Question

what are the middle rock layer called if the top is the youngest and the bottom is the oldest

Answer 1

In the context of geological layers or strata, the middle rock layers are referred to as "intermediate" layers. The principle of relative dating suggests that in a sequence of sedimentary rock layers, the layers at the top are the youngest, while those at the bottom are the oldest. Therefore, the middle layers can be thought of as intermediate between the youngest and oldest layers. In some contexts, these layers may also be referred to by the specific geological time period they represent (e.g., Jurassic, Cretaceous) or by descriptive terms like "middle strata."