保蓄土壤水分在四川盆地水保林建设工程上的意义和途径

四川盆地水土保持林建设中普遍存在着效益较低的问题,其原因主要是土壤颗粒组成和结构影响下的土壤水分不足,而土壤水分又和林下枯落物、土壤有机质密切相关。因此,保护枯落层和增加土壤有机质含量是增强土壤涵水能力,提高营林效益的有效途径。     

紫色土再研究(Ⅰ)紫色土的母质-红层

从地质角度分析了红层的形成与出露,阐述了紫色土的可能分布.紫色土由红层紫色岩所形成,紫色岩是红层岩石的最重要成员,它们是在干热环境下形成.其中的染色物质是地壳中的含铁矿物在合适的地袁环境条件下与大气中的氧相互作用的产物.红层多在地史上的造山运动与海退之后出现,所以在全球有广泛的分布.各地红层紫色岩并无本质区别,只是沉积年代、质地、色泽以及岩层组合等有所差异,这些差异对紫色土性质的影响倒是值得进一步研究.

Abstract：

The formation and emergence of redbeds are analyzed from the geological perspective and the possible distribution of purple soil is discussed in this paper. Purple soil was derived from purple rocks,which are the most important members of redbeds. They were formed in hot and dried regions and produced from the interaction of iron-bearing rocks with atmospheric oxygen under appropriate conditions on the surface of the earth. Those conditions occurred after orogeny and regressions in the geological history and, therefore, the distribution of redbeds and purple rocks ought to be widespread in the world. The differences among redbeds at different places are not fundamental but rather are in texture, color, stratigraphic composition and age. How these differences affect the properties of purple soils are worth further investigation.