泸沽湖表层沉积物粒度空间分布特征及其影响因素
发布时间：2018-10-30 14:39
【摘要】：选择位于青藏高原和云贵高原过渡区的泸沽湖作为研究对象,对南部主湖区70个表层沉积物样品进行了粒度分析,结合湖泊周围自然地理要素,探讨了粒度各组分在空间上的分布特征及其影响因素。结果表明:泸沽湖南部主湖区表层沉积物沉积类型以黏土质粉砂为主,少数样品为砂质粉砂、砂,砾石主要分布在研究区南部和北部湖滨带,其中粉砂是该研究区的优势粒级。另外,南部主湖区表层沉积物粒度各组分分布具有明显的空间差异性,其中研究区东南侧及西南侧由于受入湖河流(山跨河、三家村河)的影响,导致黏土组分呈舌状分别向北、向东北方向延伸,但东南侧由于受湖水外流形成的定向湖流顶托作用,对研究区物源的贡献较弱;研究区西北部砂组分由于受到悬移作用和定向湖流影响,由西北向东南方向凸出;由于受反时针环流作用的影响,大量细粒物质由研究区北部和西南侧悬移至研究区南部并沉积下来,使得此处有大量细物质沉积。同时指出,泸沽湖南湖表层沉积物粒度空间分布的差异性特征受控于湖泊沉积动力过程及沉积物对环境变化响应敏感程度的差异,研究湖泊表层沉积物粒度组成不仅对于认识湖泊水动力及物质输入状况有很大的促进作用,对合理选择钻孔岩芯位置、开展湖泊沉积古气候环境变化研究具有一定的参考意义。
[Abstract]:Lugu Lake, which is located in the transitional area of Qinghai-Tibet Plateau and Yunnan-Guizhou Plateau, is selected as the research object. The grain size of 70 surface sediment samples in the southern main lake region is analyzed, and the physical and geographical elements around the lake are combined. The spatial distribution characteristics of granularity components and their influencing factors were discussed. The results show that the sedimentary types of surface sediments in the southern Lugu Lake are mainly clay silt, a few samples are sandy silt, and gravel is mainly distributed in the southern and northern lakeshore zones of the study area, among which silt is the dominant grain-size of the study area. In addition, the distribution of grain size components of surface sediments in the southern main lake area showed obvious spatial differences, among which the southeast and southwest sides of the study area were affected by the rivers entering the lake (Shancross River, Sanjiacun River). The results show that the clay components are tongue shaped to the north and to the northeast, but the southeastern side has a weak contribution to the provenance of the studied area due to the topping action of the directional lake flow formed by the outflow of the lake water. The sand components in the northwest of the study area are protruded from northwest to southeast due to the effects of suspended movement and directional lake flow. Due to the influence of counterclockwise circulation, a large number of fine particles were suspended from the north and southwest of the study area to the southern part of the study area and deposited, resulting in a large amount of fine material deposition. At the same time, it is pointed out that the difference in the spatial distribution of surface sediments in Lugu Lake is controlled by the dynamic processes of sediments and the sensitivity of sediments to environmental changes. The study of grain size composition of lake surface sediment is not only helpful to understand the hydrodynamic force and material input of lake, but also has certain reference significance to reasonably select the core location of borehole and to study the paleoclimate environment change of lake sediment.
【作者单位】： 云南师范大学旅游与地理科学学院/高原湖泊生态与全球变化重点实验室/高原地理过程与环境云南省重点实验室;
【基金】：国家自然科学基金(41361008) 云南省高端人才引进项目(2010CI111) 湖泊沉积与环境变化云南省创新团队项目(2010CI)~~
【分类号】：P512.2
本文编号：2300285
[Abstract]:Lugu Lake, which is located in the transitional area of Qinghai-Tibet Plateau and Yunnan-Guizhou Plateau, is selected as the research object. The grain size of 70 surface sediment samples in the southern main lake region is analyzed, and the physical and geographical elements around the lake are combined. The spatial distribution characteristics of granularity components and their influencing factors were discussed. The results show that the sedimentary types of surface sediments in the southern Lugu Lake are mainly clay silt, a few samples are sandy silt, and gravel is mainly distributed in the southern and northern lakeshore zones of the study area, among which silt is the dominant grain-size of the study area. In addition, the distribution of grain size components of surface sediments in the southern main lake area showed obvious spatial differences, among which the southeast and southwest sides of the study area were affected by the rivers entering the lake (Shancross River, Sanjiacun River). The results show that the clay components are tongue shaped to the north and to the northeast, but the southeastern side has a weak contribution to the provenance of the studied area due to the topping action of the directional lake flow formed by the outflow of the lake water. The sand components in the northwest of the study area are protruded from northwest to southeast due to the effects of suspended movement and directional lake flow. Due to the influence of counterclockwise circulation, a large number of fine particles were suspended from the north and southwest of the study area to the southern part of the study area and deposited, resulting in a large amount of fine material deposition. At the same time, it is pointed out that the difference in the spatial distribution of surface sediments in Lugu Lake is controlled by the dynamic processes of sediments and the sensitivity of sediments to environmental changes. The study of grain size composition of lake surface sediment is not only helpful to understand the hydrodynamic force and material input of lake, but also has certain reference significance to reasonably select the core location of borehole and to study the paleoclimate environment change of lake sediment.
【作者单位】： 云南师范大学旅游与地理科学学院/高原湖泊生态与全球变化重点实验室/高原地理过程与环境云南省重点实验室;
【基金】：国家自然科学基金(41361008) 云南省高端人才引进项目(2010CI111) 湖泊沉积与环境变化云南省创新团队项目(2010CI)~~
【分类号】：P512.2
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