Final answer:
The principle of superposition, formulated by Nicolas Steno, helps determine the relative ages of rocks by stating that in undisturbed sedimentary layers, the oldest layer is at the bottom and the youngest at the top. It is an essential part of relative dating but does not provide numerical ages.
Step-by-step explanation:
The principle of superposition allows us to determine the relative ages of rocks. This principle was first articulated by Nicolas Steno in the 17th century and is fundamental to the field of geology, specifically in the practice of relative dating.
According to the law of superposition, in undisturbed layers of sedimentary rocks, the oldest layer is at the bottom and the youngest is at the top. This idea extends to the objects found within those layers, which allows scientists to determine which strata and fossils are older based on their depth relative to others.
Superposition does not provide numerical ages of rocks; rather, it allows for the ordering of strata and fossils from oldest to youngest. It is an important foundation for understanding the geological history and for piecing together the sequence of events on Earth. This method is critical in determining the rates of speciation of organisms by comparing fossil records in different strata.