How old items can have archaeological value?

Question

How old items can have archaeological value?

Answer 1

They tell us a surprising amount about the people who lived there.  Try this: take a look around your house.  What do the objects there say about you?  Based purely on what you have and don't have in there, an anthropologist can tell what gender you are, how old approximately you are, what your socio-economic status is, what country you live in, if you are from a foreign country, what your educational level is.  And an athropologist who has never seen a modern, western house before will also be able to tell you the function of each of the rooms, after some thinking and investigating.  They'll probably get some stuff wrong, but "kitchen", "bathroom", and "bedroom" will be easy.

That's pretty much what archaeologists do.  By looking at the stuff left behind, and where it is, we can learn a lot about the people who left it there.  We can also look closely at the evidence and get more information: the wear marks on tools can tell us what they were used for, and there might be residue left on pottery that will tell us what was stored there.  It doesn't even have to be all that old.  Generally, at my digs, we don't care so much about modern stuff, except as it shows that our site has been contaminated.  But if it's older than fifty years, it's an artifact (sorry, grandma).

Answer 2

They do not have to be very old at all.  There is no set age to determine archaeological value.  I was working on an ecological study site in Puerto Rico and we were instructed never to remove anything that could possibly be 50 years old or older as it was determined to have value by the archaeologist working in the area.