Incipient ferralization and weathering indices along a soil chronosequence in Taiwan
Incipient ferralization and weathering indices along a soil chronosequence in Taiwan
复制标题
DOI：
10.1111/ejss.12363
复制
发表时间：
2016-09-01
影响因子：
4.2
通讯作者：
Chiu, C. -Y.
中科院分区：
文献类型：
--
作者：
Jien, S. -H.;Baillie, I.;Chiu, C. -Y.
绿岛是台湾东南部的一座火山岛，其低丘地形包括一个近水平阶地的垂直序列。我们沿着这个序列检查了八个剖面，从海拔约10米的海岸边缘最低阶地上的浅棕色壤土珊瑚砂到海拔约240米的最高阶地上的深红色酸性粘土。化学分析，微分铁提取物，薄切片，X射线衍射的粘土矿物和土壤化学风化和应变的指标表明，土壤发育进展的初级和次级层状硅酸盐的风化，通过在中间阶段的泥质岩，以产生越来越多的游离铁。Fe以游离的倍半氧化物的形式积累，并随时间结晶。在分类学上，土壤类型从桑迪珊瑚砂质土，经过Eutric Cambisol、Hypereutric Lixisol和Acrisol，到初期的Ferralsol（在土壤分类学上，Udipsamment-> Eutrudept-> Udalf-> Udultisol-> Udox）。这些剖面被解释为年代序列，尽管由于礁珊瑚对主要火成母岩的贡献较小且向上递减，这一点变得复杂。安山玄武岩基岩也有变化，在较高和较老的土壤类型和轻微的风成输入。区域海平面的相关性，C-14测年的碳酸盐在两个最低的台阶和估计当地的构造隆起表明，早期的铁铝土上台阶可能从约150万年。因此，在绿岛上，从粘质淋积的锐成土到初始的以倍半氧化物为主的铁红壤的转变似乎在100 - 200 ka内发展，这比通常要快。
The low hilly topography of Green Island, a volcanic island off southeastern Taiwan, includes an altitudinal sequence of sub-horizontal benches. We examined eight profiles along this sequence, ranging from pale brown loamy coral sand on the lowest bench that fringes the coast at an elevation of about 10m to deep, intensely red and acid clay on the highest bench at about 240 m. Chemical analyses, differential Fe extractions, thin sections, X-ray diffraction of the clay minerals and indices of pedochemical weathering and strain indicated that soil development progressed by weathering of primary and secondary phyllosilicates through argilluviation in the intermediate stages to the generation of increasing quantities of free Fe. The Fe accumulates as free sesquioxides, which crystallize with age. Taxonomically the soil types progress from sandy coral Arenosol, through Eutric Cambisol, Hypereutric Lixisol and Acrisol to incipient Ferralsol (Udipsamment -> Eutrudept -> Udalf -> Udultisol -> Udox in Soil Taxonomy). The profiles are interpreted as a chronosequence, although this is complicated by minor and upwardly diminishing contributions of reef coral to the mainly igneous parent materials. There are also variations in the andesitic-basaltic bedrock, and minor aeolian inputs in the higher and older soil types. Regional eustatic sea-level correlations, C-14 dating of carbonates on the two lowest benches and estimates of local tectonic uplift indicate that the incipient Ferralsols on the upper bench might date from about 150 ka. The transition through argilluvial Acrisols to incipient sesquioxide-dominated Ferralsols appears, therefore, to develop within 100-200 ka on Green Island, which is faster than usual.