杭州地区新构造运动与红壤分布的关系

Effects of Neotectonic Movement on the Formation and Distribution of Red Soil in the Hangzhou Area

杭州附近发育良好的红壤均分布在山区外围,处于新构造运动的升沉过渡地段,这一地段的各种条件有利于红壤的形成.从典型红壤的分布带来看,可以说明杭州倾伏复向斜层构造,在新构造运动中,沿轴向又继续向东北倾伏.新构造上升量的差异,还可使局部红壤的性状不同.杭州地区古老断层的复活,将侵蚀面分割并伴以不等量的上升,所以相同高度的土壤,不一定绝对年龄相同.新构造运动影响土壤的垂直分布还表现为:高级侵蚀面上,较近期发育的黄壤之中夹有被抬升的古红壤残迹:平原中有下沉的埋藏红壤等,作者根据上述情况,认为土壤学方法也可做为研究新构造运动的一种有效手段.

In the area near Hangzhou city, typical and well developed red soils are always found in the lower hilly area-the periphery of the mountains. The same phenomenon may be true of many other places. The reason is that this region has all the natural conditions favorable to the development of red soils. Based on the distribution of red soils, it is found that the inclined Hangzhou synclinorium leading to the horse-shoe outcrop in the geological map continues to incline in the neotectonic movement. The symmetric central line of red soil distribution zone just coinsides with the axis of the old geological structure, Hangzhou synclinorium. The strike of this line is N50°E. Its northeastern end just passes the centre of West Lake and its southwestern end just passes the highest peak of this area-the Tianzhu Mountain. These interesting facts can only be explained from the neotectonic upward and downward movement. Denudational surface is cut by the revivedold faults, between which uneven neotectonic uplift leads to different heights of surfaces. Therefore these soils on the surfaces of similar height are not necessarily of similar absolute developing age. So the pedology can be used as an effective methodin the study of ncolectonic movement.