| 摘要: |
| 为探讨东海内陆架17.3ka BP 以来的重矿物含量变化及其物源指示意义, 对东海内陆架南 部泥质沉积中心EC2005 孔的沉积重矿物进行了鉴定和分析。结果表明: (1) 在0.063-0.25mm 粒级 沉积物中, 重矿物含量平均值为27.3%, 变化范围为3.7%-89.6%, 重矿物含量较高的部分均出现在 自生黄铁矿富集的层位; (2) 片状矿物、含铁氧化物、角闪石族矿物、绿帘石族矿物、白云石、辉石 族矿物、变质矿物、蚀变矿物和自生黄铁矿占重矿物颗粒总数的96.0%以上, 但其含量变化很大; (3) 以重矿物分布特征为依据将岩心划分为Ⅰ-Ⅴ五个沉积层段, 各层段对应的特征矿物分别为片状矿 物、白云石、片状矿物、自生黄铁矿和榍石。结合粒度、AMS14C 年代及西太平洋海平面变化等数 据对物源进行分析, 结果表明: 自17.3ka BP 以来, EC2005 孔沉积物源主要是长江, 其次还可能受到 瓯江等浙江沿岸河流所输运物质的一定影响。 |
| 关键词: 重矿物 物源 EC2005 孔 东海内陆架 |
| DOI：10.11693/hyhz20141100335 |
| 分类号: |
| 基金项目:国家自然科学重点基金项目, 41430965 号; 国家自然科学基金项目, 41106040 号, 41406064 号。 |
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| HEAVY MINERAL ASSEMBLAGES IN CORE EC2005 IN THE INNER SHELF OF EAST CHINA SEA AND THE ORIGIN |
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DONG Jiang1,2, LI An-Chun1, XU Fang-Jian2, HUANG Peng1, ZHANG Kai-Di1
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1.Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China;2.College of Earth Science and Technology, China University of Petroleum, Qingdao 266580, China
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| Abstract: |
| Heavy minerals in the bore hole EC2005, located in the southern center of mud area in the inner shelf of East China Sea, was identified and analyzed for their significance of provenances since 17.3ka BP. The results show that in the sediment of grain size 0.063-0.25mm, the average content of heavy minerals is 27.26% in range of 3.66%-89.62%. High content of heavy minerals appears in the horizon of rich authigenic pyrite. The heavy minerals included lamellar mineral, metallic mineral, amphibole, epidote, dolomite, pyroxene, typical metamorphic minerals, altered minerals and authigenic pyrite, and they altogether took more than 96.00% of the total amount, but varied in content through core EC2005 The distribution of heavy minerals can be divided into five units from the Unit Ⅰto Unit Ⅴ from bottom to top; the characteristic minerals are lamellar minerals, dolomite, lamellar minerals, authigenic pyrite, and titanite. In combination with AMS14C dating and the sea level data in the west Pacific Ocean, we analyzed the provenance of the sediment. Results show that, during 17.3-0ka BP, the place of the core received primarily from Changjiang (Yangtze) river, and also some from along-coast current off Zhejiang Province. |
| Key words: Heavy mineral provenance bore-hole EC2005 inner shelf of the East China Sea |
