湖北三宝洞石笋<sup>238</sup>U值变化的古气候意义

董进国; 刁伟; 孔兴功

doi:10.3724/SP.J.1140.2013.01129

湖北三宝洞石笋²³⁸U值变化的古气候意义

1. 南通大学地理科学学院, 南通 226007;
2. 中国科学院地球环境研究所黄土与第四纪地质国家重点实验室, 西安 710075;
3. 南京师范大学地理科学学院, 南京 210046

基金项目:

黄土与第四纪地质国家重点实验室开放基金项目(SKLLQG1211)

国家自然科学基金项目(41102216)

详细信息

作者简介:
董进国(1978-),男,讲师,博士生,从事第四纪年代学与环境演变,E-mail:dongjinguo1111@163.com

中图分类号: P597
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- 文章访问数: 1944
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出版历程
- 收稿日期: 2012-09-18
- 修回日期: 2012-11-02

VARIATION IN URANIUM ISOTOPES OF STALAGMITES FROM SANBAO CAVE, HUBEI PROVINCE: IMPLICATIONS FOR PALAEOCLIMATE

1. College of Geography Science, Nantong University, Nantong 226007;
2. College of Geography Science, Nanjing Normal University, Nanjing 210097

摘要

摘要: 通过对湖北三宝洞17支石笋160个测年样品的铀同位素数据分析,发现过去18万年以来石笋²³⁸U值长尺度变化与其δ¹⁸O记录有一定的负相关关系,与西太平洋海表温度变化具有良好的正相关。石笋²³⁸U值在间冰期波动剧烈,而在冰期波动相对平缓,在冰期-间冰期转型时²³⁸U值"爆发式"增大。在轨道尺度上,高浓度²³⁸U对应于石笋平均生长速率的高值期,而低浓度值对应于生长速率的低值期。上述结果表明与外界气候变化相关的洞穴上覆土壤的成壤过程和岩溶水文变化可能是控制石笋²³⁸U含量变化的主要因素,石笋²³⁸U可以作为一个新的洞穴气候环境代用指标,但仍须谨慎对待。
- 石笋 /
- 铀含量 /
- 古气候代用指标 /
- 三宝洞
Abstract: A great number of oxygen isotope ratios and U-Th ages data were collected and studied by the authors for the stalagmites from the Sanbao cave, Hubei Province, China. Uranium-series dating of the speleothem suggests that the stalagmites are formed in the period from the penultimate glacial period up to the present. This paper deals with the relationship between uranium concentration in stalagmites and paleoclimate data induced from the 160 precise ICP-MS ²³⁰Th data collected from 17 stalagmites from the Sanbao Cave. We discovered that the variations in ²³⁸U show a negative relation with the δ¹⁸O records of the studied stalagmites, and a positive relation with the temperature changes in West Pacific Warm Pool. The concentration of ²³⁸U in the stalagmites fluctuated rapidly during the interglacial periods, slowly during the glacial periods, and increased sharply in the past two terminations. On the orbital scale, the higher the average growth rate, the higher the uranium concentration is, and vice versa. The results also show that the pedogenic processes of the soil profile above the cave and the complex soil-water-rock interaction are well related with the outer-cave climate changes, possibly responsible for the shifts of uranium concentration. However, the shift of the ²³⁴U/²³⁸U in stalagmites seems having no any relation with the external palaeoenvironment over the past 180000 years. Therefore, the uranium concentration in the stalagmite could only be used as a new proxy for climate change with caution.
- stalagmites /
- U concentration /
- palaeoclimate /
- Sanbao cave

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参考文献(26)

[1]	Hellstrom J C, McCulloch M T Multi-proxy constraints on the climatic significance of trace element records from a New Zealand speleothem[J].Earth and Planetary Science Letters,2000,179:287-297.
[2]	张德忠,张平中,桑文翠,等.石笋密度蕴含的过去气候变化信息:以末次冰消期黄土高原西部武都万象洞石笋为例[J].科学通报,2010,55(31):3040-3047. [ZHANG Dezhong,ZHANG Pingzhong,SANG Wencui,et al. Implications of stalagmite density for past climate change:An example from stalagmite growth during the last deglaciation from Wanxiang Cave, western Loess Plateau[J]. Chinese Science Bulletin,2010,55(34):3936-3943.]
[3]	张德忠,白益军,桑文翠,等.末次冰消期亚洲季风强度变化的黄土高原西部万象洞石笋灰度记录[J].第四纪研究,2011,31(5):791-799. [ZHANG Dezhong,BAI Yijun,SAN Wencui,et al. Asian monsoon intensity variations during the last deglaciation recorded by stalagmite gray scale from Wanxiang Cave,Western Loess Plateau[J].Quaternary Science,2011, 31(5):791-799.]
[4]	邵晓华,汪永进,孔兴功,等.南京葫芦洞石笋生长速率及其气候意义讨论[J].地理科学,2003,23(3):304-309. [SHAO Xiaohua, WANG Yongjin, KONG Xinggong,et al. Approach to the growth rate and the climatic significance of stalagmite in Hulu cave, Nanjing[J]. Science Geographica Sinica, 2003, 23(3):304-309.]
[5]	Kaufman A, Wasserburg G J, Porcelli D, et al. U-Th isotope systematics from the Soreq cave, Israel and climatic correlations[J]. Earth and Planetary Science Letters, 1998, 156:141-155.
[6]	况润元,汪永进,张向华,等.石笋铀同位素组成对土壤环境变化的指示[J].科学通报,2002,47(13):1022-1026. [KUANG Runyuan,WANG Yongjin,Zhang Xianghua,et al. Implications for soil environment from uranium isotopes of stalagmites[J]. Chinese Science Bulletin,2002,47(19):1653-1658.]
[7]	杨琰,袁道先,程海,等.洞穴石笋初始²³⁴U/²³⁸U值的古气候记录意义[J].地质学报,2008,82(5):692-701. [YANG Yan, YUAN Daoxian, CHENG Hai et al. Initial ²³⁴U/²³⁸U variation of stalamites:implications for paleoclimate reconstruction[J]. Acta Geologica Sinica, 2008,82(5):692-701.]
[8]	Zhou J, Lundstrom C C, Fouke B, et al. Geochemistry of speleothem records from southern Illinois:Development of (²³⁴U)/(²³⁸U) as a proxy for paleoprecipitation[J]. Chemical Geology, 2005, 221:1-20.
[9]	Shen C C, Edwards R L, Cheng H, et al. Uranium and thorium isotopic and concentration measurements by magnetic sector inductively coupled plasma mass spectrometry[J]. Chemical Geology,2002,185:165-178.
[10]	赵侃,孔兴功,程海,等.MIS3晚期东亚季风强度和DO事件年龄[J].第四纪研究,2008,28(1):177-183. [ZHAO Kan,WANG Yongjin,CHENG Hai,et al. Intensity and timing of D-O events East Asian monsoon during the late episode of MIS3[J]. Quaternary Science, 2011,28(1):177-183.]
[11]	Dong J G, Wang Y J, Cheng H, et al. A high-resolution stalagmite record of the Holocene East Asian monsoon from Mt Shennongjia,central China[J]. The Holocene, 2010, 20(2):257-264.
[12]	Wang Y J, Cheng H, Edwards R L, et al. Millennial-and orbital-scale changes in the east Asian monsoon over the past 224000 years[J].Nature, 2008, 451:1090-1093.
[13]	董进国,孔兴功,汪永进.神农架全新世东亚季风演化及其热带辐合带控制[J].第四纪研究,2006,26(5):826-834. [DONG Jinguo,KONG xinggong,WANG yongjin.The East Asian monsoon climate changes at MT. Shennongjia and its relation to shift of intertropical convergence zone during the Holocene[J]. Quaternary Sciences, 2006,26(5):826-834.]
[14]	Lea D W, Pak D K, Spero H J. Climate impact of Late Quaternary Equatorial Pacific sea surface temperature variations[J]. Science, 2000, 289:1719-1724.
[15]	Zhang P Z,Cheng H,Edwards R L,et al. A test of climate, sun, and culture relationships from an 1810-year Chinese cave record[J]. Science,2008,322:940-942.
[16]	Cai Y J,Tan L C,Cheng H,et al. The variation of summer monsoon precipitation in central China since the last deglaciation[J]. Earth and Planetary Science Letters,2010,291:21-31.
[17]	Cheng H, Edwards R L, Broecker W S, et al. Ice age terminations[J]. Science, 2009, 326:248-252.
[18]	刘东静.ICP-MS测定武汉水源水及饮用水中的铀[J].环境科学与技术,2010,33(6E):262-263. [LIU Dongjing. The analysis of uranium elements by ICP-MS[J]. Environmental Science and Technology, 2010,33(6E):262-263.]
[19]	郭志英,梁月琴,李娟,等.ICP-MS对我国9种典型土壤中铀含量及²³⁵U/²³⁸U比值的分析[J].中国辐射卫生,2011,20(1):30-32. [GUO Zhiying,LIANG Yuejuan,LI Juan,et al. Study of Uranium concentration and ²³⁵U/²³⁸U isotopic ratio in nine kinds of soils in China[J].Chinese Journal of Radiological Health,2011,20(1):30-32.]
[20]	牟保磊.元素地球化学[M].北京:北京大学出版社,1999:122-128.[MU, Baolei. Geochemistry of Elements[M]. Beijing:Peking University Publishing House,1999:122 -128.]
[21]	林瑞芬,卫克勤,王志祥.太原地区地下水铀含量和²³⁴U/²³⁸U比值研究[J].地球化学,1986,3:193-201.[LIN Ruifen,WEI Keqin,WANG Zhixiang.A study of ^{234 U/²³⁸U ratio in ground waters of Taiyuan area, Shanxi Province[J].Geochimica,1986,3:193-201.]}
[22]	曹丁涛.邵庄-双庙水源地不同水体U同位素组成特征的初步研究[J].中国岩溶,2007,26(4):347-355. [CAO Dingtao. Preliminary study on the component of Uranium isotopes in various water-bodies in Shaozhuang-Shuangmiao water source area[J].Carsologica Sinica,2007,26(4):347-355.]
[23]	董进国.湖北三宝洞石笋生长速率及其古气候意义[J].第四纪研究,2012,32(6):1-9. [DONG Jinguo. The growth and the paleoclimatic significance of stalagmites in Sanbao Cave, Hubei[J]. Quaternary Sciences, 2012, 32(6):1-9.]
[24]	宋照亮,刘丛强,韩贵琳,等.乌江流域沉积岩风化过程中铀的富集与释放[J].环境科学,2006,27(11):2273-2278. [SONG Zhaoliang,LIU Congqiang,HAN Guilin, et al. Enrichment and release of uranium during weathering of sedimentary rocks in Wujiang catchments[J]. Environmental Science,2006,27(11):2273-2278.]
[25]	程汝楠,尹金双.潮湿气候下天然水中铀的迁移形式和沉积富集条件的探讨[J].沉积学报,1985,3(1):42-53. [CHENG Runan,YIN Jinshuang.On migration from and sedimentary enrichments of uranium in natural water under wet climate in South China[J].Acta Sedimentolgica Sinica, 1985,3(1):42-53.]
[26]	Latham A G,Schwarz H P.On the possibility of determining rates of removal of uranium from crystalline igneous rocks using U-series disequilibria-1:A U-leach model and its applicability to whole-rock data[J].Applied Geochemistry,1987,2:55-65.