18 July 2011 - CT Scanning

CT scan of a mummy

This past week, we got a glimpse inside some of The Field Museum’s mummies and a few other artifacts.  Because we can’t physically unwrap the mummies without damaging them, we used a CT scanner to make three dimensional x-ray images of the objects.  Using software, we can then take a look at the 3D image to see what’s inside.  Inside we found grave goods such as a pot filled with what appears to be grain or residue from an evaporated liquid and what could be a necklace in addition to human remains, of course.  Although in one case, we found no remains where we expected to see a full skeleton.

This artifact at first appeared to be a Peruvian mummy bundle.  When we scanned the mummy, however, there was nothing inside the wrappings aside from packing material.  My guess is that whoever The Field Museum acquired this bundle from decided that he or she could make a larger profit by removing the bones from the bundle and selling each piece separately.  Another plausible explanation is that the removal of the bones occurred much closer to the time of the original burial.  Looting human remains is an old and widespread practice.  Ancient Egyptian elites built complex tombs to keep grave robbers from both stealing expensive grave goods and desecrating the remains of the occupant, while many Renaissance artists like Michelangelo studied the structure of the human body by performing autopsies.  The bodies these artists used were all too often disinterred from local cemeteries.  For whatever purpose, material gain or academic study, disturbing human remains was not uncommon.  It is possible, then, that the remains of this Peruvian mummy were removed by one of his or her contemporaries.

Yet, since conservation efforts typically seek to preserve an artifact rather than destroy it, there was no way for the anthropologists at the museum to know that they had purchased an empty bundle.  Until last week, that is.  The CT scanner revealed not a skeleton and grave goods that could tell us about the mummy’s lifetime, but rather a peek into the posthumous life of the artifact itself.

We also scanned some non-human artifacts such as a Pacific Island Rambaramp.  This figure is larger than life-size and may have been a way of memorializing or honoring ancestors who had passed away.  The scans showed the interior construction of the figure that we were not able to see from the outside.  We now know that coconut shells form the buttocks and the limbs are constructed from what look like long bamboo canes.

Similarly, we sent a drum made in the Marquesas through the CT scanner.  Currently, there are no surviving temple drums in the Marquesas, yet the use of these drums is experiencing a resurgence because of the nationalism associated with temple drumming.  From these images, we can help musicians in the Marquesas reconstruct a drum like the one housed at the Field Museum.