北冰洋西部沉积物黏土的Sm-Nd同位素特征及物源指示意义

陈志华; 李朝新; 孟宪伟; 石学法; 程振波

北冰洋西部沉积物黏土的Sm-Nd同位素特征及物源指示意义

国家海洋局第一海洋研究所,山东青岛 266061;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

基金项目: 国家自然科学基金项目(41076136;40506004;40706030);中国第三次北极考察资助项目(CHINARE-2008);国家海洋局第一海洋研究所所长基金项目(2007T09)。

计量
- 文章访问数: 1945
- HTML全文浏览量: 37
- PDF下载量: 1500
- 被引次数: 0
出版历程
- 收稿日期: 2010-06-20

Samarium-neodymium isotopic characteristics of the clay-size fraction in surface sediments from the western Arctic Ocean and their implications for sediment sources and transport pattern

First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China;Key Laboratory of State Oceanic Administration for Marine Sedimentology & Environmental Geology, First Institute of Oceanogranhy, State Oceanic Administration Qingdao 266061, China

摘要

摘要: 通过对北冰洋西部(楚科奇海及北部边缘地带、加拿大海盆)34个表层沉积物样品中黏土组分的Sm-Nd同位素分析,结果表明:(1)黏土组分的Sm-Nd同位素分异明显,可将沉积物划分为北部、西部、南部和东部等多个同位素物源区;(2)在楚科奇海,太平洋入流的向北输运自西向东形成了3个不同的同位素物源区,沉积物的c(¹⁴⁷Sm)/c(¹⁴⁴Nd)比值、ε_Nd(0)值和T_DM年龄自西向东呈递减趋势;(3)在研究区北部,顺时针方向流动的波弗特涡流将马更些河物质向西搬运至加拿大海盆和楚科奇高地,使该区沉积物ε_Nd(0)值明显偏低,T_DM偏大;(4)在楚科奇海北部外陆架、海台和陆坡区,太平洋水、大西洋水和波弗特涡流的相互作用使该区沉积物T_DM年龄的标准偏差大,同时出现了南-北源和西-南源等同位素混合类型。
- 北冰洋西部 /
- 表层沉积物 /
- 黏土组分 /
- 杉-钕同位素 /
- 沉积物来源
Abstract: Sm-Nd isotopes were measured on the clay-size fraction of thirty-four surface sediments to clarify sediment provenance and transport mechanism in the western Arctic Ocean, the Chukchi Sea, the Chukchi Borderland and the Canadian Basin. Spatial variations of Sm and Nd isotopes of surface sediments indicate there are multiple provenances in the study area. In the Chukchi Sea, three isotope-inferred sediment provenances,which have gradually decreasing c(¹⁴⁷Sm) to c(¹⁴⁴Nd), epsilon values of Nd and model ages from west to east, indicate the northward transport paths of the three branches of the Pacific inflows. Due to the transport of the clockwise Beaufort Gyre, sediments are mainly derived from the Mackenzie River and have lower epsilon value Nd of (-13.28 -11.76) and older model age in the Canadian Basin and on the Chukchi Plateau in the north of the study area. Meanwhile, relatively larger model age deviations indicate there are strong water mass and sediment mixing due to co-actions of the Pacific water, the Atlantic water and the Beaufort Gyre on the Chuckchi Rise and continental slope.
- western Arctic Ocean /
- Samarium-neodymium isotopes /
- sediment provenance and transport mechanism /

HTML全文

参考文献(20)

OVERPECK J, HUGHEN K, HARDY D,et al. Arctic environmental change of the last four centuries[J]. Science,1997, 278: 1251—1256.

陈立奇. 南极和北极地区在全球变化中的作用研究[J]. 地学前缘, 2002, 9(2): 245—253.

杨伟锋, 陈敏, 刘广山, 等. 楚克奇海陆架沉积物中核素分布及其对沉积环境的示踪[J]. 自然科学进展, 2002, 12(5): 515—518.

高爱国, 刘焱光, 张道建,等. 楚科奇海与白令海表层沉积物中的碘的纬向分布[J]. 中国科学: D辑, 2003, 33(2):155—162.

陈志华, 石学法, 韩贻兵,等. 北冰洋西部表层沉积物黏土矿物分布及环境指示意义[J]. 海洋科学进展, 2004, 22(4):446—454.

陈志华, 石学法, 蔡德陵,等. 北冰洋西部沉积物有机碳、氮同位素特征及其环境指示意义[J]. 海洋学报, 2006, 28(6):61—71.

李宏亮, 陈建芳, 金海燕,等. 楚科奇海表层沉积物的生源组分及其对碳埋藏的指示意义[J]. 海洋学报,2007, 30(1): 165—171.

王汝建, 肖文申, 向霏,等. 北冰洋西部表层沉积物中生源组分及其古海洋学意义[J]. 海洋地质与第四纪地质, 2007, 27(6): 61—69.

杨杰东,徐士进.同位素与全球环境变化[M]. 北京:地质出版社, 2007: 141—147.

HORIKAWA K, ASAHARA1 Y, YAMAMOTO 1 K, et al. Intermediate water formation in the Bering Sea during glacial periods: evidence from neodymium isotope ratios[J]. Geology, 2010, 38(5): 435—438.

GOLDSTEIN S L, O'NIONS R K, HAMILTON P J. A Sm-Nd isotopic study of atmospheric dusts and particulates from major river systems[J]. Earth Planet Sci Lett, 1984, 70: 221—236.

GOLDSTEIN S J, JACOBSEN S B. Nd and Sr isotopic systematics of river water suspended material: implications for crustal evolution[J]. Earth and Planetary Science Letters,1988, 87: 249—265.

FRANK M. Radiogenic isotopes: tracers of past ocean circulation and erosional input[J]. Reviews of Geophysics, 2002, 40: 1001—1029.

Van LANINGHAM S, PISIAS N G.,DUNCAN R A, et al. Glacial-interglacial sediment transport to the Meiji Drift, northwest Pacific Ocean: evidence for timing of Beringian outwashing[J]. Earth and Planetary Science Letters, 2009, 277: 64—72.

WINTER B L, JOHSON C M, CLARK D L. Strontium, neodymium, and lead isotope variations of authigenic and silicate sediment components from the Late Cenozoic Arctic Ocean: Implications for sediment provenance and the source of trace metals in seawater[J]. Geochimica et Cosmochimica Acta, 1997, 61(19): 4181—4200.

WOLFGANG Schmitt. Application of the Sm-Nd Isotope system to the Late Quaternary paleoceanography of the Yermak Plateau (Arctic Ocean) . 2008-12-25:http:/edoc.ub.unimuenchen.de//1/schitt_wolfgang.pdf.

DAVIS W J, HEGNER E. Neodymium isotopic evidence for the tectonic assembly of Late Archean crust in the Slave Province, northwest Canada[J]. Contrib Mineral Petrol, 1992, 111: 493—504.

NELSON B K, NELSON S W, TILL A B. Neodymium and strontium isotope evidence for proterozoic and paleozoic crustal evolution in the Brooks Range, Northern Alaska[J]. J Geol, 1993, 101: 435—450.

JONES E P, ANDERSON L G, SWIFT J H. Distribution of Atlantic and Pacific waters in the upper Arctic Ocean: implications for circulation[J]. Geophys Res Lett, 1998, 25: 765—768.

赵进平, 史久新. 北极环极边界流研究及其主要科学问题[J]. 极地研究, 2004, 16(3): 159—169.

施引文献

资源附件(0)

访问统计