Hunting Pyramids in Sudan

 Hunting Pyramids in Sudan

Over the past few years I have worked with a number of TV companies on shows that have highlighted the use of geophysics for archaeological investigation.  One of the most fun teams that has presented me with some of the greatest challenges to the use of both land and marine geophysics is led by Josh Gates at ExpeditionUnknown.  In his long-running series that airs on the Discovery Channel he has allowed me to run various geophysics in Dwarka (India), Namibia, and at various sites around the UK.

Early this year Josh asked if I would join him for a project in Sudan trying to find a lost pyramid.  Now you would think that it would be pretty hard to lose a pyramid, but it turns out that this might not be the case.  Pyramids are sometimes only partially completed or sometimes never really get beyond the foundations. They are often robbed of material to build other structures, let alone that they weather over time in the harsh desert environments where they are typically found.

The Nubian pyramids in Sudan were built by rulers of the Kushite kingdom from 1000BCE to 300AD.  While they have similar forms to those of Egypt the Sudan ones tend to be steeper sided and are constructed mainly out of the local coarse sandstone bedrock. The focus of this research project was the site of Nuri where it is thought that once over 80 pyramids may have stood marking the tombs of the royals from around 670BCE to 310BCE. The oldest, that of Taharqa (690-664BCE), a pharaoh of the 25^th Dynasty of Egypt and King of the Kingdom of Kush stands 50m tall and appears to contain a pyramid within a pyramid as seen from the stones eroding from the summit.  

One of the most interesting projects running at the site currently is led by Dr Pearce Paul Creasman who has an intrepid team of divers who are excavating the tomb of Nastasen.  Diving you may well ask?! Yes, because the nearby waters of the Nile and recent dam projects have caused the ground water level to increase to the point of flooding the tombs.  While I resisted the temptation of joining them (Josh did not) in zero visibility water that contains bits of old pharaoh my task was to find evidence for both the pyramid within a pyramid for Taharqa and also to search for a pyramid of a known king which could not be accounted for. 

For the task at hand in such dry conditions then ground penetrating radar was the tool of choice but since those who know me will also know I never trust just one technique, and especially if that is GPR. So, I also took along the trusty CMD Explorer electromagnetic ground conductivity meter as well.

The GPR was a Mala system with a 250MHz antenna.  Normally this should have been adequate in a dry, sandy environment to penetrate to at least a few meters.  I surveyed lines with a spacing of no more than 1m between lines and for most of the site a spacing of 0.5m between lines to form dense grids. An example of the results for a grid in front of the most northerly pyramid is shown below.  

Here you can see the sides of the tunnel stairway to the burial tomb close to the surface where it begins to descend.  While the edge is visible  the data shows the relatively limited penetration of the radar. This was curious and all I can think is that the wind-derived sand from the local coarse bedrock has winnowed the grains to leave a large proportion of the heavy metal minerals thus inhibiting the radar signal.

The results of the EM across the site showed much more promise.  The tomb entrances stand out clearly in the conductivity and magnetic susceptibility signatures against the backdrop area.  Interesting results were also obtained over a large flat and open area between the upstanding pyramids. The data here was consistent with there being a tomb entrance and foundations for a pyramid but clearly one does not exist – it is postulated that the missing pyramid was never built beyond the tomb and foundations. I hope that the dig team on site under the direction of Dr Pearce Paul Creasman will open up some test trenches to prove this in the near future.  

A cross section walked over the top of Taharqua’s pyramid also revealed the encased structure within the pyramid and now all that needs to happen is to extend this survey over the whole structure.

The survey, and especially the diving will be fully featured by Josh later this summer so watch out for the next program as part of Expeditions Unknown and pay careful attention to my new survey vehicle with its 1dp (donkey power) engine!