2 ka以来山东半岛北部海域泥楔的稀土元素特征及物源识别  

Characteristics and provenance of rare earth element in mud wedge in the sea area north of Shandong Peninsula since 2 ka

作　　者：吴淑玉[1,2,3,4,5] 刘俊 冯永财[1] 常青 李佳林 远继东 李梦婷 宁伏龙 刘昌岭 宋轩[6] WU Shuyu;LIU Jun;FENG Yongcai;CHANG qing;LI Jialin;YUAN Jidong;LI Mengting;NING Fulong;LIU Changling;SONG Xuan(Yantai Center of Coastal Zone Geological Survey,China Geological Survey,Ministry of Natural Resources Observation and Research Station of Land-Sea Interaction Field in the Yellow River Estuary,Yantai 264000,China;School of Engineering,China University of Geoscience(Wuhan),Wuhan 430074,China;Key Laboratory of Submarine Geosicences,Ministry of Natural Resources,Hangzhou 310012,China;Chinese Academy of Geological Sciences,Beijing 100037,China;Laboratory for Marine Mineral Resources,Qingdao Marine Science and Technology Center,Qingdao 266237,China;College of Earth Science and Engineering,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]中国地质调查局烟台海岸带地质调查中心,自然资源部黄河入海口陆海交互作用野外科学观测研究站,烟台264000 [2]中国地质大学(武汉)工程学院,武汉430074 [3]自然资源部海底科学重点实验室,杭州310012 [4]中国地质科学院,北京100037 [5]青岛海洋科技中心海洋矿产资源评价与探测技术功能实验室,青岛266237 [6]山东科技大学地球科学与工程学院,青岛266590

出　　处：《海洋地质前沿》2024年第11期2-14,共13页Marine Geology Frontiers

基　　金：自然资源综合调查指挥中心科技创新基金“2.28 Ma年以来渤海西部古河道时空分布及有机碳埋藏成因研究”(KC20220011);自然资源部海底科学重点实验室开放基金“南黄海盆地中部隆起石炭纪—早二叠世非均质孔隙型碳酸盐岩储层刻画技术及油气潜力分析”(KLSG2304);中国地质调查局项目“1:25万威海幅海洋区域地质调查”(DD20230412),“渤海近海海域海岸带自然资源综合调查”(DD20230073),“渤海曹妃甸海域1:5万海洋区域地质调查”(DZ20220602)。

摘　　要：山东半岛泥楔是连接渤海和黄海的关键沉积体,在中国海域的沉积体系中占有重要地位,也是中国陆架边缘重要的“源-汇”体系中不可或缺的一环。通过分析位于山东半岛北部海域泥楔ZZ04柱状样的AMS^(14)C测年、沉积物粒度以及稀土元素含量等,探讨研究区稀土元素的控制因素以及泥楔沉积物的来源。结果表明,ZZ04柱状样的沉积物类型以粉砂为主,物质组分相对单一,在剖面上,粒度自下而上呈现由细至粗的变化过程。稀土元素经球粒陨石标准化后,显示出轻稀土富集而重稀土相对稳定的右倾“V”字型特征,为明显的陆源型特征。进一步将ZZ04与周围河流的稀土元素进行上陆壳标准化后对比分析可知,ZZ04与黄河的配分曲线较为相似,而与韩国河流以及山东半岛河流的配分曲线差异较大。此外,通过对稀土元素与粒度进行相关性分析,结合两者曲线的对比分析发现,2 ka以来,山东半岛泥楔的稀土元素分布受“粒度效应”的影响,泥楔的物源主要来自黄河。在现代海洋环流体系建立后,黄河携带的细粒沉积物沿着山东半岛北部沿岸流向东穿过渤海海峡进入黄海。在此过程中受到由南向北的黄海暖流的顶托作用,流速降低,导致大量细颗粒物质在山东半岛北部海域沉积,并形成“Ω”型的独特水下三角洲。The mud wedge in the Shandong Peninsula serves as a pivotal sedimentary body,linking the Bohai Sea with the Yellow Sea.It plays a significant role in the sedimentation system of China seas as an essential component of "source-sink" system in the edge of the Chinese continental shelf.The controlling factors of rare earth elements(REEs) and the provenance of the wedge sediment in this area were studied based on the analysis of AMS ~(14)C dating,grain size,and REEs content of the ZZ04 boxcore samples at the northern offshore of the Shandong Peninsula.Results indicate that the boxcore samples consist of mainly silty sand in relatively simple material composition with a trend of coarsening in grain size from deeper to shallower depths.Upon normalization with chondrites,the REEs exhibit a characteristic enrichment of light rare earth elements(LREEs) and relative stability of heavy rare earth elements(HREEs),forming a distinct right-leaning V-shaped pattern indicative of a clear terrigenous signature.Further comparative analysis on the REEs between the ZZ04 sample and surrounding rivers' after continental crust normalization revealed that the distribution patterns of ZZ04 samples closely resemble those of the Yellow River.In contrast,they show significant differences from those of the rivers in South Korea and the Shandong Peninsula.Additionally,correlation analysis between REEs and grain size suggested that the distribution of REEs in the mud wedge is influenced by the "grain size effect" since approximately 2,000 years ago.The source of the mud wedge comes mainly from the Yellow River.After the establishment of the modern ocean circulation system,the fine-grained sediments carried by the Yellow River flowed eastward along the northern coast of the Shandong Peninsula through the Bohai Strait into the Yellow Sea,and then encountered by the northward Yellow Sea Warm Current,which decreased the flow velocity and resulted in the settlement of a large amount of fine-grained matter in the northern waters of the Shandong Peni

关 键 词：山东半岛 粒度 稀土元素 泥楔 物源 

分 类 号：P736.4[天文地球—海洋地质]