When we find something buried in the ground that has no date on it, we need to gather other evidence to find out how old it might be. The layer in which the object was found and what it was found with can be vital clues to help us date it. We call this its Context.

Dating using context can be very simple - objects can be dated by the things they are found with. Objects found in the same context must have been buried at the same time and are of the same date.

Imagine burying objects in a time capsule and included is something with a date on it, such as a coin dated 2007. When the capsule is opened in the future it might not be possible to know the date of some of the objects. Because of the coin, it would be possible to say that the capsule was buried no earlier than 2007.

Geologists and archaeologists use context a great deal to date their finds. Zone fossils are used to date geological sites and coins and pottery can date archaeological sites.