摘要
距今4—3千年正值中华文明确立和发展的重要时期,这个时段的气候变化资料有利于深入理解环境与人类文明发展的相互关系。本研究利用辽宁本溪庙洞石笋MD11,通过~(230)Th定年和高分辨率氧同位素分析,重建了4.09—2.84 ka BP东北地区南部夏季风降水变化历史。4.09—3.85 ka BP时段,东亚夏季风较为稳定,期间在约3.95 ka BP前后出现短暂的夏季风小幅度减弱,与亚洲季风区石笋记录类似,推测4.2 ka事件应早于4.1 ka BP,支持早前南方石笋记录的结论;3.85—2.84 ka BP时段,庙洞石笋沉积速率显著降低,氧同位素整体偏正,说明这段时间内东亚季风总体偏弱,辽宁东部地区夏季风降水偏少,期间只在3.05 ka BP先后出现持续时间约为数十年的夏季风增强过程。
Much attention has been paid to the variability in East Asian Summer Monsoon(EASM)during the first few thousand years of late Holocene,due to its potential connection with Chinese civilization development. In this study,a stalagmite MD11 from the Miaodong cave,Benxi,Liaoning province has been employed to reconstruct a high resolution δ~(18)O record during time period between 4. 09 ka BP and 2. 84 ka BP. The variability in MD11 δ~(18)O is explained to be a proxy index of EASM and(or) local summer monsoon precipitation,with more negative value indicating stronger EASM or more summer precipitation. During 4. 09—3. 85 ka BP,the EASM was relatively stable,similar to some stalagmite records from southern China,indicating that the well known "4. 2 ka "cold event( failure EASM) maybe occurred at least earlier than 4. 1 ka BP. In general term,δ~(18)O value is much less negative from 3. 85 ka BP until 2. 84 ka BP. This observation is together with much lower deposition rate,revealing a long term weakening of EASM. It should be known that a short term( several decades) rebound in intensity of EASM occurred at around 3. 05 ka BP. Our observation coincides with that of history document that weak EASM and drought in northern China dominate the time period of 4—3ka BP.
引文
[1]吴文祥,刘东生.4 000 a BP前后降温事件与中华文明的诞生[J].第四纪研究,2001,21(5):443-451.
[2]王绍武,黄建斌.全新世中期的旱涝变化与中华古文明的进程[J].自然科学进展,2006,16(10):1238-1244.
[3]施雅风,孔昭宸,王苏民,等.中国全新世大暖期的气候波动与重要事件[J].中国科学:化学,1992,22(12):1300-1308.
[4]BOND G,BONANI G.A pervasive millennial-scale cycle in North Atlantic Holocene and glacial climates[J].Science,1997,278(7):2402-2415.
[5]BOND G,KROMER B,BEER J,et al.Persistent solar influence on North Atlantic climate during the Holocene[J].Science,2001,294(5549):2130-2136.
[6]安成绑,冯兆东,唐领余.黄土高原西部全新世中期湿润气候的证据[J].科学通报,2003,48(21):2280-2287.
[7]FENG Z D,AN C B,TANG L Y,et al.Stratigraphic evidence of a megahumid climate between 10 000 and 4 000 years BP in the western part of the Chinese Loess Plateau[J].Global&Planetary Change,2004,43(3):145-155.
[8]唐领余,安成邦.陇中黄土高原全新世植被变化及干旱事件的孢粉记录[J].自然科学进展,2007,17(10):1371-1382.
[9]王绍武,黄建斌,闻新宇,等.4~2 ka BP中国干旱的证据和模拟研究[J].科学通报,2007,52(20):2428-2433.
[10]WANG Y,CHENG H,EDWARDS R L,et al.The Holocene Asian monsoon:links to solar changes and North Atlantic climate[J].Science,2005,308(5723):854-857.
[11]HU C,HENDERSON G M,HUANG J,et al.Quantification of Holocene Asian monsoon rainfall from spatially separated cave records[J].Earth&Planetary Science Letters,2008,266(3-4):221-232.
[12]DYKOSKI C A,EDWARDS R L,CHENG H,et al.A high-resolution,absolute-dated Holocene and deglacial Asian monsoon record from Dongge Cave,China[J].Earth&Planetary Science Letters,2005,233(1-2):71-86.
[13]DONG J,WANG Y,CHENG H,et al.A high-resolution stalagmite record of the Holocene East Asian monsoon from Mt Shennongjia,central China[J].Holocene,2010,20(2):257-264.
[14]CAI Y,TAN L,CHENG H,et al.The variation of summer monsoon precipitation in central China since the last deglaciation[J].Earth&Planetary Science Letters,2010,291(1-4):21-31.
[15]吴文祥,刘东生.4 000 a BP前后东亚季风变迁与中原周围地区新石器文化的衰落[J].第四纪研究,2004,24(3):278-284.
[16]吴江滢,汪永进,董进国.全新世东亚夏季风演化的辽宁暖和洞石笋δ18O记录[J].第四纪研究,2011,31(6):990-998.
[17]王芳,孙青,蔡炳贵,等.辽宁本溪庙洞降水、滴水和现生碳酸钙的δ18O变化特征及其古气候意义[J].第四纪研究,2016,36(6):1370-1382.
[18]赵雷,吉奇,林双,等.1953—2012年桓仁县气温与蒸发量变化特征及趋势分析[J].现代农业科技,2015,(3):226-228.
[19]高博,吉奇,孙雪,等.近58年桓仁县暖干化趋势与土壤蒸发量特征分析[J].安徽农业科学,2014,(24):8289-8290.
[20]EDWARDS R L,CHEN J H,WASSERBURG G J.238U,234U,230Th,232Th systematics and the precise measurement of time over the past 500 000 years[J].Earth&Planetary Science Letters,1986,81(2-3):175-192.
[21]EDWARDS R L.High precision thorium-230 ages of corals and the timing of sea level fluctuations in the late Quaternary[D].Pasadena:California Institute of Technology,1988.
[22]CHENG H,EDWARDS R L,HOFF J,et al.The half-lives of uranium-234 and thorium-230[J].Chemical Geology,2000,169:17-33.
[23]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(3-4):165-178.
[24]HENDY C H.The isotopic geochemistry of speleothems:I.The calculation of the effects of different modes of formation on the isotopic composition of speleothems and their applicability as palaeoclimatic indicators[J].Geochimica et Cosmochimica Acta,1971,35(8):801-824.
[25]KIM S T,O'NEIL J R.Equilibrium and nonequilibrium oxygen isotope effects in synthetic carbonates[J].Geochimica et Cosmochimica Acta,1997,61(16):3461-3475.
[26]ARAGUAS-ARAGUAS L,FROEHLICH K,ROZANSKI K.Stable isotope composition of precipitation over southeast Asia[J].Journal of Geophysical Research Atmospheres,1998,1032(D22):28721-28742.
[27]谭明.环流效应:中国季风区石笋氧同位素短尺度变化的气候意义——古气候记录与现代气候研究的一次对话[J].第四纪研究,2009,29(5):851-862.
[28]YUAN D,CHENG H,EDWARDS R L,et al.Timing,duration,and transitions of the last interglacial Asian monsoon[J].Science,2004,304(5670):575-578.
[29]FLEITMANN D,BURNS S J,MUDELSEE M,et al.Holocene forcing of the Indian monsoon recorded in a stalagmite from southern Oman[J].Science,2003,300(5626):1737-1739.
[30]DUAN F,WANG Y,SHEN C C,et al.Evidence for solar cycles in a late Holocene speleothem record from Dongge Cave,China[J].Scientific Reports,2014,4(7503):182-182.
[31]STOTT L,CANNARIATO K,THUNELL R,et al.Decline of surface temperature and salinity in the western tropical Pacific Ocean in the Holocene epoch[J].Nature,2004,431(7004):56-59
[32]STAUBWASSER M,SIROCKO F,GROOTES P M,et al.Climate change at the 4.2 ka BP termination of the Indus valley civilization and Holocene south Asian monsoon variability[J].Geophysical Research Letters,2003,30(8):1425.
[33]ROLAND T P,CASELDINE C J,CHARMAN D J,et al.Was there a‘4.2ka event’in Great Britain and Ireland?Evidence from the peatland record[J].Quaternary Science Reviews,2014,83:11-27.
[34]LIU F,FENG Z.A dramatic climatic transition at~4 000 cal.yr BP and its cultural responses in Chinese cultural domains[J].Holocene,2012,22(10):1181-1197.
[35]XU D,LU H,CHU G,et al.500-year climate cycles stacking of recent centennial warming documented in an East Asian pollen record[J].Scientific Report,2014,4:3611.DOI:10.1038/srep03611.