热带海洋学报 ›› 2017, Vol. 36 ›› Issue (6): 27-38.doi: 10.11978/2017012

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海沟沉积物研究进展

肖春晖1(), 王永红1(), 林间2,3   

  1. 1. 海底科学与探测技术教育部重点实验室, 中国海洋大学海洋地球科学学院, 山东 青岛266100
    2. 美国伍兹霍尔海洋研究所, 马萨诸塞 伍兹霍尔02543
    3. 中国科学院南海海洋研究所, 广东 广州510301
  • 收稿日期:2017-01-23 修回日期:2017-08-14 出版日期:2017-11-30 发布日期:2018-01-18
  • 作者简介:

    作者简介:肖春晖(1991#cod#x02014;), 女, 山东省东营市人, 博士研究生, 海洋沉积学。E-mail: chunhuixiao@qq.com

  • 基金资助:
    国家重点研发计划项目(2016YFC0402602);国家自然科学基金(41376054、41176039、41410304022、91628301、U1606401);国家海洋局公益性项目(201405037);中国科学院项目(QYZDY-SSW-DQC005、Y4SL021001)

Research progress on ocean trench sedimentation

Chunhui XIAO1(), Yonghong WANG1(), Jian LIN2,3   

  1. 1. Key Lab of Submarine Geosciences and Prospecting Techniques, MOE and College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
    2. Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
    3. South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
  • Received:2017-01-23 Revised:2017-08-14 Online:2017-11-30 Published:2018-01-18
  • About author:

    Author:QIU Chunhua.E-mail: qiuchh3@mail. sysu.edu.cn

  • Supported by:
    National Key Research and Development Plan (2016YFC0402602);National Natural Science Foundation of China (41376054, 41176039, 41410304022, 91628301, U1606401);Public Welfare Project of the State Oceanic Administration (201405037);Chinese Academy of Sciences Project (QYZDY-SSW-DQC005, Y4SL021001)

摘要:

俯冲的大洋板块在自身的重力以及上覆板块的挤压下, 下潜时牵引洋底向下倾伏, 从而形成了深邃的海沟。板块及其所携带的沉积物在这里俯冲到地幔深处, 构成了全球物质循环的重要部分。海沟地处极端环境, 海沟沉积物的沉积作用不同于陆架和浅海地区, 其物源和水动力基本控制了沉积模式, 但海沟沉积物的物源、沉积环境和沉积机理则更为复杂。海沟沉积物受控于各种类型的构造运动, 包括由上覆板块刮削下来的深海沉积物和洋壳碎片堆积而成的沉积增生楔; 由海沟重力滑塌、地震等因素引发的浊流沉积; 以及由火山活动带来的火山物质等。同时, 海沟沉积物也受控于海沟逐渐形成过程中和形成后的各种沉积作用, 例如生物化学沉积和漏斗效应。由于海沟沉积物的沉积过程受到漏斗效应的影响, 使得海沟沉积一般比深海盆地堆积速度更快, 堆积厚度也更大, 但在海沟的不同位置或不同海沟之间, 堆积厚度也会有所不同。海沟的这些沉积机理和沉积过程的差异, 影响了海沟沉积物的性质, 包括沉积物粒度、矿物、生物等都有所差异。文章根据海沟以上的沉积特点, 分析了不同海沟之间和同一海沟内部海沟沉积厚度以及沉积物的粒度特征、矿物组成和生物特征的差异, 并总结了海沟重力滑塌、浊流沉积、火山活动、生物化学沉积、漏斗效应这五种海沟沉积机理对海沟沉积物沉积过程的影响。文章最后展望了海沟沉积物的研究热点, 希望在此基础上促进海沟沉积物的进一步研究。

关键词: 海沟, 沉积物, 物源, 沉积厚度, 沉积机理, 研究进展

Abstract:

Under its own gravitational weight and interaction with the overriding plate, a subducting oceanic plate bends significantly, leading to the formation of a deep trench. Here the subducted plate brings sediments into the mantle depths, constituting an important part of the global cycling of Earth materials. At the extreme environment of the deep ocean trench, the sedimentation processes differ significantly from that in a continental shelf or a shallow water zone. In general, the sediment provenances, environments, and mechanisms are much more complex at ocean trenches. Sediment sources at trenches are linked strongly to trench tectonics including, for example, the formation of accretionary wedges composing of deep sea sediments scraped off the overriding plate; turbidity deposits triggered by trench gravity sliding and seismic events; and volcanic deposits. Meanwhile, trench sediment is also controlled by other sedimentation mechanisms, including biochemical sedimentation and funneling effect. As a result of the funneling effect, trench sediment deposition rate is typically faster and thus thickness is greater than that at abyssal basins. Trench sediment thickness, however, varies significantly both within a trench and between trenches. The differences in the sedimentation mechanism and process affect the properties of trench sediments, including sediment grain-size, mineralogy, and biology. This paper examined intra- and inter-trenches variations in sediment thickness, grain-size, mineral composition, and biological characteristics. Several trench sedimentation mechanisms were examined, including gravity sliding, seismically-induced turbidity deposit, volcanic activity, biochemical sedimentation, and funneling effect. We also discussed the current research focuses in trench sedimentation research and the outlook of future investigations.

Key words: trench, sediment, sediment provenance, sedimentary thickness, sedimentary mechanisms, research progress and outlook

中图分类号: 

  • P736.2