【摘要】 四川盆地的红色古风化壳,可分为三个风化带。与紫色土相比,其细粘粒增加80%以上,塑性指数高2.44—3.02%,与下伏岩相比土体中Si、Al、Fe、Ti相对聚集,而Ca、P、Mn、Na、Mg、K相对淋洗。古风壳土体中Al的含量和粘粒甲Al、Fe含量,依第Ⅲ、第Ⅱ、第Ⅰ风化带序列增加,而Mg、Ca、K、Na、P、Mn和粘粒中Si的含量则反之,同时Al、Fe含量及其聚集值和Ca、Mg、K、Na、P的淋洗值表明,处于高海拔的古风化壳大于低海拔的古风化壳。更多还原

【Abstract】 The intact section of the aeient weathering crust in Sichuan Basin can be delimited into three strata, i.e, those of elastic clay (the 3rd stratum), the elastic brccia-cla-stic clay (the 2nd stratum) and the elastic breccia (the 1st stratum).The silt content of the ancient weathering crust is lower by about 15%, the fine clay content higher by more than 8% and the plastic index higher by 2.44—3.02% than those of the purplish soils derived from purple rock in the same region. The ancient weathering crust is relatively stronger in the accumulation of Si, Al, Fe and Ti and leaching of Ca, Mg, K and Na, as compared with its parent rocks underlying.The Al and Fe contents in soil material and clay fraction of the crust are increased in the follow order: 3rd stratum>2nd stratum>1st stratum; while the Ca, Mg, K,Na and Mn in soil material and Si in clay fraction of the crust are increased in a opposite order. At the same time, the contents and accumulation amounts of Al and Fe and the leaching amounts of Ca, Mg, K, Na and P in the crust at a higher altitude are generally higher than those in the crust at a lower altitude.更多还原