how scientists can determine the age of rocks vs artifacts.



So I get how carbon dating works. What confuses me is if a tool is found that is made out of rock, how do scientists differentiate between the age of the rock itself and the age of the tool (when it was shaped)?

In: Chemistry

It’s not dated directly, but estimated by the sediment layer it is found in, along with the geological history like the time period in which tools of the sort were documented as being used.

They know a “artifact” is way older than a rock because they know somebody would have carved the rock by now so it must not be as old as the “artifact” they found nearby.

There’s no way to directly measure when a rock was shaped into a tool, but we can indirectly measure it a few ways. One would be to date the sedimentary layers the tool is found in. Another way would be to directly date the remains of organic materials found in the same layer of rock as the tool, or near the tool. For example, if we found a stone arrowhead next to the bones of an animal in the same layer of rock, we can date the bones directly and that will tell us the age of the tool.

Obsidian tools like arrowheads can be dated extremely accurately. When you chip obsidian that fresh obsidian begins to develop a rind of sorts as it’s exposed to water in the atmosphere. Much like carbon dating this happens at a very predictable rate. This in conjunction with superposition adds more accuracy. I’m not an expert I just took one class in college. I’m sure someone more educated can go into specifics.