东海浪岗山岛屿黄土的粒度与磁性特征及其环境意义  

PRIMARY RESEARCH ON THE MATERIAL SOURCE OF AEOLIAN-DUST DEPOSITION AT LANGGANGSHAN ISLAND OF EAST CHINA SEA

作　　者：刘飞[1] 郑祥民[1] 许健[1] 曹希强[2] 

机构地区：[1]华东师范大学地理系教育部地理信息科学重点实验室,上海200062 [2]河南省国土资源科学研究院,郑州450053

出　　处：《海洋地质与第四纪地质》2005年第4期93-98,共6页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目(40372135)

摘　　要：通过对东海浪岗山岛屿黄土剖面系统采样和粒度、磁化率测试,在同其他地方黄土充分对比的基础上,分析和讨论了浪岗山第四纪风成沉积的粒度与磁性特征:浪岗山黄土剖面中,10～50 μm粒组富集,分布均匀,符合黄土的风成特性;但粗颗粒(>50 μm)含量均超过10%,显示该剖面除了接受来自西北内陆的远源风尘物质外还接受来自东海陆架的近源风尘物质;磁化率相对较高,但变化不大.根据沉积物的粒度与古气候环境的内在联系,结合磁化率变化情况,对该地区风尘沉积物的物源变迁及环境演变进行了初步探讨和分析.On the basis of systematic sampling and testing of grain-size and susceptibility, the grain-size features of Quaternary aeolian-dust deposition distributed at Langgangshan Island in East China Sea, are analyzed and discussed in this paper. The Aeolian-dust deposition on Langgangshan Island mainly consists of fine particles（10-50 μm） and is similar to the component of loess in other sections of China but comparatively coarser. The content of coarse particles（〉 50 μm） on Langgangshan Island section is over 10% which indicates that the material sources contain proximal aeolian-dust from shelf area of East China Sea besides distant aeolian-dust from Northwest China. Susceptibility is higher but varies not sharply. The tidal sediments of paleo-Yangtze Estuary provided the proximal materials for aeolian loess under the given climate. The conclusion will renew the research of islands loess and paleoenvironment development of East China Sea. The mode and course of Quaternary aeolian-dust deposit on the shelf of East China Sea during the last glacial period are discussed in the paper at the same time.

关 键 词：风成沉积 粒度 磁化率 浪岗山列岛 东海 

分 类 号：P539[天文地球—古生物学与地层学]