南海东北部晚更新世以来沉积环境演变的矿物-地球化学记录

杨群慧; 张富元; 林振宏; 周怀阳

南海东北部晚更新世以来沉积环境演变的矿物-地球化学记录

1.
中国科学院, 广州地球化学研究所, 广东, 广州, 510640
2.
国家海洋局海底科学重点实验室, 浙江, 杭州, 310012
3.
中国海洋大学, 山东, 青岛, 266003

基金项目: 国家重点基础研究发展规划资助项目(G200007850);中国科学院广州地球化学研究所知识创新工程领域前沿资助项目(GIGCX-03-07)

计量
- 文章访问数: 753
- HTML全文浏览量: 6
- PDF下载量: 1137
- 被引次数: 0
出版历程
- 收稿日期: 2002-08-25
- 修回日期: 2003-06-02

On mineralogical and geochemical records of paleosedimentary environmental variation in the northeastern South China Sea since the late Pleistocene

1.
Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
2.
Key Laboratory of Submarine Geosciences of State Oceanic Administration, Hangzhou 310012, China
3.
Ocean University of China, Qingdao 266003, China

摘要

摘要: 对南海东北部69柱(20°07.10'N,118°49.0'E)沉积物岩心进行碎屑矿物-地球化学特征研究,结果表明,以孔深165cm为界可划分出晚更新世末次冰期沉积和全新世冰后期沉积,这一地层划分结果与根据浮游有孔虫氧、碳同位素分析得出的结果是一致的.末次冰期时自生黄铁矿和硫元素高度富集,钠与铝、镁与铝和钠与钾的比值均较高,重矿物和SiO₂含量较高,CaCO₃含量较低,反映当时是一种相对闭塞的缺氧环境,气候干寒,化学风化作用较弱,以机械风化作用为主;研究区主要接受粒径较粗的硅质沉积;陆源物质的稀释作用可能是造成碳酸盐含量相对较低的主要原因.冰后期褐铁矿出现高含量,钠与铝、镁与铝和钠与钾的比值均降低,Al₂O₃和CaCO₃含量增高,反映沉积环境渐变为开放的氧化环境,气候转变为化学风化作用较强的湿热气候;研究区以接受较细粒的铝硅酸盐沉积为主,冰消期时还出现了碳酸盐保存高峰事件.
- 南海 /
- 矿物-地球化学记录 /
- 沉积环境
Abstract: Based on the clastic mineralogical and geochemical characteristics, it is indicated that the core 69 with a length of 560 cm (20°07.10"N, 118°49.0'E; 2 971 m water depth) sampled by gravity piston corer from the north-eastern South China Sea could be divided into the late Pleistocene last glacial period and the Holocene epoch with a boundary at about 165 cm.This result consists with that of the oxygen and carbon stable isotopic analyses of planktonic foraminifers.During the last glacial period, there was a relatively closed anoxic environment, dry and cold climate, weak chemical weathering conditions which were suggested by the characteristics of higher content of heavy mineral with abundant authigenic pyrite, higher SiO₂ and S contents, and lower CaCO₃ content, as well as higher ratios of Na to Al, Mg to Al and Na to K in sedimentary samples.The sediments are composed mainly of siliceous deposits.The lower CaCO₃ contents of sediments might caused by the dilution of terrigenous components.In turn, during the postglacial period, the CaCO₃ and Al₂O₃ contents became higher, and the ratios of Na to Al, Mg to Al and Na to K decreased, which reflected that the sedimentary environment became an open oxidation environment, the climate became humid and hot with a stronger condition of chemical weathering.The sediments are composed mainly of aluminosilicate deposits.Furthermore, the maximum carbonate content occurs in the deglaciation period.
- South China Sea /
- mineralogical and geochemical records /
- paleosedimentary environment.

HTML全文

参考文献(29)

金秉福,林振宏,杨群慧,等.沉积矿物学在陆缘海环境分析中的应用[J].海洋地质与第四纪地质,2002,22(3):113-118.

SCHAFER J, DORR W. Heavy mineral analysis and typology of detrital zircons: a new approach to provenance study(Saxothuringian Flysch, Germany)[J]. Journal of Sedimentary Research, 1997, 67(3): 451-461.

TAYLOR S R, McLENNAN S M. The Continental Crust: Its Composition and Evolution. An Examination of the Geochemical Record Preserved in SEDIMENTARY Rocks[M]. Oxford: Blackwell Scientific Publication, 1985. 301.

ROLLINSON H R. Using geochemical Data: Evaluation, Presentation, Interpretation[M]. New York: Longman Scientific, Technical, 1993, 352.

汪品先,等.十五万年来的南海[M].上海:同济大学出版社,1995.184.

WANG Lue-jiang, SARNTHEIN M, ERLENKEUSER H, et al. East Asian monsoon climate during the late Pleistocene:high-resolution sediment records from the South China Sea[J]. Marine Geology, 1999, 156: 245-284.

冯文科,薛万俊,杨达源.南海北部晚第四纪地质环境[M].广州:广东科学技术出版社,1988.156-162.

冯文科,杨达源.南海北部大陆坡-深海平原晚更新世以来的沉积特征与环境变化[J].中国科学(B辑),1988,11:1 215-1 225.

陈木宏,涂霞,郑范,等.南海南部近20万年沉积序列与古气候变化关系[J].科学通报,2000,45(5):542-548.

苏广庆王有强.南沙群岛海区晚第四纪碳酸盐沉积[J].台湾海峡.1994,13(3):263-274.

苏广庆,王天行.南海中北部表层沉积物的矿物沉积[J].台湾海峡,1992,11(2):118-124.

桂训唐,于津生,李献华,等.南沙海域沉积物Sr-O同位素组成与古环境[J].科学通报,1993,38(19):1 786-1 790

张明书,刘健,周墨清.西琛一井礁序列锶同位素组分变化[J].海洋地质与第四纪地质,1995,15(1):125-130.

韦刚健,桂训唐,李献华,等.南沙NS90-103钻孔沉积物Sr-Nd同位素组成及其气候环境信息探讨[J].中国科学,2000,30(3):249-255.

韦刚健,李献华,陈毓蔚,等.NS93-5钻孔沉积物高分辨率过渡金属元素变化及其古海洋记录[J].地球化学,2001,30(5):450-458.

邵磊,李献华,韦刚健,等.南海陆坡高速堆积体的物质来源[J].中国科学,2001,31(10):828-833.

颜文,陈忠,王有强,等.南海NS93-5柱样的矿物学特征及矿物沉积序列[J].矿物学报,2000,20(2):143-149.

颜文,古森昌,陈忠,等.南海97-37柱样的主元素特征及其潜在的古环境指示作用[J].热带海洋学报,2002,21(2):75-83.

张富元,章伟艳,杨群慧.南海东部海域沉积物粒度分布特征[J].沉积学报,2003,21(3):452-460.

QONATTI E, FISHER D E, JOENSUU O, et al. Postdepositional mobility of some transition elements, phosphorus uranium and thorium in deep sea sediments[J]. Geochim Cosmochim Acta, 1971, 35: 189-201.

初凤友,陈丽蓉,申顺喜,等.南黄海自生黄铁矿成因及其环境指示意义[J].海洋与湖沼,1995,26(3):227-233.

孙湘君,李逊,罗运利.南海北部深海花粉记录的环境演变[J].第四纪研究,1999,1:18-26.

孙湘君,李逊,陈怀成.南海北部最近37 ka以来的天然火与气候[J].中国科学(D辑),2000,30(2):163-168.

SAWYER E W. The influence of source rock type, chemical weathering and sorting on the geochemistry of clastic sediments from the Quetico metasedimentary belt, Superior Province, Canada[J]. Chemical Geology, 1986, 55: 77-95.

杨守业,李从先长江与黄河现代表层沉积物元素组成及其示踪作用[J].自然科学进展,1999,9(10):930-937.

WANG Pin-xian, WANG Lue-jiang, BIAN Yun-hua, et al. Late Quaternary paleoceanography of the South China Sea:surface circulation and carbonate cycles[J]. Marine Geology, 1995, 127:145-165.

汪品先.西太平洋边缘海的冰期碳酸盐旋回[J].海洋地质与第四纪地质,1998,18(1):1-11.

BERGER W H. Pacific carbonate cycles revisited: arguments for and against productivity control[A]. ISHIZAKI K,SAITO T. Centenary of Japanese Micropaleontology[M]. Tokyo Terra: Scientific Publ Co, 1992. 15-25.

魏国彦,李孟扬,段威武,等.南海东北部末次冰期一全新世古海洋学[J].海洋地质与第四纪地质,1999,19(3):19-27.

施引文献

资源附件(0)

访问统计