一万年来西安神禾塬黄土磁化率的古气候环境

Palaeocimate Environment of Susceptibility of Loess Section Since 10 KaBP in Xi'an Shen Heyuan

通过对西安神禾塬鱼包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及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,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。

Loess deposition age sequence during the Holocene in the region is established by the description of rock character of loess-palaeosol stratum,the partition and contrast of stratum of section in Yu Baotou village of Xi＇an Shen Heyuan,and with the combination of age measuring of AMS14C in Xin Zhuang village of Jing Yang county and other scholars＇testing datums.According to the character of the curve expressed by substitution indication of climate of susceptibility,the changing regularity of this substitution indication in the section is expounded in this article.At the same time,the strength changing character of winter and summer monsoon in East Asian reflected by the loess section is explored too,then the character of the susceptibility curve of this section is compared with temperature curve of sporopollen spectrum established by other scholars. Also,on the base of careful analysis and verification to the palaeoclimate stage trait during the Holocene in Xi＇an area,7 climate stage nearly 10 000 years in Xi＇an area can be raised.