and influencing factors of mud volcanoes in shallow water areas.

目 录 第1章 绪论 .............................................................................................. 1 1.1 选题背景与研究意义 .......................................................................................... 1 1.2 研究现状 .............................................................................................................. 2 1.2.1 水下声学探测技术研究现状 ....................................................................... 2 1.2.2 国内外水下地形地貌研究现状 ................................................................... 5 1.3 声学数据处理方法 .............................................................................................. 6 1.3.1 多波束测深数据处理方法 ........................................................................... 6 1.3.2 浅地层剖面仪数据处理方法 ....................................................................... 8 1.4 主要研究内容 ...................................................................................................... 8 第2章 渤海中部海域地形地貌特征及其影响因素 ............................10 2.1 前言 .................................................................................................................... 10 2.2 研究区地质概况 ................................................................................................ 10 2.3 技术方法 ............................................................................................................ 12 2.4 结果与讨论 ........................................................................................................ 13 2.4.1 海底地形特征 ............................................................................................. 13 2.4.2 海底地貌分类及浅地层剖面特征 ............................................................. 17 2.4.3 控制因素分析 ............................................................................................. 21 2.5 小结 .................................................................................................................... 23 第3章 澎湖峡谷群地形地貌与浅地层剖面特征 ................................24 3.1 前言 .................................................................................................................... 24 3.2 研究区地质概况 ................................................................................................ 25 3.3 技术方法 ............................................................................................................ 26 3.4 结果与分析 ........................................................................................................ 27 3.4.1 海底地形地貌分析 ..................................................................................... 27 3.4.2 浅地层剖面特征 ......................................................................................... 28 3.5 讨论 .................................................................................................................... 32 3.5.1 北段峡谷地形地貌与浅地层剖面特征成因 ............................................. 32 3.5.2 南段峡谷地形地貌与浅地层剖面特征成因 ............................................. 33 3.5.3 峡谷群控制因素分析 ................................................................................. 34 3.6 小结 .................................................................................................................... 35 第4章 珠江口盆地浅水区泥火山地形地貌特征 ................................36 4.1 前言 .................................................................................................................... 36 4.2 研究区地质概况 ................................................................................................ 36

4.3 技术方法 ............................................................................................................ 38 4.4 结果与分析 ........................................................................................................ 39 4.4.1 研究区地形地貌特征 ................................................................................. 39 4.4.2 FM浅地层剖面特征 .................................................................................. 41 4.4.3 FM磁力剖面特征 ...................................................................................... 41 4.4.4 碳酸盐岩拉曼光谱特征 ............................................................................. 42 4.4.5 碳酸盐岩XRD与碳氧同位素特征 .......................................................... 44 4.5 讨论 .................................................................................................................... 46 4.5.1 地形地貌控制因素 ..................................................................................... 46 4.5.2 FM浅地层与磁力剖面分析 ...................................................................... 46 4.5.3 碳酸盐岩地球化学特征指示沉积环境 ..................................................... 46 4.5.4 构造、断层、沉积物对泥火山演化的控制作用 ..................................... 49 4.6 小结 .................................................................................................................... 50 第5章 结论与展望 ................................................................................52 5.1 结论 .................................................................................................................... 52 5.2 展望 .................................................................................................................... 52 参考文献 ...................................................................................................54 致 谢 .........................................................................................................67 作者简历及攻读学位期间发表的学术论文与其他相关学术成果 ......68