花岗岩球状风化的形成机理新析

摘要

花岗岩球状风化现象在自然界比较常见，其成因国内一般认为受三维裂隙控制，出露地表接受风化时，由于棱角突出，角部受三个方向的风化，棱边受两个方向的风化，而面上只受一个方向的风化，故棱角逐渐缩减，最终趋向球形。国外也有其他成因认识，如 liesegang 现象、卸荷载、微裂隙、体积膨胀、后期风化作用等莫衷一是。本文通过认真观察，对比分析，总结出球状风化形成机理即亲水矿物吸水及失水造成的膨胀收缩的结果。%Granite spherical weathering phenomenon is common in nature,for which the genesis is generally believed to be controlled by three dimensional fractures in domestic.The granite is exposed on the earth sur-face to be in the weathering process.Due to the prominent arrises and horns,corner by the three directions of weathering,arris edge by the two directions of weathering,and only in one direction for the surface of weath-ering,so the arris edges and corners are gradually cut off to be in spherical ultimately.In abroad,there are other different kinds of genesis,such as liesegang phenomenon,load and unload,microfracture,volume ex-pansion,the late weathering mechanism etc.According to careful observation and comparative analysis,this paper has summarized that the result of the expansion and contraction caused by water absorption and loss is the reason for formation mechanism of spherical weathering.