The principle stating that the oldest rocks occur on the bottom of an undisturbed rock sequence is known as

The answer is the superposition principle.

The superposition principle states that the oldest rocks occurs on the bottom of an undisturbed rock sequence. In other words, if the layers or rocks have not been disturbed, older rocks will lie beneath younger rocks. The principle is one of the most fundamental principles of geology. It could be very useful in determination of relative age of fossils.