I’m pleased to announce that I’ve just had another article published on StoneAgeMan! This latest post begins a discussion on archaeological dating methods, because learning about the past requires solid procedures for determining how old objects are.
I’d planned to cover all archaeological dating methods in one article, but that proved impossible: there are several ways to date archaeological finds, although most methods only work with specific types of samples. Thus, this first post concerns relative and radiocarbon dating methods.
Below is the most crucial information from the article.
Relative dating methods cannot determine exactly how old objects are, but only which objects are older and younger than others. In the StoneAgeMan article, I cover one relative dating method that relies on where a sample was found (stratigraphy), one that compares the physical characteristics of different artifacts (typology), and one that combines both of the aforementioned factors to track changes over time (seriation).
Of course, what archaeologists and the public most want is to attach specific years to archaeological finds. That’s where absolute dating methods – like radiocarbon dating – come in.
I spend roughly half of the StoneAgeMan article on radiocarbon dating, because it’s the most important absolute dating method in the archaeologist’s toolkit. It revolves around the radioactive decay of carbon-14 (14C), an unstable isotope of carbon that naturally breaks down into carbon-12.
14C is naturally produced when the sun’s energy interacts with nitrogen atoms in the earth’s atmosphere. Plants and animals acquire 14C while they’re alive, and their 14C content reaches an equilibrium with the environment.
When plants and animals die they can no longer replace the 14C that’s lost to radioactive decay. Thus, scientists can measure the amount of 14C left in an organic sample; and, by comparing this with the background 14C level in the atmosphere, estimate how long ago that organism died.
I go into much more detail in the StoneAgeMan post, so you should read it if you want to learn more! I’ll be writing about archaeological dating methods again in the future, starting with dendrochronology, or tree-ring dating.