磁山地区黄土-古土壤微形态特征及其古气候意义  

MICRO-MORPHOLOGICAL CHARACTERISTICS OF LOESS-PALEOSOL IN THE CISHAN AREA AND ITS PALEOCLIMATIC SIGNIFICANCE

作　　者：梁壮 任娜欧 段文凯 张海江 付野 张凤荣 王数 王清韵 Liang Zhuang;Ren Na’ou;Duan Wenkai;Zhang Haijiang;Fu Ye;Zhang Fengrong;Wang Shu;Wang Qingyun(College of Land Science and Techonology,China Agriculture University,Beijing 100193;Cishan Culture Museum in Wuan City,Wu'an 056302,Hebei)

机构地区：[1]中国农业大学土地科学与技术学院,北京100193 [2]武安市磁山文化博物馆,河北武安056302

出　　处：《第四纪研究》2020年第5期1264-1276,共13页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:41671216)资助。

摘　　要：为了探究磁山地区历史时期的古气候特点,本研究以河北省武安市磁山文化遗址区的黄土-古土壤为研究对象,该地区分布的黄土主要为晚更新世的马兰黄土和次生黄土,利用土壤切片图像处理分析系统和image-pro plus 6.0等软件对图像进行处理和分析,主要从微结构、孔隙特征及矿物成分这3个方面分析黄土和古土壤的微形态特征,并研究该地区黄土及古土壤的粒度和磁化率特征。得出结论如下:1)磁山地区的马兰黄土主要是粒状结构,孔隙度低,矿物以石英和长石为主;次生黄土主要有镶嵌微结构,还有典型的"斑状"微结构,孔隙度比马兰黄土小,粗颗粒仍然主要为石英、长石。2)马兰黄土中古土壤的粗颗粒主要为石英,孔隙壁沉淀较多方解石,存在发育良好的淀积粘粒胶膜,反映当时该地区气候温暖湿润,古土壤形成后,马兰黄土中的微形态特征、磁化率和粒度特征显示气候逐渐变得干冷,且冬季风强;次生黄土的微形态特点及磁化率特征,反映出次生黄土形成的后期比前期相对湿润。3)根据微形态和磁化率特征可知:磁山地区在晚更新世中期,气候从温湿逐渐变为干冷,晚更新世晚期则从干冷向相对温湿发展。In order to explore the characteristics of paleoclimate of the Cishan area and provide a basis for further research,this paper takes the loess-paleosol sequence in the Cishan Culture Site area of Wu'an City,Hebei Province as the research object.The distributed in this area is mainly Malan Loess and secondary loess in the Late Pleistocene.In this paper,two representative natural soil profiles are selected for the study,which are located in Niuwapu site(Niuwapu profile:114°03'13"E,36°34'52"N)and Xiwannian site(Xiwannian profile:114°08'39"E,36°36'54"N)respectively.The thickness of Niuwapu profile is 310 cm,of which 0~75 cm is modern soil,75~175 cm is loess layer,and 175~310 cm is paleosol layer.The thickness of Xiwannian profile is 155 cm,of which 0~90 cm is modern soil and 90~155 cm is loess layer.According to the natural stratification of loess-paleosol profile,soil samples are collected from the loess-paleosol sequence every 2 cm,and the undisturbed soil is made into standard thin sections by sieving grinding,slicing,abrading and sticking.Then,the images are processed and analyzed by the image processing and analysis system of soil slicing and the image-pro plus 6.0 software.This paper mainly analyzes the micromorphological characteristics of loess and paleosol from the aspects of microstructure,pore characteristics and mineral composition,and studies the grain-size and magnetic susceptibility characteristics of loess-paleosol in this area.The conclusions are as follows:(1)Malan Loess in Cishan Region is mainly granular structure with low porosity and weak weathering,there are main minerals as quartz and feldspar,reflecting the dry climate and strong winter wind during the formation period.Modified loess mainly has a mosaic microstructure,as well as a typical"phenocryst"microstructure.The porosity is smaller than that of the Malan loess,and the coarse particles are still mainly quartz and feldspar.(2)In Malan loess,the skeleton grain in the paleosol is mainly quartz,the pore wall precipitates more calcite,and

关 键 词：黄土 古土壤 微形态特征 古气候 黄土粒度和磁化率 

分 类 号：P534.63[天文地球—第四纪地质学] S159.2[天文地球—古生物学与地层学]