西安地区泾阳南塬全新世黄土剖面磁化率反映的古气候

Palaeoclimate Reflected by Susceptibility of Holocene Loess Section in Jingyang South Plateau of Xi'an Region

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,通过对西安地区泾阳南塬寨头村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AMS14C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10000年以来的气候演变划分为7个气候阶段。

In order to provide a basis for predicting the future environment development trends of Xi＇an area or China and the global, loess deposition age sequence during the Holocene in the region was established by the descrip- tion of rock characters of loess - palaeosol stratum, the partition and contrast of stratum of typical section in Zhaitou village of Xi＇an region Jingyang south plateau . Combined with age measuring of AMS^14C and other scholar＇ testing datums, according to the characters of the curve expressed by substitution indication of climate of susceptibility, the changing regularity of this substitution indication in the section was expound. At the same time, the strength changing characters of winter and summer monsoon in East Asian reflected by the loess section were explored, the characters and laws of environment changing in Xi＇an area during the Holocene were demonstrated and minutely analyzed, then the character of the susceptibility curve of this section was compared with tempera- ture curve of sporopollen spectrum established by other scholars. At the same time , on the base of careful analysis and verification to the palaeoclimate stage trait during the Holocene in Xi＇an area,7 climate stage nearly 10000 years in Xi＇an area could be raised.