6 relative dating principles
6 relative dating principles - Cam2cam arab dating
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.
The highest layers tell them what happened more recently, and the lowest layers tell them what happened longer ago.Let's say, in this set of rock strata, that we found a single intrusion of igneous rock punching through the sedimentary layers.We could assume that this igneous intrusion must have happened after the formation of the strata.We do this all the time in our regular day to day lives.For example, lets put the following movies in order of relative age from oldest to youngest: Twilight, Finding Nemo, the Avengers, the Hunger Games.Since we assume all the layers were originally horizontal, then anything that made them not horizontal had to have happened after the fact.
We follow this same idea, with a few variations, when we talk about cross-cutting relationships in rock.
Free 5-day trial Discover how geologists study the layers in sedimentary rock to establish relative age.
Learn how inclusions and unconformities can tell us stories about the geologic past.
Geologists use this type of method all the time to establish relative ages of rocks.
Now, what if instead of being horizontal, this rock layer was found in a tilted position?
Let's say we find out, through numerical dating, that the rock layer shown above is 70 million years old.