| 摘要: |
| 沉积物粒级包含了大量的沉积环境信息, 在古环境恢复和重建中被广泛应用。基于采自东海内陆架的三根沉积物岩芯, 作者利用激光粒度分析方法研究了沉积物的粒度组成, 确定了敏感性粒级, 探讨了搬运机制及其环境意义。研究表明: 东海内陆架现代沉积物含有大致相同的三个敏感性粒级, 分别是粒级1(<12μm)、粒级2(12-225μm)和粒级3(>225μm)。从北到南敏感粒级具有逐渐细化的趋势, 该趋势与长江入海沉积物向南搬运过程中发生的沉积分异作用有关。粒级1和粒级2分别由均匀悬浮次总体和递变悬浮次总体构成, 而粒级3则由生物过程产生。结合该区的海洋动力特征, 作者认为, 粒级2可较好地用来指示冬季海洋动力强度, 并具有揭示东亚冬季风强度的潜在意义。 |
| 关键词: 东海内陆架 沉积物 敏感性粒级 搬运机制 替代性指标 |
| DOI：10.11693/hyhz20150500140 |
| 分类号: |
| 基金项目:国家自然科学基金项目, 41376055号; 国家重大基础研究发展计划(973)项目, 2010CB951202号。 |
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| SENSITIVE GRAIN SIZE COMPONENTS AND THEIR GEOLOGICAL IMPLICATION IN THE INNER SHELF OF THE EAST CHINA SEA |
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TIAN Yuan1, FAN De-Jiang1, ZHANG Xi-Lin2, CHEN Bin2, WANG Liang3, PANG Yue1
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1.College of Marine Geosciences, Ocean University of China, Qingdao 266100, China;2.Qingdao Institute of Marine Geology, Ministry of Land and Resources, Qingdao 266071, China;3.Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China
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| Abstract: |
| Sediment grain size contains rich information about sedimentary environment and thereby is often used as a proxy to reconstruct the paleo-environment. We performed grain size analysis on three cores taken in the inner shelf of the East China Sea. Sensitive grain size components were analyzed, and their geological implication discussed. Three sensitive grain size components were recognized at <12μm (Component 1), 12-225μm (Component 2), and >225μm (Component 3), respectively. The overall grain size showed a fining-up trend from north to the south on the inner shelf. Component 1 and 2 were believed as being formed in homogenous suspension and graded suspension transportation, respectively, and Component 3 was very likely resulted from biological processes. Depending on characteristics of the regional ocean current system, Component 2 is more suitable as a proxy to indicate the winter ocean hydrodynamic strength, and thus the intensity of Winter East Asian Monsoon. |
| Key words: inner shelf of East China Sea sensitive grain-size component transportation mechanism environmental proxy |
