泾河中游古耕作土壤的微形态特征研究

通过野外调查,应用偏光显微镜和图像处理软件等手段,结合理化分析,研究了泾河中游古耕作土壤的微形态特征。结果表明:古耕作土壤是中壤土;骨骼颗粒磨圆度好,以石英、长石等不易风化矿物为主,并含有石英复合晶、石英或长石的扁平状单晶等外来物质;细粒物质主要是粘粒和次生方解石。古耕作土壤的基本微垒结为海绵微垒结;根孔、虫孔发育,裂隙不发育;土壤形成物主要是铁质粘粒浓聚物和不同形式的次生方解石;前者的丰度和铁质浸染强度高于表土层和母质层。光性定向粘土极少量。

Micromorphological Features of Palaeocultivated Soil in Middle Reaches of Jinghe River

A study on micromorphological features of soil in the middle reaches of the Jinghe River was carried out in this paper by means of field investigation,chemical analysis and polarizing microscope.The results are as follows: the texture of the palaeocultivated soil is medium-loam;the skeleton in the palaeocultivated soil have good smooth surface and mostly consist of quartzes,feldspars etc.,and also have some compounded quartz grains and platy single crystal of quartz or feldspar;there are residues of plants and directional distributed excrements in the organic constituents.The shapes of the voids chiefly are cylinder,arch or equidimension.The basic microstructure of the palaeocultivated soil is spongy microstructure.Hollow butt and wormholes are very developed with few crannies.The palaeocultivated soil accumulates an abundance of clays.It contains some pedogenic calcite pedofeatures and quantity of clay nodules impregnated by iron.The optical directional clay only exists a little.