中文摘要：

通过对河南西部栾川县鸡冠洞2009年10月～2012年10月3个完整水文年的大气降水、洞穴滴水氢氧稳定同位素及洞穴现生碳酸钙δ18O的连续监测,探讨研究区岩溶记录的夏季风水汽源δ18O变化特征的气候意义.结果表明：1）栾川地区大气降水δ18O在研究时段内变化范围为1.2‰～-16.1‰,夏季（7～9月）大气降水δ18O加权平均值-10.8‰;鸡冠洞中滴水δ18O变化范围为-7.3‰～-11.9‰,平均值-9.4‰;鸡冠洞中现生碳酸钙δ18O变化范围为-6.6‰ ～-10.1‰,平均值-8.7‰;研究区大气降水、洞穴滴水和洞穴现生碳酸钙的δ18O变化趋势基本一致,表现为夏秋偏轻冬春偏重.2）栾川地区大气降水线为：δD=8.10 δ18O＋ 10.51,接近全球大气降水线.3）研究区大气降水中δ18O的雨量效应不显著,但对环流效应记录敏感,响应2009年10月～ 2010年10月E1 Ni（n）o和La Ni（n）a的转换过程,El Ni（n）o期间研究区大气降水、滴水和现生碳酸钙的δ18O显著偏重,且大气降水过量氘（d）明显偏高,而La Ni（n）a期间的δ18O和过量氘（d）变化特征则相反.

英文摘要：

An understanding of the processes that control equilibrium fractionation of oxygen isotopes in water and carbonate species is essential for the proper interpretation of speleothem δ18O,and is best complemented by study of site-specific cave processes.Hence,the oxygen isotopic compositions of the meteoric precipitation,cave drip water and modern calcite deposition from an in situ multiyear （from October 2009 to October 2012） monitoring program in Jiguan cave have been examined.2 drip sites （LYXS and TGBD） in Jiguan cave were monitored every 2 months,and ultimately 114 samples of meteoric precipitation,27 samples of drip water and 31 samples of modern calcite depositions were collected for determination of oxygen isotopic composition.The Jiguan cave （33°46′N,111°34′E; 900m a.s.l,at the entrance） is located in Cambrian limestone host rock 4km southwest of the city of Luanchuan Henan Province,Central China,near the boundary between the northern subtropical humid zone and the southern warm semi-humid zone in China.This area is strongly affected by the Asian monsoon system.Located within the typical East Asian monsoonal zone,the area around Jiguan cave typically has cold/dry winters and warm/wet summers.Most of the rainfall （ca.78％） occurs during the summer monsoon season （from May to October）.The mean annual temperature and precipitation recorded at a nearby meteorological station are 12.1±0.9℃ and 846±181mm （1957 ～2009）,respectively.Studies have shown that：（1） The δ18O of meteoric precipitation ranged from 1.2‰ ～-16.1‰,and the average of the weighted δ18O in summer is-10.8‰; The δ18O of drip water ranged from-7.3‰ ～-11.9‰,and the average is-9.4‰; The δ18O of modern calcite depositions varied between-6.6‰～-10.1‰,and the average is-8.7‰.The seasonal variation of three indexes is clear and coincident,showing the increase of stable isotope values during the winter season and the decrease of stable isotope values during the summer monsoon season.（2