摘要
基于河南省禹州市马沟洞2支石笋(MG-1与MG-40)24个^(230)Th年龄和1988个氧同位素数据,建立了研究区13.1—4.9 ka BP分辨率为2—14 a的石笋氧同位素时间序列。马沟洞石笋δ^(18)O的时间序列揭示季风降水在11.2—9.1 ka BP时段在波动中逐渐增加,9.1—4.9 ka BP季风降水显著波动但无明显长期趋势变化。YD事件、9.3 ka事件、8.2 ka事件记录与其他石笋δ^(18)O记录的一致性揭示末次冰消期—早全新世百年—千年尺度气候突变事件的大范围存在和共同的驱动因子。马沟洞全新世大暖期的δ^(18)O记录中检测出的13个数十年尺度的弱季风事件进一步证实全新世大暖期气候的不稳定性。与大气⊿^(14)C记录、NGRIP冰芯δ^(18)O记录的对比及周期分析揭示,太阳活动引起的太阳辐射变化和北半球高纬气候状况共同影响着亚洲季风的变化,ENSO活动及气候系统内部的相互作用也对东亚夏季风降水产生重要的影响。
Background,aim,and scope Henan Province,located in central China,is dominated by monsoonal climate,and has been regarded as the core region of Chinese ancient civilization.Stalagmite has advantages of absolute and high-precision chronology and abundant proxy indexes,and has been widely used to decipher the changes of Asian summer in the past.However,there are few stalagmite records obtained from this region till now and all of them are located in the hilly area of west Henan Province.Here,we present a high-resolution and precisely dated stalagmite δ^（18）O records attained from two stalagmites（MG-1 and MG-40） from Magou Cave,northern Henan Province,Central China.We reconstruct the history of monsoon precipitation during early to mid Holocene,characterize the climate instability of the Holocene Megathermal and investigate the possible driving forces and dynamics of the Asian Summer Monsoon（ASM） in the study region.We also examine the possible links existed between civilization succession and climate change.Materials and methods Two calcite stalagmites,MG-1 and MG-40,have been analyzed in this study.Stalagmite MG-1 is ~26 cm in height and ~9 cm in diameter,and MG-40 is ~4 cm in height and ~8 cm in diameter.We halved these two stalagmites using diamond wire saw.Twenty-four subsamples were drilled parallel to the growth plane using a hand-held carbide dental drill,and were dated with U-series methods on a plasma sourced multi-collector mass spectrometry（MC-ICP-MS）at the Institute of Global Environmental Change,Xi＇an Jiaotong University.The chemical procedure is similar to that described in Edwards et al（1987）,and the details on instrumental approaches were explained in Cheng et al（2013）.Here we use a linear interpolation to establish the chronology,and extrapolate the ages for the portions outside the U-series dates using the growth rate of adjacent segments.Subsamples for stable isotope analysis were collected with a high resolution computer-controlled micro-milling equipment（Micro-mill�
出处
《地球环境学报》
2016年第3期254-268,共15页
Journal of Earth Environment
基金
中国科学院重点部署项目(KZZD-EW-04)
国家自然科学基金项目(41271229)~~
关键词
石笋
Δ18O
气候变化
夏季风降水
全新世
马沟洞
stalagmite
δ18O
climate change
summer monsoon precipitation
Holocene
Magou Cave
