西朝鲜湾潮流沙脊的地质特征及其形成演化机制

中国东部陆架广泛发育潮流沙脊，其发育和演化过程是我国陆架边缘海环境演化的重要部分。西朝鲜湾潮流沙脊位于北黄海东部，属开敞型海湾沙脊，与东海陆架和江苏岸外等开阔陆架沙脊相比，具有鲜明的特色，但尚未开展实质性的研究。本项目拟选取西朝鲜湾潮流沙脊为研究对象，通过点(表层和岩芯沉积物、定点海流观测)-线(浅地层剖面)-面(多波束测深和侧扫声纳)三位一体的研究，刻画西朝鲜湾潮流沙脊的三维精细结构和海底微地貌特征，揭示其沉积动力机制；构建该海域晚第四纪以来具有年代地层格架的层序地层模式，揭示西朝鲜湾潮流沙脊的时空发育规律；阐明西朝鲜湾潮流沙脊的形成演化对海平面变化及区域"源-汇"效应的响应关系。研究成果将是开敞型海湾沙脊成因模式和演化机制的有益补充，有助于全面了解晚第四纪以来我国东部陆架的环境演化史，并为研究区工程建设、砂矿开采等提供科学依据。

The genesis and evolution of tidal sand ridges in the East China Seas Shelf provide critical insights into the paleoenvironmental evolution history of this shallow epicontinental shelf. The tidal sand ridges of West Korea Bay are typical wide estuary (bay) sand ridges, which are different with the sand ridges in the East China Sea shelf and Jiangsu offshore area. Currently, theories relevant to wide estuary (bay) sand ridges are still primitive, and details of the evolution model associated with the sea-level changes have remained poorly understood. In this proposal, on the basis of multibeam bathymetric and side scan sonar data, hydrodynamic measurements, high-resolution shallow seismic profiles, surface and core sediments data, we will decipher in detail the internal sedimentary architecture and the spatio-temporal distribution of the West Korea Bay tidal sand ridges.The high-resolution seismic data combined with geotechnical boreholes and shallow cores will be used to reconstruct the late Quaternary depositional history and chronostratigraphic framework, and then to reveal the genesis and evolution model of the West Korea Bay tidal sand ridges related to sea-level changes. This case study would provide deeper insights into the formation and evolution mechanisms of the wide estuary (bay) sand ridges, and can also be helpful to improve our knowledge of the late Quaternary geological history of the East China Seas shelf.