极地研究

极地研究

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白令海深海异常沉积特征及成因分析

黄元辉1 石学法1 葛淑兰1 刘焱光1 陈志华1王旭晨2 吕华华1   

  1. 1国家海洋局 第一海洋研究所 海洋沉积与环境地质国家海洋局重点实验室，山东 青岛 266061;  ２中国海洋大学，海洋化学理论与技术教育部重点实验室，山东青岛266100
  • 出版日期:2014-03-30 发布日期:2014-03-30

CHARACTERISTICS OF  ABNORMAL DEEP-SEA SEDIMENTS IN THE BERING SEA AND RHEIR POSSIBLE CAUSES

Huang Yuanhui1, Shi Xuefa1, Ge Shulan1, Liu Yanguang1, Chen Zhihua1, Wang Xuchen2, Lv Huahua1   

  1. 1Key Laboratory of State Oceanic Administration for Marine Sedimentology & Environmental Geology, First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China；2 Key Laboratory of Marine Chemistry Theory and Technologhy, Ocean University of China, Qingdao 266100, China
  • Online:2014-03-30 Published:2014-03-30

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1254

被引次数

3

摘要： 利用我国历次北极科学考察航次在白令海北部陆坡及海盆等深水区所采沉积物样品，对其开展沉积学等研究，系统归纳该海域常见的异常沉积类型及特征，并初步探讨其可能成因。BR02孔出现至少3段浊积层，浊积层主要分布于末次冰消期至中全新世。B5-4孔存在至少2段火山碎屑沉积层，其沉积年代分别约为1.3 kaBP和13.2 kaBP。B5-7站表层沉积物中的硅藻组合以新近系硅藻化石Kisseleviella carina Sheshukova-Poretzkaya和Kisseleviella ezoensis Akib为主，且与附近海域其它表层沉积物的硅藻组合面貌差异明显，可能是沉积物再沉积结果，其初始沉积年代大约为早中新世。白令海北部陆缘/陆坡区附近遍布的海底大峡谷对该区沉积物沉积过程具有重要影响，可能是导致该区浊流沉积与再沉积物的主要原因。此外，白令海位于欧亚板块、太平洋板块及北美板块交汇区边缘，其独特的地理位置决定该区地震与火山等构造活动相对活跃，进而进一步促使该区海底异常沉积现象频发。

关键词: 白令海, 异常沉积, 浊流, 火山碎屑, 再沉积

Abstract: Sediment samples from the previous China Arctic Expeditions in the north continental slope and deep basin of Bering Sea were used for sedimentology studies. Abnormal sedimentary types and their characteristics were summarized, and the possible causes were preliminarily discussed. At least three turbidite layers appear in core BR02, which distributing mainly from the last deglacial to Mid-Holocene. More than two volcano clastic sedimentary layers were affirmed in Core B5-4, which formed at ca. 1.3 kaBP and 13.2 kaBP respectively. Diatom assemblage of surface sediment of Core B5-7 is dominated by Neogene fossil diatoms of Kisseleviella carina Sheshukova-Poretzkaya and Kisseleviella ezoensis Akib, which is distinctively different from that of other adjacent surface sediments. We presume it could be the result of reworking and its initial depositional age could be about the early Miocene. The numerous submarine canyons incising the continental margin of the Bering Sea may exert great impact on sedimentation processes, which could be the main reason of kinds of abnormal sedimentation processes around this sea area. Moreover, the special locality of Bering Sea along the margin between the Eurasian plate and the North American plate is also decisive for it frequently suffering from earthquakes and volcanic activities, which in turn promote submarine abnormal sedimentation processes to occur more frequently.

Key words: Bering Sea, abnormal sedimentation process, turbidity, tephra, reworked sediment