南黄海西部CSDP-01钻孔记录的全新世以来黄河入海的演化历史

The sediment supply of Yellow River and Yangtze River was one of the main factors controlling the sedimentation in the western South Yellow Sea since Holocene. Affected by N-S shifts of the Yellow River’s course, the source signals from the Yellow River and Yangtze River will change accordingly. Therefore, the identification of time series provenance variation of the western South Yellow Sea utilizing mineralogical and geochemical methods had important significance on revealing the evolution of the South Yellow Sea sedimentary system since Holocene, and determining the shifts of the Yellow River’s course and the distribution and evolution of the Old Yellow River delta. In this study, a comprehensive analysis of multi sediment tracers including major elements, rare earth elements and clay minerals will be conducted on the continuous drilling Core CSDP-01 located in the western South Yellow Sea for identifying the provenance of the western South Yellow Sea sediments since Holocene and revealing its variation. Based on the deeply identification of time series provenance variation of the western South Yellow Sea since Holocene, combined with the results of sedimentation rates, light and heavy minerals, and Sr, Nd isotope in the special layer of Core CSDP-01, we aimed to reveal the history of the Yellow River’s course shift and its impact on the deposition environment of the South Yellow Sea, and ascertain the age and history of the outside delta of South Yellow Sea, and thus provided an important basis for studying the history of the Yellow River and Yangtze River into the sea and its influence on the Yellow Sea continental shelf.

黄河和长江是控制全新世南黄海西部沉积作用的主要因素之一，受黄河改道影响，研究区沉积物中黄河和长江物源信号会发生相应变化，因此，从沉积矿物学和地球化学角度识别南黄海西部沉积物中黄河和长江物源的时间序列演化，对于揭示全新世南黄海沉积体系的演化过程、确定黄河改道历史及古黄河三角洲体系的空间分布与演化等都具有重要的科学意义。本研究拟通过对南黄海西部沉积记录连续的CSDP-01钻孔进行沉积物常量元素、稀土元素、粘土矿物等多示踪剂的综合分析，识别南黄海西部全新世以来沉积物的来源并揭示其变化规律；在深入查明全新世以来南黄海西部物源区时间序列演化的基础上，结合沉积速率和特征层位轻重矿物和Sr、Nd同位素在CSDP-01钻孔中的分布特征，揭示全新世以来黄河的改道历史及其对南黄海沉积环境的影响，查明南黄海外侧黄河三角洲的沉积年龄和发育演化历史，进而为研究黄河和长江的入海历史及其对黄海陆架的影响提供重要的依据。

黄河和长江是控制南黄海西部沉积作用的主要因素之一，受河流改道影响，研究区沉积物中黄河和长江物源信号会发生相应变化，因此，从沉积矿物学和地球化学角度识别南黄海西部沉积物中黄河和长江物源的时间序列演化，对于揭示南黄海沉积体系的演化过程、确定河流改道历史及古三角洲体系的空间分布与演化等都具有重要的科学意义。本研究通过对南黄海西部CSDP-01钻孔的前10米沉积物进行粘土矿物、轻重矿物及锶钕同位素多示踪剂的综合分析，结合光释光测年和AMS碳14测年结果，识别了南黄海西部氧同位素3期以来沉积物的来源并揭示了其变化规律。研究结果表明，氧同位素3期早期研究站位沉积物主要来自于长江，之后随着古三角洲向海进积，古黄河的影响不断增加，研究区氧同位素3期沉积物主要受到长江和黄河的共同影响；氧同位素1期由于受到长江冲淡水和黄河改道进入渤海的影响，研究区沉积物主要来自于长江，同时由于海底侵蚀作用的影响，研究区物源也受到先前沉积在南黄海陆架的黄河物质的影响。本研究通过沉积矿物学和地球化学的综合研究进一步揭示了氧同位3期黄河主要从南黄海入海，且氧同位素3期早期长江物质输入对南黄河的沉积具有重要影响，进而进一步限定了氧同位素3期时古长江三角洲的北界范围。这一研究对于阐明长江、黄河对大陆边缘沉积作用的影响、海陆相互作用的特点、再造古气候和古环境演变，都具有重要的科学意义。