How accurate a date an archaeologist can give for an artifact depends upon what it is and what additional information is associated with it. If there is no organic material available for radio-carbon dating, an archaeologist can give only a general age if it is the right kind of artifact.

Some artifacts go through periodic changes of style (just think of cars and clothing). This happened in the past, too. The two types of artifacts that archaeologists can use to give an approximate age are projectile points and pottery sherds.

The term “projectile point” includes spear points, dart points, and arrow points. Spear points are the largest and usually are stemmed or fluted. These were made between 12,000 and 8,000 years ago. Dart points are intermediate in size. They were usually notched but a few styles are stemmed. These were made between 8,000 and 2,000 years ago. Arrow points are the smallest, and are usually notched although some unnotched “triangular” points are occasionally found. These were made between 2000 and 300 years ago.

Other artifacts such as mauls (often called hammerstones or pemmican pounders) were made the same way 12,000 years ago as they were 400 years ago. They do not show any stylistic difference through time so it is impossible to tell how old those kinds of artifacts are.