Currently I am in Rome doing an archaeological investigation of cremation remains. At this stage however, it means doing the internal excavation of cinerary urns. While I can’t discuss my own work too much at this stage (I’m doing pre-dissertation research and its all quite hush hush), I can discuss some of the issues and questions I’m facing. First, how do you excavate inside an urn? Second, what constitutes a single individual?
Let me begin by stating that cremation remains are not ashes. Modern cremation practices would have us believe that the body is reduced to a fine clean powder that one can romantically scatter at sea. Were you to do this in any other time period there would be large chunks of your deceased relative plopping into the water rather than fine dust swept into the ocean breeze. The reason for this misperception of what historic and prehistoric cremains look like is due primarily to the difference in processing. First, modern crematoriums use industrial furnaces that can get to temperatures of 870–980 °C (1600–1800 °F). After the incineration of the soft tissue and some of the hard tissue is completed, the dry bone fragments are pulverized by a machine called a cremulator, which processes them into “ashes”. Overall the process takes less than 2 hours. In the past however, the cremation took place on a wooden pyre and would require constant attention. While these could get quite hot (up to the lower end of the modern crematoriums), they required constant attention for up to ten hours and sometimes even longer if the weather didn’t cooperate. They also didn’t process the bones after the body was removed of soft tissue. What you are left with is a lot of small chunks of cracked and discolored bone (for a closer look at this check out this video that cremates a pig using ancient pyre methods). However, this is enough to get information about the individuals… it just takes a little more time and patience.
So to my first problem… how to excavate the inside of a cremation urn. It’s actually easier said then done. You excavate the exact same way that you would any other archaeological site, in small levels taking note of what is found at each level, photographing them and mapping them. The difference is that instead of working in a 1 by 1 or 2 by 2 meter area you have a 13 cm in diameter opening in which to get your tools in. This just means scaling down. There are no shovels or even trowels, instead you have teaspoons and various clay art tools or dental picks to work your way through the layers. It is like doing a mini dig. Once the bone is removed it is passed through a number of sieves at different sizes. Since there are many many small pieces, the bone is weighed rather than counted. All materials from the urn are kept, but bagged separately (i.e. a bag for bone, bag for terracotta sherds, bag for the ash and sand). You also use special terms, or at least you can. When excavating within an urn you dig in ‘spits’, but these are pretty much levels so I’ll just keep using that term. Luckily for me, I had a wonderful Masters advisor who actually taught us how to do the proper excavation and recording of cremated remains. Thanks Dr. McSweeney!
My second question and the one that I keep getting asked, is how to tell the number of individuals who are within the urn. This is slightly easier with inhumed remains as the individual may be laid out or curled up in a position that obviously shows how many are buried there (although for a good lesson on why this isn’t always true and why we must be careful even with inhumations see my post on the composite burials in Scotland). There are two ways of doing this. First you can look for duplicate elements. If you have three femoral heads or two right temporal bones then you obviously have more than one individual. This can be difficult since identification is harder, but it is the easiest way to determine the minimum number of individuals. The second way is to weigh the remains. McKinley (1993) did a study from modern crematoriums on the average weight of remains after a cremation. She found that after removing the < 2 mm portions, which are not studied in archaeological contexts, the average body ranged from 1000 g (female) to 2400 g (male) with an average of 1625 g. This means if the remains you found weigh substantially more, that there are likely more than one individual. However, this method must be cautioned when determining sex since many cultures don’t remove all of the cremains from the pyre, but instead take a token of the body for the urn and burial.
McKinley, J. (1993). Bone fragment size and weights of bone from modern British cremations and the implications for the interpretation of archaeological cremations International Journal of Osteoarchaeology, 3 (4), 283-287 DOI: 10.1002/oa.1390030406