三角洲地区不同粒径沉积物磁性特征研究，是揭示古环境变化的重要手段，对理解海平面和全球气候变化有重要意义。目前，关于三角洲地区不同粒径沉积物磁性特征及其对古环境变化的响应机制尚不清楚。本项目选择长江三角洲北翼YZ07钻孔为研究对象，以磁学为主要研究方法，辅以其他气候和环境指标，综合分析全样和不同粒径沉积物磁性矿物特征，厘清影响磁性矿物的主要因素，揭示磁性矿物与不同粒径的富集关系，明晰不同粒径的磁性贡献，探讨磁性矿物的古环境信息。主要研究内容包括：（1）全样沉积物磁性矿物特征及影响磁性矿物的主要因素；（2）不同粒径沉积物的磁学性质、富集关系与磁性贡献；（3）全样和不同粒径沉积物磁性矿物的古环境变化信息。研究成果有助于拓展环境磁学在长江三角洲沉积与环境方面的研究，同时对理解磁指标的古环境变化响应机制具有重要的科学意义和参考价值。

It is an important means of revealing paleoenvironmental variation to study the magnetic characteristics of sediments with different grain sizes in Delta regions, and this is of great significance in understanding the changes of sea level and global climate. However, it is poorly understood for how the magnetic characteristics of sediments with different grain sizes responded to paleoenvironmental variation in Delta regions. Thus, with Borehole YZ07 in the north wing of the Yangtze River Delta as an object of study, by using magnetism as a main research approach, we make a comprehensive analysis on the magnetic mineral characteristics of the bulk sample and sediments with different grain sizes based on various other climatic and environmental indexes in an attempt to investigate the major factors influencing magnetic minerals, reveal the correlation between magnetic mineral accumulation and different grain sizes, and clarify the paleoenvironmental information of magnetic minerals. The main research contents include: (1) the magnetic mineral characteristics of the bulk samples and the major factors influencing magnetic minerals; (2) the magnetic properties and magnetic contributions of the sediments with different grain sizes, as well as the correlation between them in terms of enrichment; (3) the paleoenvironmental variations information of magnetic minerals in the bulk samples and sediments with different grain sizes. The study results can contribute to further research of sedimentation and environment by environmental magnetism in the Yangtze River Delta, and serve as an important scientific reference for an understanding of how magnetic indexes responded to paleoenvironmental variations.