What you should know about absolute dating

Generally how the major absolute dating methods that we discussed work

What materials each can be used on, and specifically what event they date.

For the first three, roughly what periods of time they are useful for dating.

Very roughly how accurate and precise each is, especially compared to each other

What the error term in a date means (the numbers 68% and 95% should come to mind).

Generally how the uncertainty in dates affects what you can and cannot infer from them

The general idea of calibration of radiocarbon dates.

The general idea of some other issues in radiocarbon dating

The importance of ensuring a good association between a date and an event of interest

terminus post quem



Be able to make some general interpretations of scenarios involving absolute dates, like (but not limited to!):

Wood from a colonial house was radiocarbon dated to 1776 35 cal AD. Was the house standing during the revolutionary war?

Mrs. Smith brings you an archaeological axe or hammer head that she found on her property, made from a river cobble. She is willing to pay to find out how old it is. What do you tell her?

A dendrochronological study of ten roofbeams from different rooms in a pueblo in Arizona finds that the outer ring of the logs all date to between 1343 and 1346 AD. Charcoal in a cooking hearth inside one of the rooms gives a radiocarbon date of 1340 30 cal AD. Is there a problem here? What do these dates suggest about the order and timing of the construction of the building and the use of the hearth? If the charcoal had dated to 1100 30 cal AD, how might you explain that? There are at least two good possibilities.

You are excavating a site in China that appears to belong to the Yangshao culture, which has previously been dated from around 5000 to 3000 BC. Preservation is very good, and you have found lots pot sherds, flaked chert and obsidain tools, grinding stones made from basalt, thick layers of millet seeds in food storage bins, the bases of wooden posts that supported house roofs, charcoal from cooking fires, animal bone, human burials, and other materials. What method(s) might you use to date this site, and what materials would you use? What event or action would each approach date? What would be some pros and cons of each?