Pedogenic alterations of illitic minerals represented by Radiocaesium Interception Potential in soils with different soil moisture regimes in humid Asia
Pedogenic alterations of illitic minerals represented by Radiocaesium Interception Potential in soils with different soil moisture regimes in humid Asia
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DOI：
10.1111/j.1365-2389.2008.01098.x
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发表时间：
2009-02-01
影响因子：
4.2
通讯作者：
Kosaki, T.
中科院分区：
文献类型：
--
作者：
Nakao, A.;Funakawa, S.;Kosaki, T.
磨损边缘部位可以是不同气候下土壤中伊利石矿物变化的重要指标，因为众所周知伊利石矿物会通过蠕化作用扩大磨损边缘部位。我们调查了土壤粘土（< 2 μ m）的相对丰度，放射性铯拦截潜力（RIP）的方法，并确定矿物学因素控制其量（代表RIP）的土壤下的ustic土壤水分制度（北方泰国，TH）和udic制度（日本西南部，JP;印度尼西亚东加里曼丹，ID）在潮湿的亚洲。我们发现RIP和矿物学或化学指标之间存在三种不同的相关性：正相关（伊利石矿物和Cs固定能力的量），负相关（高岭石和热柠檬酸盐可提取的Al-Si的量）和无相关性（DCB氧化物的量）。与各地区RIP对数相关性最好的变量是Al-cit-Si-cit（JP）、伊利石矿物量（TH）和高岭石量（ID）。在TH的土壤水分状况下，几乎没有蛭石化，磨损边缘站点（或RIP）和伊利石矿物的量和非常小的Cs固定能力之间的直接相关性证明了这一点。一个明显的旱季限制水的浸出，这可能会减少伊利石矿物的蚀变。对于ID土壤下的一个udic土壤水分制度，伊利石矿物天气形成蛭石，这是反映在扩大的磨损边缘网站。然而，对于JP土壤，羟基铝夹层减少磨损的边缘网站通过蛭石化形成。羟基铝聚合物从蛭石层中的释放可以引起磨损边缘部位的再暴露，这在灰化过程中可以是渐进的。
A frayed edge site can be a significant indicator of alterations in illitic minerals in soils evolving under different climates, because illitic minerals are known to enlarge the frayed edge site through vermiculitization. We investigated the relative abundance of this site in soil clays (< 2 mu m) using Radiocaesium Interception Potential (RIP) methodology, and determined the mineralogical factors controlling its amount (represented by RIP) for soils under ustic soil moisture regimes (northern Thailand, TH) and udic regimes (southwestern Japan, JP; East Kalimantan in Indonesia, ID) in humid Asia. We found three different correlations between RIP and mineralogical- or chemical-indices: positive (amount of illitic mineral and Cs-fixing capacity), negative (amount of kaolinite and hot-citrate extractable Al-Si) and no correlation (amount of DCB-oxides). The variable that correlated best with the logarithm of RIP in each region was Al-cit-Si-cit (JP), amount of illitic mineral (TH) and amount of kaolinite (ID). Under an ustic soil moisture regime in TH, there was little vermiculitization, as was evidenced by the direct correlation between the frayed edge site (or RIP) and the amount of illitic minerals and the very small Cs-fixing capacity. A distinct dry season restricts water leaching, which may reduce alteration in illitic minerals. For ID soils under an udic soil moisture regime, illitic minerals weather to form vermiculite, which is reflected in the enlargement of the frayed edge site. However, for JP soils, hydroxy-Al interlayering reduces the frayed edge site formed through vermiculitization. The release of hydroxy-Al polymers from vermiculitic layers can induce the re-exposure of the frayed edge site that can be progressive under a podzolization process.