Relative dating does not provide actual numerical dates for the rocks.Fossils are important for working out the relative ages of sedimentary rocks.Discover how geologists study the layers in sedimentary rock to establish relative age.
We'll even visit the Grand Canyon to solve the mystery of the Great Unconformity!Imagine that you're a geologist, studying the amazing rock formations of the Grand Canyon.A fossil can be studied to determine what kind of organism it represents, how the organism lived, and how it was preserved.However, by itself a fossil has little meaning unless it is placed within some context.Your goal is to study the smooth, parallel layers of rock to learn how the land built up over geologic time.
Now imagine that you come upon a formation like this: What do you think of it? How can you make any conclusions about rock layers that make such a crazy arrangement?
For example, based on the primate fossil record, scientists know that living primates evolved from fossil primates and that this evolutionary history took tens of millions of years.
By comparing fossils of different primate species, scientists can examine how features changed and how primates evolved through time.
Relative dating cannot establish absolute age, but it can establish whether one rock is older or younger than another.
Relative dating requires an extensive knowledge of stratigraphic succession, a fancy term for the way rock strata are built up and changed by geologic processes.
Historians, for example, know that Shakespeare's play Henry V was not written before 1587 because Shakespeare's primary source for writing his play was the second edition of Raphael Holinshed's Chronicles, not published until 1587.