We can start by saying that weathering processes are most severe, active in tropical climes but almost hidden by the cover of vegetation as you can see in the picture below.
In this kind of place we are going to get more redox reactions than in a temperate climate.
This example was given to underlie the fact that what we can learn about weathering in a part of world can be completly different in an other part !
We call "Pedology" the study of soils ;
Soils are divisible into layers called horizons. There is thousand and thousands of different soils across the world... Weather conditions and geomorphic settings affect the thickness and the composition of these soils.
Soil formation is dominated by a physical processes are analogous to the percolation of coffee :
