【摘要】 利用土地质量地球化学调查的7种氧化物数据,对陕西渭河中下游流域内的黏土矿物进行能谱分析,建立了质量守恒方程组,将求解黏土矿物含量问题转化为求解线性规划最优解,以研究黏土矿物分布特征。结果显示:该方法简单易行,准确性较高;土壤发育处于幼年—中间阶段,主要黏土矿物是伊利石、蒙脱石、高岭石,次要黏土矿物为蛭石、绿泥石,其含量因地貌类型而不同,体现不同的风化过程。其中,渭北台塬以黑云母-绿泥石-蛭石为主;中低山区以长石-伊利石-蒙脱石-高岭石为主;秦岭北缘由2种风化过程共同作用而成;河谷区域则是2种风化过程均较弱。此外,黏土矿物分布特征还综合反映了土壤类型及其性质,标识了不同地史时期的冷干和暖湿古气候的交替变化。更多还原

【Abstract】 In this paper,the energy spectrum analysis of clay minerals in the middle and lower reaches of Weihe River in Shaanxi Province has been carried out by using 7 kinds of oxide data from the investigation of land quality geochemistry.And then,a set of quality conservation equations has been established,which transformed the problem of solving clay mineral content into solving the optimal solution of linear programming to study the distribution of clay minerals.The results show that this method is simple and accurate.Soil development is still at a relatively early stage.The main viscous minerals are illite,montmorillonite,kaolinite,while the secondary clay minerals are vermiculite and chlorite.The different type of landform cause the difference in clay mineral content,reflecting the different weathering processes.For example,the Weibei platform is dominated by biotite,chlorite and vermiculite.The middle and low mountainous areas are dominated by feldspar,mica,illite,montmorillonite and kaolin.The northern margin of the Qinling Mountains is composed of two weathering processes,while the valley area is weak in both weathering processes.In addition,the distribution characteristics of clay minerals also reflect the soil type and its nature,indicating the alternating changes of cold dry and warm ancient climate in different geological times.更多还原