台灣北部桃園台地紅壤的黏土礦物特性

Clay Mineralogical Characteristics of Red Soils from TaoyuanTerrace in Northern Taiwan

曹崇銘(Tsung-Ming Tsao) ； 陳岳民(Yue-Ming Chen) ； 江凱楹(Kai-Yin Chian) ； 王明光(Ming-Kuang Wang)

《土壤與環境》 13卷1&2期 (2010/12) Pp. 43-57

https://doi.org/10.30058/SE.201012.0003

摘要

Red soils profiles developed on aged fluvial terraces in Taoyuan remained poorly understood due to the lack of information on the physicochemical properties, mineral species and particle size of lateritic and gravel soil layers under paleo-environmental conditions. The objectives of this study were to compare the physicochemical properties of lateritic and gravel soil layers and identify the composition and particle size of magnetic clay minerals by separation of high gradient magnetic separation (HGMS) for six red soil profiles. The soil textures are clay with low base saturation (BS) and cation-exchange capacity (CEC). Low magnetic susceptibility of red soils indicates that there is no magnetite (Fe3O4) or maghemite (γ-Fe2O3) present in the soils. Illite and kaolinite are the major clay minerals in clay fractions of red soils. The illite, kaolinite, gibbsite, quartz, goethite, and hematite were identified in clay fractions and nanoparticles by X-ray diffractions (XRD) analysis and transmission electron microscopic (TEM) investigations. From the chemical compositions of clay fractions (i.e., molar ratios of SiO2/Al2O3 and SiO2/R2O3 of clay fractions and the red soil features), these red soils developed from Taoyuan terrace can be considered as red earths and do not meet the criteria of laterite.

關鍵字

高嶺石 ； 三水鋁石 ； 針鐵礦 ； 赤鐵礦 ； 磚紅壤 ； 老沖積物台地

並列摘要

Red soils profiles developed on aged fluvial terraces in Taoyuan remained poorly understood due to the lack of information on the physicochemical properties, mineral species and particle size of lateritic and gravel soil layers under paleo-environmental conditions. The objectives of this study were to compare the physicochemical properties of lateritic and gravel soil layers and identify the composition and particle size of magnetic clay minerals by separation of high gradient magnetic separation (HGMS) for six red soil profiles. The soil textures are clay with low base saturation (BS) and cation-exchange capacity (CEC). Low magnetic susceptibility of red soils indicates that there is no magnetite (Fe3O4) or maghemite (γ-Fe2O3) present in the soils. Illite and kaolinite are the major clay minerals in clay fractions of red soils. The illite, kaolinite, gibbsite, quartz, goethite, and hematite were identified in clay fractions and nanoparticles by X-ray diffractions (XRD) analysis and transmission electron microscopic (TEM) investigations. From the chemical compositions of clay fractions (i.e., molar ratios of SiO2/Al2O3 and SiO2/R2O3 of clay fractions and the red soil features), these red soils developed from Taoyuan terrace can be considered as red earths and do not meet the criteria of laterite.

並列關鍵字

Kaolinite ； gibbsite ； goethite ； hematite ； laterite ； aged fluvialterrace