甘肃庄浪全新世黄土土壤物源分析及古气候恢复重建  

Provenance Analysis and Reconstruction of the Climate Change for the Holocene Loess profile in the Zhuanglang Country of Gansu Province,China

作　　者：王兆夺 黄春长 庞奖励 刘安娜 周亚利 查小春 WANG ZhaoDuo;HUANG ChunChang;PANG JiangLi;LIU AnNa;ZHOU YaLi;ZHA XiaoChun(Department of Geography and Tourism,Huanggang Normal University,Huanggang,Hubei 438000,China;Department of Geography and Tourism,Shaanxi Normal University,Xi’an 710119,China;Department of Geography,Shihezi University,Shihezi,Xinjiang 832003,China)

机构地区：[1]黄冈师范学院地理与旅游学院,湖北黄冈438000 [2]陕西师范大学地理科学与旅游学院,西安710119 [3]石河子大学理学院,新疆石河子832003

出　　处：《沉积学报》2020年第4期781-789,共9页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(41771110);湖北省教育厅项目(19Q187)。

摘　　要：通过对六盘山西侧黄土地区进行详细的野外调查,在甘肃庄浪县城北水洛河第三级阶地平坦地面发现出露厚度3 m的全新世风成黄土古土壤剖面。确定以此为基础进行黄土古土壤物源分析及古气候恢复重建研究。在对该剖面土壤与沉积学宏观特征观察分析描述的基础上,从上向下,以每2 cm连续采样,共获得170个样品。在实验室进行理化指标分析和OSL测年、粒度成分端元分析和时间过程小波分析。结果表明,该剖面全新世黄土古土壤中可以识别出4个端元组分。它们分别代表了沉积物沉积后就地风化成壤改造作用、后期的淋溶淀积作用、西北冬季风和区域北风作用下的沙尘暴沉积作用。其中反应短尺度气候变化比较敏感的端元1组分在时间尺度上呈现出0.3 ka、0.7 ka、1.2ka、1.5 ka、1.8 ka以及2.4 ka的震荡周期。该研究结果对于推动量化分析六盘山西黄土高原全新世黄土古土壤物源和恢复重建该区域气候变化规律具有重要意义,也可为其他地区全新世气候变化过程恢复重建和区域对比提供参考材料。Through detailed field investigation of the loess area on the western side of Liupan Mountains,a loess pa⁃leosol profile with a thickness of 3 m was found on the flat ground of the third⁃level terrace of the Shuiluo River in northern Zhuanglang county,Gansu province.The paleosol provenance analysis,paleoclimate restoration,and loess reconstruction were determined.Based on the observation and analysis of the macroscopic characteristics of the soil and sedimentology of the profile,170 samples were obtained from top to bottom and continuously sampled every 2 cm.Physical and chemical index analysis and OSL dating,particle size component end⁃member analysis,and time⁃process wavelet analysis were performed in the laboratory.The results show that four endmembers can be identified from the Holocene loess paleosol in the study area,and it represents the weathering and pedogenesis under the action of the East Asian summer monsoon after sediment deposition,the late eluviation dynamic characteristic,northwest winter monsoon,and regional north wind.Furthermore,the summer monsoon end member components on the Holo⁃cene time scale with oscillation periods of 0.3 ka,0.7 ka,1.2 ka,1.5 ka,1.8 ka,and 2.4 ka can be divided on the corresponding time scales.The results of this study are of great significance for promoting quantitative analysis of the Holocene paleosol provenance in the Loess Plateau of the Liupan Mountains and restoring and reconstructing the cli⁃mate change laws of the region.It can also provide reference materials for the restoration and reconstruction of the Ho⁃locene climate change process and regional comparison in other regions.

关 键 词：全新世 气候变化 风成黄土 粒度 物源 端元分析 小波分析 

分 类 号：P532[天文地球—古生物学与地层学] S152[天文地球—地质学]