放射性同位素定年技术在崇明岛潮滩沉积速率上的应用研究
Application of Radioisotope Geochronology in Study on Sedimentation Rate of Tidal Flat of Chongming Island
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摘要: 选取崇明岛北侧由东至西4个潮滩沉积柱,分析137Cs、226Ra和210Pb放射性比活度,应用210Pb和137Cs放射性同位素定年方法计算崇明岛潮滩沉积物沉积速率。对于东西两端,210Pb方法测得速率分别为3.08 cm/a和2.34 cm/a,而137Cs测得速率分别为6.19 cm/a和2.06 cm/a。结果表明,137Cs定年方法计算出的潮滩沉积速率普遍大于210Pb方法结果,但两者反映了相同的速率规律。崇明岛主力生长方向为东和东北,西侧沉积作用相对较弱,表现出"东快西慢"的特点。沉积纵向上,1954年以来,自下而上沉积速率逐渐减缓。Abstract: Four tidal flat sediment cores were collected from east to west along the northern shore of Chongming Island and specific activities of 137Cs, 226Ra and 210Pb were determined. The sedimentation rates of the Chongming Island mudflats were calculated by means of 210Pb and 137Cs geochronology. For the east and west ends of the northern mudflats, the sedimentation rates by 210Pb geochronology were 3.08 cm/a and 2.34 cm/a respectively, while the sedimentation rates by 137Cs geochronology were 6.19 cm/a and 2.06 cm/a respectively. Although the sedimentation rates calculated by 137Cs are generally higher than those from 210Pb, the same feature of sedimentation rates, viz "faster in the east, slower in the west" was indicated. And vertically the sedimentation rates were gradually slowdown from the bottom to the top since 1954.
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Keywords:
- 210Pb /
- 137Cs /
- radioisotope /
- geochronology /
- sedimentation /
- rate
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陈吉余,恽才兴,徐海根,董永发.两千年来长江口发育的模式[J].地理学报,1979,1(1) :103-111. 李伯昌.1984年以来长江口北支演变分析[J].水利水运工程学报,2006,9(3): 9-17. 贾海林,刘苍字,杨欧.长江口北支沉积动力环境分析[J].华东师范大学学报:自然科学版,2001(1):90-96. 杨欧,刘苍字.长江口北支沉积物粒径趋势及泥沙来源研究[J].水利学报,2002(2) :79-84. 吉云松,刘苍字,洪雪晴,孙艳梅.长江口北支中全新世以来的两次环境变异[J].海洋地质动态,2003,19(3) :125. 贾海林,刘苍字,张卫国,孟翊,洪雪晴.崇明岛CY孔沉积物的磁性特征及其环境意义[J].沉积学报,2004,22(1) :117-122. 李从先,王平,范代读,李铁松.潮汐沉积率与沉积间断[J].海洋地质与第四纪地质,1999,19( 2 ): 11-18. DeMaster D J,Mckee B A,Nittrouer C A,Qian Jiangchu, Cheng Guodong. Rates of sediment accumulation and particle reworking based on radiochemical measurements from continental shelf deposits in the East China Sea[J].Continental Shelf Research,1985,4(1-2) : 143-158. DeMaster D J,Mckee B A,Nittrouer C A,Qian Jiangchu, Cheng Guodong. Rates of sediment accumulation and particle reworking based on radiochemical measurements from continental shelf deposits in the East China Sea[J].Continental Shelf Research,1985,4(1-2) : 143-158.
刘国贤,杨松林,周义华.用210Pb法测定长江口沉积速率[J].海洋地质与第四纪地质,1984,4(1) :113-116. 段凌云,王张华,李茂田,潘建明,陈中原,Yishiki Saito, Yutaka kanai.长江口沉积物210Pb分布及沉积环境解释[J].沉积学报,2005,23(3):514-522. Goldberg E D.Geochronology with 210Pb //Radioactivity Dating.Vienna: International Atomic Energy Agency,1963: 121-131. Goldberg E D.Geochronology with 210Pb //Radioactivity Dating.Vienna: International Atomic Energy Agency,1963: 121-131.
钱江初,DeMaster D J,Nittrouer C A,Mckee B A.长江口邻近陆架210Pb的地球化学特征[J].沉积学报,1985,3(4): 31-42. Minoru Koide,Andrew Soutar,Edward D Goldberg. Marine geochronology with 210Pb [J].Earth and Planetary Science Letters,1972,14: 442-446. Minoru Koide,Andrew Soutar,Edward D Goldberg. Marine geochronology with 210Pb [J].Earth and Planetary Science Letters,1972,14: 442-446.
Pfitzner J,Brunskili G, Zagorskis I.137Cs and excess 210Pb deposition patterns in estuarine and marine sediment in the central region of the Great Barrier Reef Lagoon,northeastern Australia [J].Journal of Environmental Radioactivity,2004,76:81-102. Pfitzner J,Brunskili G, Zagorskis I.137Cs and excess 210Pb deposition patterns in estuarine and marine sediment in the central region of the Great Barrier Reef Lagoon,northeastern Australia [J].Journal of Environmental Radioactivity,2004,76:81-102.
康兴伦,袁毅,李培泉,纪正训,林炳兴,吴辉,刘书田.210Pb法在测定沉积速率中的应用[J].海洋科学,1985,9(1):38-42. 钱江初.210Pb测定沉积速率的误差及校正[J].东海海洋,1987,5(3):29-34. 夏小明,杨辉,李炎,李伯根,潘少明.长江口-杭州湾毗连海区的现代沉积速率[J].沉积学报,2004,22(1): 130-135. 何小勤,戴雪荣,刘清玉,李良杰,顾成军.长江口崇明东滩现代地貌过程实地观测与分析[J].海洋地质与第四纪地质,2004,24(2):23-27. 杨萌,陈中原,王张华.长江口崇明岛滩地重金属元素分布探讨[J].上海地质,2002(1):19-23.
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