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摘要: 【目的】北部湾北部是东亚夏季风、印度季风以及蒙古冷高压影响的交汇处，对气候变化敏感，该区沉积物要素在全新世的分布与变化，可反映该区气候波动特征和海岸格局演进之影响因素。【方法】在北部湾北部广西水域依次钻取 3 孔岩芯并进行粒度、矿物、元素、微体古生物测试鉴定以及14C 测年，综合分析对比沉积物要素的垂直分布、变化以及响应特征。【结果】全新世孢粉组合为热带-亚热带山地组合。岩芯粒度波动旋回变化，经历了自河床向浅海湾的变迁，沉积物具有陆源性，元素等几乎与沉积旋回细组分同步变化。早期三角洲盆地钻孔显示为盐沼环境；相对晚更新世或者末期，全新世早期沉积物颗粒粗减细增，有机质增幅超过 700%。碎屑矿物种类增加，孢粉和硅藻化石逐步丰富，硅藻属种数也保持增加趋势，沉积速率为全新世平均值的 1.36~1.85 倍，具有风化较强、水沙丰沛、沉积快、物质分配活跃、生物较为繁盛的特点，与邻区全新世早期气候适宜期相符合。早期气候仍然波动，可辨认出 8.2 ka BP 小冷期事件的影响，Sr/Ba 比值偏低。【结论】研究区作为东亚低纬度季风区海陆过渡界面，其环境变化与气候变化相联系，对气候变化的响应比较敏感，上述小冷期具有作为气候调整而为下一步海侵积聚能量的意义。
Abstract: 【Objective】 Northern Beibu Gulf is the intersection of East Asian summer monsoon, Indian monsoon and Mongolian cold pressure. It is sensitive to climate change. The distribution and variation of sediment elements in the area during Holocene reflect the characteristics of climate fluctuation in this area. Factors Affecting the Evolution of Coastal Pattern. 【Method】 Three cores were drilled in Guangxi Bei Bei Bay in sequence and tested by means of particle size, mineral, elemental and microscopic paleontology and 14C dating. The vertical distribution, variation and response characteristics of sediment elements were analyzed and compared comprehensively. 【Result】 The Holocene sporopollen assemblage is a tropical-subtropical mountainous assemblage. The granulometric fluctuation of the core varies cyclically, experienced the change from the river bed to the shallow bay. The sediments are of terrigenous origin and the elements are almost synchronous with the sedimentary cycle. Early Delta basin boreholes show salt marsh environment; relatively late Pleistocene or late, early Holocene sediment particle size reduction increased by fine, organic matter increased by more than 700%. The types of detrital minerals increased, the sporopollen and diatom fossils were gradually enriched, and the number of diatoms also increased. The deposition rate was 1.36-1.85 times that of the Holocene, with a strong weathering, abundant water and sediments, quick deposition, Active material distribution, more prosperous biological characteristics, and the adjacent area of the Holocene climate adaptation period is consistent. The early climate still fluctuated, and the effect of a small cold event at 8.2 ka BP was identified, with a low Sr / Ba ratio. 【Conclusion】 As a land-sea transitional interface in the low-latitude monsoon region of East Asia, the study area is related to climate change and is sensitive to climate change. The above-mentioned small cold period has the significance of adjusting the energy for the next step of transgression .