Live xxx couple chat room - Problems with relative dating
Geologists find the cross-cutting principle especially useful for establishing the relative ages of faults and igneous intrusions in sedimentary rocks.
Sometimes, geologists find strange things inside the strata, like chunks of metamorphic or igneous rock.
Let's say we find out, through numerical dating, that the rock layer shown above is 70 million years old.
We're not so sure about the next layer down, but the one below it is 100 million years old. Not exactly, but we do know that it's somewhere between 70 and 100 million years old.
Let's say, in this set of rock strata, that we found a single intrusion of igneous rock punching through the sedimentary layers.