Relative dating is used to determine the
Students should be able to understand the principles and have that as a background so that age determinations by paleontologists and geologists don't seem like black magic. Geologists in the late 18th and early 19th century studied rock layers and the fossils in them to determine relative age.William Smith was one of the most important scientists from this time who helped to develop knowledge of the succession of different fossils by studying their distribution through the sequence of sedimentary rocks in southern England.These changes typically occur so slowly that they are barely detectable over the span of a human life, yet even at this instant, the Earth's surface is moving and changing.
Please remember that all dating methods, even those termed "absolute," are subject to margins of error. That is a very small amount of possible error range. Modern studies almost always use two or more methods to confirm dating work and to build confidence in the results obtained.
It wasn't until well into the 20th century that enough information had accumulated about the rate of radioactive decay that the age of rocks and fossils in number of years could be determined through radiometric age dating.