综述与评述

喜马拉雅河流Sr同位素异常源岩研究现状及研究进展

  • 沈敢富 ,
  • 秦建华 ,
  • 冉敬 ,
  • 杜谷
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  • 1.成都地质矿产研究所,四川 成都 610082;2. 成都理工大学,四川 成都 610059
秦建华(1964-),男,四川成都人,研究员,主要从事沉积学和河流地球化学研究.E-mail:cdqjianhua@cgs.gov.cn

收稿日期: 2005-03-10

  修回日期: 2005-09-29

  网络出版日期: 2006-03-15

基金资助

国家自然科学基金项目“恒河—布拉马普特拉河Sr同位素异常源岩追踪”(编号:40273003);中国科学院广州地球化学研究所元素和同位素地球化学实验室资助.

The Current Situation and Advance of Research on the Source Rock for the Strontium Isotope in the Himalayan Rivers

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  • 1.Chengdu Institute of Geology and Mineral Resources, Chengdu 610082,China;2.Chengdu University of Technology, Chengdu  610059,China

Received date: 2005-03-10

  Revised date: 2005-09-29

  Online published: 2006-03-15

摘要

海洋Sr同位素的变化主要是由陆地河流注入的Sr同位素的变化所引起。在全球河流中,流经喜马拉雅山地河流(恒河—布拉马普特拉河)表现出与世界上其它河流明显不同的特点,具有高 87Sr/86Sr、高[Sr]的特征。恒河—布拉马普特拉河是世界上第四大河流,是当今世界海洋Sr的重要来源。国际上,目前人们对造成喜马拉雅河流Sr异常的原因(来源)的认识,仍存较大分歧。归纳起来,主要有3种认识:一是认为来源于硅酸盐岩;二是认为来源于碳酸盐岩的风化;三是认为来源于碳酸盐岩和硅酸盐岩的风化。近年来,作者对高喜马拉雅中央结晶岩系河流Sr同位素异常及其源岩进行的研究表明,高喜马拉雅河流Sr同位素受流域地质作用的强烈影响,呈现出高 87Sr/86Sr、低[Sr]的特点。对岩石和单矿物的研究表明,中央结晶岩系变质岩(片岩、片麻岩)和花岗岩黑云母中的 87Sr/86Sr与[Rb]成正比并具有高 87Sr/86Sr、低[Sr]的特征。黑云母矿物具有的易风化性,为高喜马拉雅河流放射性87Sr提供了主要来源。恒河—布拉马普特拉河的Sr异常(高 87Sr/86SrSr和高[Sr])则可能是反映了流经整个喜马拉雅造山带河流Sr混合平衡后的特征。

本文引用格式

沈敢富 , 秦建华 , 冉敬 , 杜谷 . 喜马拉雅河流Sr同位素异常源岩研究现状及研究进展[J]. 地球科学进展, 2006 , 21(03) : 262 -268 . DOI: 10.11867/j.issn.1001-8166.2006.03.0262

Abstract

The variation of the marine Sr isotope is largely caused with the input of the river Sr isotope. In the global rivers, the rivers draining through the Himalayan (Ganga-Brahmaputra rivers) possess the typical Sr isotope character, i.e. high  87Sr/86Sr ratio and high [Sr] concentration, which obviously differentiates from other rivers. The Ganga- Brahmaputra, the fourth largest river in the world, is important source for the marine Sr. Currently, it is still controversial for the source rock resulting in the Sr isotope anomaly in the Ganga Brahmaputra rivers. Basically, there appear three opinions for the source rock, the first opinion advocates that the source rock is the silicate rock, the second the carbonate, and the third both the silicate and carbonate. In the recent years, our research has disclosed that the Sr in the High Himalayan rivers possesses the feature of the high  87Sr/86Sr ratio and low [Sr] concentration, which is intensely affected by the specific geology in the drainage. The study on the metamorphic rocks ( schist, gneiss ) and the granites and the minerals indicates that in the biotite in the Central Crystal Series, the  87Sr/86Sr has the positive relationship with [Rb], and that the biotite also has the high  87Sr/86Sr ratio and low [Sr] concentration. The biotite is readily weathered and should  be the primary source to the radioactive 87Sr of the High Himalayan rivers. The Sr anomaly (high 87Sr/86Sr ratio and high [Sr]) in the Ganga- Brahmaputra is possibly attributed to the mixing balance of the rivers draining through the whole Himalayan.

参考文献

[1] Raymo M E, Ruddiman W F, Froelich P N. Influence of the late Cenozoic moutain building on ocean geochemical cycles[J]. Geology,1988,16: 649-653.

[2] Quade J, English N, Decelles P G. Silicate versus carbonate weathering in the Himalaya: A comparison of the Arun and Seti River watersheds[J]. Chemical Geology,2003,202: 275-296.

[3] Raymo M E, Ruddiman W F. Tectonic forcing of the Cenozoic climate[J]. Nature,1992,359: 117-124.

[4] Edmond J M. Himalayan tectonics, weathering processes ,and the strontium isotope record in marine limestones[J]. Science,1992,258: 1 594-1 597.

[5] Burke W H, Denison R E, Heatherington E A, et al. Variation of seawater 87Sr/ 86Sr throughout Phanerozoic time[J]. Geology,1982,10: 516-519.

[6] Wickman F E. Isotope ratios, a clue to the age of certain marine sediments[J]. The Journal of Geology, 1948, 56: 61-66.

[7] Ruddiman W F, Kutzbach J E. Forcing of the late Cenozoic Northern hemisphere climate by plateau uplift in Southern Asia and the American West[J]. Journal of Geophysical Research,1997,94:8 407-8 427.

[8] Richerter F M, Rowley D B, Depolo D J. Sr isotope evolution of seawater: The role of tectonics[J]. Earth Planetary Science of Letters,1992, 109:11-23.

[9] Qin Jianhua, Pan Guitang, Du Gu, et al. The progress for study on the change of Cenozic global climate, continental silicate rock weathering and marine strontium isotope[J]. Journal of Mineralogy and Petrology,2002,22(3): 31-35.[秦建华,潘桂棠,杜谷,. 新生代气候变化与陆地硅酸盐岩和海洋Sr 同位素研究[J].矿物岩石,2000,22(3):31-35.]

[10] Qin Jianhua, Pan Guitang, Du Gu. The effects of Cenozoic tectonic uplift on earth surface chemical weathering and global climate change[J]. Earth Science Frontiers, 2000,7(2): 517-525.[秦建华,潘桂棠,杜谷.新生代构造抬生对地表化学风化和全球气候变化的影响[J].地学前缘,2000,7(2):517-525.]

[11] Ruddiman W F, Prell W L. Introductin to the uplift—climate connection[C]Tectonic Uplift and Climate Change.Plenum,1997:3-14.

[12] McCauley S E, DePaolo J D. The marine 87Sr/86Sr and δ18O records, Himalayan alkalinity fluxes and Cenozoic climate models[C]Ruddimen W F, ed. Tectonic Uplift and Climate Change. Plenum,1997:428-465.

[13] Singh S K, Trivedi J R, Pande K, et al. Chemical and strontium, oxygen, and carbon isotopic compositions of carbonates from Lesser Himalaya: Implications to the strontium isotope composition of the source waters of the Ganga, Ghaghara, and the Indus rivers[J]. Geochimica et Cosmochimica Acta,1998,62: 743-755.

[14] Edmond J M, Huh Y. Chemical weathering yields from basement and orogenic terrains in hot and cold climates[C]Ruddiman W F, ed. Tectonic Uplift and Climate Change. Plenum,1997:329-351.

[15] Chen Jun, Yang Jiedong, Li Chunlei. The continental weathering and the global climatic change[J]. Advances in Earth Science, 2001, 16(3):399-405.[陈骏,杨杰东,李春雷.大陆风化与全球气候变化[J]. 地球科学进展, 2001, 16(3): 399-405.]

[16] Palmer M R, Edmond J M. Controls over the strontium isotope composition of river water[J]. Geochimica et Cosmochimica Acta, 1992, 56:2 099-2 111.

[17] Palmer M R, Edmond J M. The strontium isotope budget of the modern ocean[J]. Earth Planetary Science of Letters, 1989, 92:11-26.

[18] Huh Edmond. On the interpretation of the oceanic variations in 87Sr/86Sr as recorded in the marine limestones Proceeding[J]. Earth Planetary Science of Letters(Indian Academie Science),1998,107(4):293-305.

[19] Krishnaswami S, Trivedi J R, Sarin M M, et al. Strontium isotopes and rubidium in Ganga-Brahmaputra river system: Weathering in Himalaya, fluxes to the bay of Bengal and contributions to the evolution of oceanic 87Sr/ 86Sr[J]. Earth Planetary Science of Letters,1992,109:243-253.

[20] Galy A, France-Lanord C, Derry L A. The strontium isotopic budget of Himalayan rivers in Nepal and Bangladesh [J]. Geochimica et Cosmochimica Acta,1999, 63:1 905-1 925.

[21] Trivedi J R, Pande K, Krishnaswami S, et al. Sr isotope in rivers of India and Pakistan: A reconnaissance study[J]. Current Science,1995,69(2): 171-178.

[22] Pande K, Sarin M M, Trivedi J R, et al. The Indus River system (India-Pakistan): Major-ion chemistry, Uranium and strontium isotopes[J]. Chemical Geology, 1994,116: 245-259.

[23] Harris N B W. Significance of weathering Himalayan metasedimentary rocks and leucograsnites for the Sr isotope evolution of seawater during the early Miocene[J]. Geology,1995,23:795-798.

[24] Quade J, Roe L, Decelles P G, et al. The late Neogene 87Sr/86Sr record of lowland Himalayan rivers[J]. Science, 1997, 276: 1 828-1 831.

[25] Harris N, Bickle M, Chapman H, et al. The significance of Himalayan rivers for silicate weathering rates: Evidence from the Bhote Kosi tributary[J]. Chemical Geology,1998,144:205-220.

[26] Blum J D, Gazis C A, Jacobson A D, et al. Carbonate versus silicate weathering in the Raikhot watershed within the High Himalayan crystalline series[J]. Geology,1998,26:11-14.

[27] Blum J D. The effect of Late Cenozoic glaciation and tectonic uplift on silicate weathering rates and the marine 87Sr/86Sr record[C]Ruddiman W F, ed. Tectonic Uplift and Climate Change.Plenum,1997:260-286.

[28] LE Fort P. Metamorphism and magmatism during the Himalayan collision[C]Collision Tectonics. Geological Society of Special Publication,1986,19:159-172.

[29] Jacobson A D, Blum J D. Ca/Sr and 87Sr/86Sr geochemistry of disseminated calcite in Himalayan silicate rocks from Nanga Parbat: Influence on river-water chemistry[J]. Geology,2000, 28: 463-466.

[30] Bickle M J, Harris W, Bunbury N B, et al. Controls on the 87Sr/ 86Sr ratio of carbonates in the Garhwal Himalaya, Headwaters of the Ganges[J]. The Journal of Geology,2001,109: 737-753.

[31] English N B, Quade J, Decelles P G, et al. Geologic control of Sr and major element chemistry in Himalayan Rivers,Nepal[J]. Geochimica et Cosmochimica Acta,2000,64(13): 2 549-2 567.

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