西安狄寨塬全新世的古气候环境

Palaeoclimate environment during the Holocene in Xi'an Dizhaiyuan

对西安地区全新世以来的环境演变特征进行系统研究,建立该地区全新世以来黄土—古土壤沉积年代序列,揭示其反映的东亚冬、夏季风变迁规律,为预测西安地区乃至中国和全球未来环境的发展趋势提供依据.通过对西安白鹿塬刘家坡典型剖面全新世黄土—古土壤地层的岩性描述、地层划分和对比,结合泾阳县新庄村AMS14 C的年代测定和其他学者的测年数据,建立了该地区全新世以来黄土沉积年代序列.根据磁化率气候替代指标显示的曲线特征,阐述了这一替代指标在剖面上的变化规律,探讨了该黄土剖面所反映的东亚冬、夏季风强弱变化特点,论证和详细分析了西安地区全新世以来环境变化的特征和规律,进而对该剖面磁化率曲线特征与其他学者的孢粉谱建立的温度曲线对比,对西安地区全新世以来古气候的阶段性进行了详细分析和论证.将西安地区10 000年以来的气候演变划分为7个气候阶段.

The characteristics of environmental evolution were investigated and the loesspalaeosol deposition age sequence was obtained in Xi＇an area during the Holocene.The variation principle of winter and summer monsoon in East Asian was revealed,which provided reference for predicting the development trends of future environment in not only Xi＇an area but also China and the whole world.Lithology description along with stratum partition and comparison on typical section of Liujiapo Village in Bai Luyuan of Xi＇an were used for generating the loess deposition age sequence in the above region during the Holocene,combining the age determination data from AMS14 C in Xinzhuang Village in Jingyang County and previously reported.According to the character in the curve of substitution indication for climate susceptibility,the variation principle for this substitution indication was illuminated and the changing characters on strength of winter and summer monsoon in East Asian were discussed.Meanwhile,the characters and principle for environmental evolution in Xi＇an area were demonstrated and analyzed in detail.Additionally,through comparing the characters in the above susceptibility curve of this section with thermal curve established by other researchers based on the sporopollen spectrum,the palaeoclimate stage traits in Xi＇an area during the Holocene was verified with detailed study.The climate evolution is divided into 7stages during the 10000 years.