Yes, it’s been a long time.  Too long. 

Followers of the Deep Roots project may have been wondering why there hasn’t been a blog post for yonks (that’s a technical term, of course).  Has the project come to end?  No.  Has the team run out of things to say?  No.

There’s been plenty of activity going on behind the scenes despite the best efforts of Covid 19 to throw us off course.  Members of the project team have been at work in labs at Liège, Royal Holloway (London), Aberystwyth, Edinburgh, Hannover, the British Museum and Liverpool.  Sand, stone and wood are being examined carefully for the clues they hold to the age, formation and human activities at the sites excavated since 2017. And for the first time since the pandemic, flights have been booked for more field work in what will be the final season, bringing the data gathering to a close. 

So why no blogs for so many months? 

The fault is mine.  For more than a year now I’ve been on a national committee reviewing all archaeological research by academics in the UK, including its benefits to society.  It’s a big stock-taking that happens every five years with consequences for research funding across UK universities.  But that all-absorbing role has ended now, so let me bring you up-to-date with what’s been going on with the Deep Roots project.

Here in Liverpool, we have all the artefacts excavated from sites around Victoria Falls (see 2017 and 2018 blog posts) and most recently at Kalambo Falls (2019).  There are thousands of stone tools on temporary loan to be returned to Zambia once they’ve been analysed.

A key aim of our research is to understand the changes – and continuities – in the ways tools were made and used over a period we call the Early Stone Age (Acheulean) to Middle Stone Age transition.  Finding clues to when and why the changes took place is also part of the project’s aims. 

Excavation bags from the 2017 Deep Roots season at Victoria Falls in the Lithics Lab, University of Liverpool

For now, the focus is on the large stone tools of the Acheulean and Sangoan (a transitional phase preceding the Middle Stone Age) and understanding how they were made.  These include tools labelled as ‘handaxes’, ‘cleavers’ and ‘core-axes’. There’s a lot of variability obscured by these labels – but that’s another story for another time.   

Modern technology comes to our aid in reconstructing the making of these early tools.  In the labs at Liverpool we are building 3D models of them using structured light scanners, then applying imaging software to highlight the steps involved in shaping the tools. 

These large tools, like the core-axe, are made by removing flakes with a stone hammer to outline the general form and then smaller removals to refine the form, sometime using hammers of softer stone, wood or bone.  The imaging software makes it easier to illustrate the sequence by colour-coding the removals from first to last. 

A core-axe (or as we now call them, ‘core-adzes’) from Victoria Falls, in profile, showing the unusual shape of this large tool

That work is underway with the help of our photographic team, training students – and me – in the use of the scanner, the software and in techniques of photogrammetry to create 3D models using multiple photographic images. 

I’ve asked Hanna Crosby, a second-year student to share her experience in learning to use these imaging tools as part of the Deep Roots project:

“My first day working on the Deep Roots project was spent familiarising myself with the 3D scanner and the tools themselves. It is amazing to see the process of transformation from an object you can hold in your hands to an accurate 3D model that shows each feature of the original artefact. Through the methodical capturing of images from a variety of angles, a model can be built that has a very high fidelity to the real artefact. The tools themselves represent a fascinating wealth of knowledge and information that, through the scanning and modelling process, can be safely preserved and studied. After scanning a number of medium-sized tools, including cleavers, points and handaxes, we attempted to capture images of increasingly small artefacts. These included finely worked points and tiny blade fragments. Capturing images for these models required us to adapt the scanning process to capture the small artefact images more accurately, which we achieved by bringing the tool closer to the scanner and altering its position using a foam mount.

Scanning the smallest tools required adapting and improvising. Some were so small that they required an alternative scanning method, so I employed photogrammetry methods to capture the images for those models. It was interesting to test the bounds of the scanning device, understanding what it struggled to capture and finding ways to counter this. Working with the scanner gave me a greater understanding of the importance of time and purpose on projects, as part of my focus was balancing the amount of time it took to capture a scan with the quality of the 3D model produced.

During the course of my internship, I learned a huge amount about not just the capturing of the images, but about the entire 3D modelling process. I am certain that, as technology progresses further, this knowledge will become increasingly relevant to the fields of archaeology and heritage.”

Hannah’s final point about heritage is important.  This project is creating an archive that will be available to anyone interested in accessing the data we generate.  The Deep Roots project is funded by the taxpayer who has the right to access this information, including the photos, for years to come.

About Larry Barham

My name is Larry (Lawrence if I’m feeling formal) Barham and I'm a Professor of African Archaeology at the University of Liverpool, England, teaching evolutionary anthropology at undergraduate and postgraduate level.