基于粘土矿物XRD分析的良渚古城城墙土特征及物源探讨  

Characteristics and source of city wall' s earth in the Neolithic Liangzhu City based on XRD analyses of clay minerals

作　　者：胡薪苹[1] 师育新[1] 戴雪荣[1] 王金涛[1] 刘斌[2] 王宁远[2] 

机构地区：[1]华东师范大学资源与环境科学学院,上海200062 [2]浙江省文物考古研究所,浙江杭州310014

出　　处：《岩石矿物学杂志》2013年第3期373-382,共10页Acta Petrologica et Mineralogica

基　　金：国家自然科学基金资助项目(41071134)

摘　　要：在野外观察、测量和系统采样的基础上通过粘土矿物、粒度及元素地球化学实验,分析了良渚古城城墙土的成分特征,并探讨了其物质来源。研究结果表明:①北城墙夯土层的粒度、地球化学元素及粘土矿物组合特征与区内馒头山、黄泥口土丘极为相似,均为粘土质粉砂,粘土矿物组合为伊利石-高岭石-蛭石和绿/蛭混层-蒙皂石型;垫土层则与区内广泛分布的生土层在各指标上表现出一致的特征。据此认为,城墙夯土层取土于附近土丘馒头山和黄泥口,而垫土层则就地取土于附近生土层。②馒头山等自然土丘由于地势较高经历了较强的氧化作用,而生土层是湖沼相沉积物,地势较低洼,处于弱还原的环境,因此二者的粘土矿物组成和结晶度、化学元素等都不同。良渚先民就地取生土层为城墙垫定基础后,并未用它来夯筑城墙,而是从附近馒头山等自然土丘上采取了更适合建筑的土来修筑城墙。Sampling was conducted according to field survey and measurement and, on such a basis, the authors studied the component features of the city wall＇s earth in the Neolithic Liangzhu City, and further discussed its source in association with the analysis based on experiments of XRD, grain size and geochemical elements. The results are as follows： @ Characteristics of grain sizes, geochemical elements and clay minerals are similar to those of Mantou and Huangnikou mounds, and the northern city wall＇ s earth is dominated by clay silt. Clay minerals comprising city wall＇ s earth belong to the combination of illite-kaolinite-vermiculite/mixture of chlorite and vermiculite-smectite. Padded earth＇s characteristics in northern city wall are similar to earth＇s characteris- tics of the fourth layer widely distributed in this area. It is therefore inferred that the source of the city wall＇ s earth was derived from somewhere near Mantou and Huangnikou mounds. （~） Mounds like Mantou went through strong oxidant activity because of its high elevation. The raw earth consisting of lacustrine-swamp facies went through reduction activity because of its low elevation, resulting in differences in mineral component degree of crystallinity and geochemical elements. The Neolithic people in Liangzhu area used the local earth only for the city wall＇s foundation, and they didn＇t use it to build the city wall directly. They chose the soil from mmewhere near mounds like Mantou, because they thought the soil there was more suitable to building city wall.

关 键 词：良渚古城 城墙土 XRD分析 粘土矿物 物源 

分 类 号：P575.5[天文地球—矿物学] K878[天文地球—地质学]