What is the globular weathering of granite and why is it a "globular" strange name?
Thermal expansion and contraction is a cause of rock collapse in rocks, especially in tropical desert areas. Many different types of weathering, including granular disintegration, spherical weathering, stripping weathering and tectonic structures, can be explained by the principle of thermal expansion and contraction. However, most of the current field evidence shows the opposite conclusion. Granular disintegration, spherical weathering, stripping weathering and spallation structures have been found far beyond the depth of the sun's thermal effects. Experiments show that only rely on heat and cooling, weathering effect is very small, the process is slow, and when there is water, it almost immediately have an impact. Although the stratified structure was considered to be the product of sunshine, it has been recognized for many years that they are unloading, that is, the result of pressure release. However, there is a lot of evidence that the unloading hypothesis is not always applicable. The fault and lateral squeeze in the crust seem to serve as another explanation for the stratification.
Weathering is divided into biological weathering, chemical weathering and physical weathering. Ballistic weathering is divided into different weathering types according to different genesis
So that the rock destroyed and changed the various physical, chemical and biological effects. Generally can be defined as the surface or near the surface of the room temperature conditions, the rock in situ disintegration or alteration. The difference between disintegration and alteration reflects the difference between physical and chemical effects. The physical action involves rock breaking without involving any decomposition of rock-forming minerals. In contrast, chemical action means alteration of one or more minerals. The weathering produces a surface material that is different from the parent rock in the structure or composition. Weathering zone is called topsoil or residual soil. The lower limit of weathering is called weathering. The weathered process is very complex and usually occurs at the same time, causing the disintegration or decomposition of the rock. For the sake of convenience, weathering can be divided into physical (or mechanical) weathering, chemical weathering and biological weathering.
Spheroidal weathering (spheroidal weathering): the rock was spherical, from the table and the layers of weathering peeling phenomenon. It mainly occurs in granite, diabase and some sandstone. Fracture cutting in different directions, rock, water, gas and various microbial invasion along the cracks, resulting from the table and the layers of weathering peeling. As the surface area of the rock mass is larger, the strength and depth of the weathering are relatively large, so that the part of the rock mass is not subject to weathering. After the ball-like weathering debris material is stripped, the residual spherical rock block is called "stone egg".
