1. The major driving force promoting the formation of iron nodules is in situ weathering from saprolites by frequently alternating wetting/drying cycles, while illuviated iron only played a minor role in this formation.
本研究中生成铁瘤的主要机制乃是腐石在原处经频繁变动的乾湿交替作用后，崩解风化而化育生成，而洗入型的氧化铁则为生成铁瘤的次要力量。