卧云铺:闪长岩球形风化
卧云铺闪长岩球形风化
闪长岩球形风化(Spherical weathering of diorite)
节理破坏了块状而均粒的1.3亿年前中生代西杜单元闪长岩的连续性和完整性,增加了岩石的可渗透性,促进了闪长岩的风化。几组不同方向的节理将闪长岩分割成众多多面体的小块,小块体的边缘和隅角从多个方向受到温度及水溶液等因素的作用,最先被破坏且破坏深度较大,久而久之,其棱角逐渐圆化,变成球形或椭圆形,这便是“球状风化”。它是物理风化和化学风化联合作用的结果,但以化学作用为主。该处闪长岩风化后形成的球形直径约50cm。
The joints destroy the continuity and integrity of the massive but homogeneous Mesozoic Diorite, increasing the permeability of the rock and promoting the weathering of the diorite.Several groups of joints in different directions divide the diorite into many polyhedral pieces. The edges and corners of the small pieces are affected by temperature, water solution and other factors from multiple directions, and are first destroyed with a large depth. As time passes, the edges and corners gradually become round and become spherical or elliptic, which is called “spheroidal weathering”.It is the result of the combination of physical weathering and chemical weathering, but mainly chemical weathering.The spherical diameter of the weathered diorite is about 50cm.