Any two units of stratification A and B have beside their stratigraphical relations the following three temporal relations as well:
*A is later/earlier than B*
*A is contemporary B*
*The temporal relation of A and B is not known*
The stratigraphical relations predefine the temporal relations of single units of stratification if they are in superposition to each other. If they are not in superposition the temporal relations have to be deduced from the analysis of other observations as structural relations or the dating of finds and samples. |