Relative Dating and Ceramic Typologies

I have been asked a number of times how we archaeologists date our finds and sites. There are a number of ways researchers can accurately date an artifact; but many times more than not, objects cannot be absolutely dated and must be placed within a timeframe. We create typologies (classifications of objects based on characteristics) of ceramics and other artifacts to keep track of archaeological data on a large scale. In doing so, archaeologists can verify a site’s age by narrowing the window of time that an artifact found at the site would have been in use.  By cataloguing the distribution, frequency, and approximate ages of a site’s artifacts, one can determine how old the site is. Obviously this is an oversimplified explanation, but you get the point.

Currently I am working at a site that is dated to 1611 here in Virginia. It is one of those rare times when we actually have written documentation that proves the site’s age. However, elements of the site include later occupations and uses of the same land, which we would like to date. This is where relative dating and typologies can come in handy. While excavating a palisade wall ditch (which we know was originally dug-out in 1611 and re-dug some time later) I uncovered a piece of pottery in a portion of the ditch which we know had been constructed much later than 1611. We had already found a few other artifacts in the more recent portion of the ditch that gave us clues to the ditch’s age but this find gave us a much better idea.

bartmann jug - jamestown
Bartmann jug piece (photo by author)

The Bartmann jug (also referred to as Bellarmine jug) is a stoneware vessel used to store or transport food or drink. They originate in Western Germany and were manufactured for use and export during the 16th and 17th centuries. The jugs come in numerous forms and styles, but all have one defining feature: a bearded face mask icon, usually on the neck of the vessel. Luckily the potsherd I found contained the beard portion of the icon (see above). Bartmann (‘bearded man’ in German) masks tended to be very realistic and detailed in early versions of the jugs from Europe (Fig. 1), while later versions were very rudimentary and less lifelike (Fig. 2).

Figure 1
Figure 1 – Early Bartmann (photo: David Jackson, Creative Commons)
Figure 2
Figure 2 – Late Bartmann (photo: Creative Commons)

The beard featured on the piece I found is very basic and linear. This lets us know that the jug was made during the latter periods of Bartmann manufacturing. When we couple this knowledge with the other finds from the later ditch, we can get a much smaller window of time that the ditch construction occurred within. It’s all part of the fun of reconstructing the past based on scant material evidence!