Understanding soil and its deeper layers is crucial for environmental research. Current soil classification systems have limitations in categorizing layers below a certain depth. A study in Brazil looked at classifying both the upper and deeper layers of soil. They found that the current systems can be complemented by a classification system focusing on deeper material. This new system requires more knowledge on rock types but is more flexible than the existing one. The study suggests that future soil classification systems should consider the concept of 'whole regolith pedology' for a more comprehensive understanding of soil composition.