昆明玄武岩红土物质组成的剖面特征

在对昆明某地玄武岩红土进行现场勘察的基础上，对其剖面的物质组成取样进行了研究。结果表明：玄武岩红土剖面的物质组成由地表向下呈有规律的变化，化学成分为SiO2,Fe2O3,AI2O3为主，随剖面深度的增大，SiO2逐渐增大，Fe2O3和AI2O3逐渐减少；烧失量、pH值、比表面积、阳离子交换量都逐渐减小，颗粒组成上细下粗，具中等分散性，粘粒含量不高，天然含水率小，土颗粒密度大，低塑性，不具膨胀性，有一定的崩解能力。这充分反映了同一剖面上红土化作用从上到下逐渐减弱的变化规律。

The Section Properties of the Substance Composition of the Basalt Laterite in Kunming Area

This paper analyses the substance compositing of the basalt laterite section, based on site investigation the basalt laterite in Kunming area. The research results shows that the substance compositions of the basalt laterite section exists the change regulations from the ground surface to deep, SiO 2 and Fe 2O 3 and Al 2O 3 are the main chemical compositions. The SiO 2 increases gradually, but the Fe 2O 3 and Al 2O 3decrease gradually, the burning quantity, the pH values and the cation exchange capacity decrease gradually with the increasing of the section depth. The grain compositions of the laterite section is thin up and thick deeply, the desperse is mediate, the clay centent and the natural moisture centent and the plastic are low, the specific gravity is larg, it does not have the swelling and has the definite collapse. It fully responses that the laterization of the same section decreases gradually from the ground surface to deep.