全新世以来，长江下游地区频繁的人类活动与水文变化共同驱动了区域的复杂地貌演化，并对地层沉积过程的连续性产生影响，使得难以准确理解区域内史前文化的起源、发展与环境演变之间的关系。文章通过对长江下游地区新岗遗址沉积样品的采集，结合遗址内考古地层与自然钻孔的AMS14C测年结果，构建了自然沉积地层的年代学框架，并综合磁化
率、Mn/Ti、Fe/Mn等地球化学代用指标与粒度参数的分析，探讨了区域环境演变过程与文明演化之间的联系。结果表明，约7 ka BP（距今七千年）前后，遗址附近的沉积环境由水下沉积逐渐转变为陆地沉积；结合长江下游多个钻孔出现的沉积间断现象，认为长江三角洲在该时期逐渐形成，长江三角洲的形成为史前聚落提供了新的栖居地和农耕空间；7 ka BP后的干燥气候进一步扩大了利于耕种的土地面积。地貌—气候协同作用提高了土地生产力并支撑了人口的大规模增长，从而为马家浜—崧泽考古学文化的发展奠定了空间基础，并最终促成该地区进入了古国时代。

Complex geomorphological evolution in the lower reaches of the Yangtze River during the Holocene has been jointly driven by frequent human activities and hydrological changes, which affected the continuity of sedimentary processes
and complicated accurate understanding of the relationship between the origin and development of prehistoric cultures and environmental evolution in the region. In this study, we collected sedimentary samples from the Xingang site in the lower reaches of the Yangtze River and established a chronological framework for natural sedimentary strata based on archaeological stratigraphy and AMS14C dating of natural cores. Multiple proxy indices-including magnetic susceptibility, Mn/Ti, Fe/Mn, and grain-size parameters were analyzed to reconstruct regional environmental evolution and its linkage to cultural development. The results show a shift from an aquatic to a terrestrial sedimentary environment near the site around 7 ka BP. Together with sedimentary hiatuses identified in multiple cores across the region, this suggests the contemporary formation of the Yangtze River Delta. The emergence of the delta provided new habitats and agricultural space for prehistoric settlements. The drier climate after 7 ka BP led to further expanded arable land. This coupled geomorphic-climatic effect enhanced land productivity and supported substantial population growth, thereby laying the spatial foundation for the development of the Majiabang-Songze archaeological cultures and ultimately contributing to the rise of early state societies in the region.