九州-帕劳海脊南段及邻近海域表层沉积物元素地球化学特征及其地质意义  

Elemental geochemical characteristics of surface sediments from the southern Kyushu-Palau Ridge and their geological significance

作　　者：丁雪 胡邦琦[1,2] 赵京涛 王飞飞 黄威 李攀峰 刘佳[1,3] 郭建卫 崔汝勇[1] DING Xue;HU Bangqi;ZHAO Jingtao;WANG Feifei;HUANG Wei;LI Panfeng;LIU Jia;GUO Jianwei;CUI Ruyong(Qingdao Institute of Maine Geology,CGS,Qingdao 266237,China;Laboratory for Marine Mineral Resources,Laoshan Laboratory,Qingdao 266237,China;College of Marine Geosciences,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国地质调查局青岛海洋地质研究所,青岛266237 [2]崂山实验室海洋矿产资源评价与探测技术功能实验室,青岛266237 [3]中国海洋大学海洋地球科学学院,青岛266100

出　　处：《海洋地质与第四纪地质》2023年第1期61-70,共10页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金面上项目“菲律宾海盆底层水体性质对中更新世气候转型的响应机制”(41976192);中国地质调查局地质调查二级项目(DD20191010,DD20221720);黄土与第四纪国家重点实验开放基金(SKLLQG1805);中国科学院B类战略性先导科技专项(XDB40000000)。

摘　　要：菲律宾海地理位置特殊,蕴含着丰富的前沿地球科学问题,是研究地球多圈层相互作用的天然实验室。近年来,菲律宾海中部九州-帕劳海脊南段已成为研究热点,但对其表层沉积物物质来源和沉积环境了解尚存在不足。本文通过对采集于九州-帕劳海脊南段水深为3 900~6 100 m的69个站位样品开展沉积地球化学研究,旨在判别沉积物的物质来源和沉积环境空间变化特征。结果表明:研究区底质类型为远洋黏土和硅质软泥,不同类型沉积物的碎屑组分化学风化程度均较低,受分选和再循环的影响较小,是亚洲风尘物质和岛弧火山物质的混合产物,且以亚洲风尘物质为主;研究区不同类型站位的沉积环境基本一致,整体处于氧化沉积环境,底层水体氧化还原条件不是研究区沉积物中过渡金属(如Mo)元素富集的控制因素,铁锰(氢)氧化物是连接水体-沉积物中过渡金属元素源-汇过程的重要纽带。此外,底部氧化还原条件可能不是该海域硅藻席沉积保存的必要条件。The Philippine Sea, with its special geographical location, is rich in frontier geoscience issues and is a natural laboratory for studying the Earth multi-layer interactions. In recent years, the southern section of the Kyushu-Palau Ridge in the central Philippine Sea has become a hot spot for geoscience research, but its surface sediment provenance and sedimentary environment are not yet well understood. The sediment geochemistry of 69 stations collected from the southern section of the Kyushu-Palau Ridge at water depths of 3 900-6100m was studied to identify the spatial variability of sediment provenance and depositional environments. The results show that the sediment types in the study area are pelagic clay and siliceous ooze, and the clastic components of sediment are less chemically weathered, less affected by sorting and recycling,and are mixed products of Asian dust materials and island-arc volcanic materials, of which Asian dust materials are dominated;and the different types of sediment in the study area are basically in an oxidative depositional environment, and the bottom water redox conditions are not a controlling factor for the enrichment of transition metal(e.g., Mo) elements in the sediments, indicating that Fe-Mn(oxyhydr)oxides are an important link between the source-sink processes of transition metal elements at the water-sediment interface. In addition, bottom redox conditions may not be necessary for the preservation of diatom mats.

关 键 词：表层沉积物 元素地球化学 源汇过程 氧化还原敏感元素 九州-帕劳海脊 

分 类 号：P736.4[天文地球—海洋地质]