A Study of Weathering in a Soil Derived from a Biotite-Hornblende Rock
A Study of Weathering in a Soil Derived from a Biotite-Hornblende Rock
复制标题
黑云母角闪岩土壤风化研究
作者：
M. Wilson
摘要：通过光学、X 射线、化学、红外和差热方法对因弗内斯郡 Rehiran 附近的黑云母角闪石岩石上形成的静止土壤剖面中黑云母的风化进行了研究。在 C 层中观察到直接转变为水黑云母。这涉及所有存在的二价铁的氧化以及随后三价铁离子从八面体片中的移动。在 B 层中，风化进行到完全膨胀的 14A 相，这被确定为 1:1 比例的层间蛭石-绿泥石。化学分析表明，这一阶段伴随着镁的大量添加，其中大部分形成水镁石状夹层。在酸性更强的表面层中，这些夹层往往会分解，从而产生更多的蛭石产品。简要讨论了这种类型的黑云母风化可能产生的一般影响。
Abstract The weathering of biotite in a sedentary soil profile developed on biotitehornblende- rock near Rehiran, Inverness-shire has been investigated by optical, X-ray, chemical, infrared and differential thermal methods. In the C horizon a direct transformation to hydrobiotite was observed. This involves oxidation of all the ferrous iron present and subsequent movement of ferric ions from the octahedral sheet. In the B horizon weathering proceeds to a fully expanded 14A phase and this was identified as interstratified vermiculite-chlorite in a 1:1 ratio. Chemical analysis indicates that this stage is accompanied by a substantial addition of magnesium, much of which goes to form the brucite-like interlayers. In the more acid surface horizon these interlayers tend to break down thus yielding a more vermiculitic product. The possible general implications of this type of biotite weathering are briefly discussed.