华北北部花岗岩风化穴形成机制与环境意义

通过对华北北部3个地区花岗岩风化穴的调查研究，对其形态类型和成因作了详细讨论。研究区风化穴从形态上可分为底穴型(锅穴)、沟槽型、边墙型以及前三的组合。根据形态特征分析，首次提出锅穴主要与局部岩面上大气降水的长时间停留有关；沟槽型则与岩面流水有关，主要沿岩面半固定流路发育；边墙型大多起源于结构构造引起的岩石抗蚀性能的不均匀性。组合型在成因上则与前述3种机制中的一种或几种有关。风化穴作为裸岩表面差异风化的产物是一种广域型地貌景观，其空间分布并不指示特定的地理环境，但锅穴在形态特征上与环境要素关系密切，具有明显的环境意义。

Genesis of Granitic Tafoni of Northern North China and Its Environmental Significance

On the basis of the field investigation to the granitic tofoni located on three places in the northern part of North China, authors discuss detailedly their types and origins in this paper. The tafoni are divided into four types: basel tafoni, trough tafoni, wall tafoni and the assemble of the former three ones. According to the morphologic features we think that the basel tafoni (potholes) are formed by the differential weathering between the inside and outside resulting from the long-term existence of water in tafoni. Its morphologic features such as cross-section, vertical section and asymmetry of the insides et al. are related to some environmental factors. The trough tafoni (pseudokarst) are the courses of flow water due to precipitation where the moisture on rocky surface is higher than that on two sides. The wall tafoni mainly originated form heterogeneous resistance caused by the cheanges of texture and structure of rocks. Tofoni as wide-spreading ladforms have played an important role in the geomorphology, environmental geology.