Measurements and projectile points

Submitted by Sammy Smith (

Buchanan et al 2012 PLoS ONE Tbl 2 part

Table 2 from Buchanan et al. article, An Assessment of the Impact of Hafting on Paleoindian Point Variability. Original table title: “Characters used in the study” (doi:10.1371/journal.pone.0036364.t002). (“Characters” means measurements.)

How do archaeologists seek to understand projectile points?

And, what’s a projectile point?

Projectile points are what many people call “arrowheads,” and are made of stone. But, many projectile points found in North America are too large to have been mounted on arrows and shot from a bow. Instead, for the most part, they were used as knives, or hand-cutting tools. Some were hafted onto longer handles and used as spears. Often, in the archaeological literature, a projectile point is called a PPK, which stands for projectile point/knife. This is a more accurate description than “arrowhead.”

So, how do archaeologists study projectile points?

Sometimes they make modern copies of them and use them for various activities, they study the damage those activities cause. For example, if you used a projectile point that had been hafted onto a handle to make a knife to butcher a deer carcass, that work would cause wear on the projectile point—perhaps some fine chips would come off, and maybe there would be some polishing.

Sometimes archaeologists study the kind of stone that was selected. Only certain kinds were used. And the preferred kinds may be available only in a few places and so the raw materials to make points may have been transported and traded over hundreds of miles.

Buchanan et al 2012 PLoS ONE Fig 2 part

Often, archaeologists make careful measurements of projectile points they’ve carefully recovered. They do this with great accuracy and in a systematic manner. This means that their measurements can be used by other researchers in other studies, because their measurements are replicable and standardized.

In a recent article* published free online, archaeologist Briggs Buchanan and four colleagues report on a study of North American Paleoindian points. They systematically measured 122 points found across the western USA. The drawing to the right is their Figure 2, which shows the many measurements they made of the points in their study. Each letter code refers to a particular measurement, shown in the graphic at the beginning of this entry.

Question: if you were making these kinds of measurements, what would you use to make them?

* The article is titled “An Assessment of the Impact of Hafting on Paleoindian Point Variability,” and the authors are Briggs Buchanan, Michael J. O’Brien, J. David Kilby, Bruce B. Huckell, and Mark Collard. It’s published by PLoS ONE, dated 2012, and included in volume 7, issue 5 as article e36364—and is online here (doi:10.1371/journal.pone.0036364). This issue of the SGA’s journal Early Georgia is accessible online for free, and includes a condensed introduction to the prehistory of Georgia.