Stone distribution in a stony tableland soil
Stone distribution in a stony tableland soil
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DOI：
10.1071/sr9650131
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发表时间：
1965
期刊：
影响因子：
1.6
通讯作者：
J. Mabbutt
中科院分区：
文献类型：
--
作者：
J. Mabbutt
石质台地上的纹理对比剖面显示，A层的岩石集中，B层的岩石很少，下面的岩石明显复发。这块石头与下面的一块硅酸盐硬膜锈中的石头相同。只有轻微的土壤表面下降，形成了现在的人行道，其他石头似乎从未露出过。表层土壤的轮廓与来自地势较高的硅质层的岩石不一致。重矿物表明剖面为残留层，无石粘土B层不是沉积层。由于粘土地基的膨胀和收缩，剖面内的石块向上移动，这一点就解释了土层和石料分布之间的一致关系。似乎很少或根本没有相关的Gilgai地层，可能是由于厚重、质地粗糙的石质表面土壤的覆盖作用。漂白的A2层和盐积层在岩石置换后形成，表明下层土壤停止运动，湿润锋撤退，气候变得更加干燥。
Texture-contrast profiles on a stony tableland showed concentration of stone in the A horizon, very little stone in the B horizon, and marked recurrence of stone below. The stone was identical with that in an underlying silcrete duricrust. There had been only slight lowering of the soil surface to form the present pavement, and no other stone appears ever to have been exposed. The contours of the surface soil are inconsistent with stone derivation from a higher-lying siliceous horizon. Heavy minerals indicate that the profiles are residual and that the stone-free clay B horizon is not a depositional layer. Upward displacement of stone within the profile by swelling and shrinkage of the clay subsoil alone explains the consistent relationship between soil horizons and the distribution of stone. There appears to have been little or no associated gilgai formation, probably owing to the mulching effect of a thick, coarse textured, stony surface soil. A bleached A2 horizon and a horizon of salt accumulation developed after stone displacement, and indicate cessation of subsoil movement and withdrawal of the wetting front with change to a drier climate.