Extending the history of digital humanities by 510 million years
By rmapapg, on 30 March 2022
UCLDH was fortunate to be awarded funds through UKRI’s Research Capital Investment Fund in 2019 in a bid led by our previous director Prof Simon Mahony. The bid funded the purchase of a Bruker Tornado M4+ x-ray fluorescence scanner. This is a unique system that uses x-rays to excite the atoms making up a substance which then emit x-rays that are characteristic of the elements making up the sample. The beam is narrow and scans across an object, allowing an image to be built up of the elemental composition. It is situated in the UCLDH Digitisation Suite, with radiation safety provided by the Department of Medical Physics and Biomedical Engineering.
The system was delivered in February 2020. Events then conspired to delay its commissioning until Summer 2021. It is now fully functional and we are familiarising ourselves with its performance. Importantly, the system is capable of running under a vacuum which allows lighter elements to be detected than is possible with other similar systems. We are in the process of installing a helium pump which will mean we can image objects containing light elements without needing a vacuum. This is important for many objects of relevance to DH including paper and parchment documents which can be damaged by a vacuum.
We were approached by colleagues at the Natural History Museum who had prepared a paper describing a new fossil that needed an image of the elemental composition, exactly what this system can provide. The fossil was of a edrioasteroid, a relative of starfish and sea urchins. With the help of Tobias Salge from the Museum, we scanned the fossil overnight. The x-ray scans supported their other analysis, which showed that its skeleton was partially mineralised and partly soft. Its ancestors had had fully mineralised skeletons which mean that this was the earliest example of an organism that had lost a previously mineralised skeleton. The x-ray fluorescence imaging was able to show that some elements (phosphorus and calcium) were enriched throughout the fossil, but others (iron, zinc and silicon) were enriched only in the hardened regions, suggesting a different elemental composition in life.
This was an exciting departure for a system that was purchased to support research in DH, but imaging this fossil was too good an opportunity to miss. The work has been published in the Proceedings of Royal Society B:
Zamora Samuel, Rahman Imran A., Sumrall Colin D., Gibson Adam P. and Thompson Jeffrey R. (2022) Cambrian edrioasteroid reveals new mechanism for secondary reduction of the skeleton in echinoderms Proc. R. Soc. B. 289: 20212733 http://doi.org/10.1098/rspb.2021.2733