从新构造运动观点论钱塘江阶地古红土资源

阶地古红土在华南分布很广,是一项重要资源。本文以钱塘江中下游为例,查明:阶地古红土分布决定于局部新构造运动升沉量与构造断块活动;愈到下游,古红土土层愈厚;在每一地段,阶地愈高,红壤化作用愈深,表现在铁的活化度（Fe_o/Fe_d）减低,粘粒的 SiO₂/Al₂O₃变小,酸性与粘性增强等。按新构造运动抬升时间与幅度,古红土还可划分为Q₂与Q₃两类,其上土壤的理化性质、作物的适种性及开发条件都不相同。二者的面积比（Q₂/Q₃）则与各区域新构造运动特点有关。

ON THE RED PALEOSOL RESOURCE ON TERRACES OF THE QIANTANG RIVER

The red paleosol is widespread on river terraces in South China. It is an important resource. From the research work in the area of the middle and lower reaches of the Qiantang River the author found that:1.The distribution regularity of the red paleosol is decided by the uplift and subsidence range of neotectonics or by fault movement;2.From the upper reaches to the lower reaches, the depth of the soil profile of the red paleosol increases gradually (Fig. 3);3.On the upper terraces, the laterization often becomes stronger. This is shown by the lower SiO2/Al2O3 ratio of clay, the weaker iron activity (Fe0/Fed) the lower clay content and the lower pH value.The red paluosol can be divided into two types-Q2 and Q3. Soils derived from them aredifferent in properties. Therefore the crop choice and the land resource exploitation are also different. Besides, statistic data reveal that the area ratio of Q2/Q3 in different places changes with the characteristics of the neotectonic movement.