Student Spotlight: Nikola Ristovski
Nikola is a full-time Honours student applying geophysical techniques (mainly Fourier Transform Infrared Spectroscopy, a method of fingerprinting materials based on absorbance of infrared light) to fragments of bone and clay to better understand Indigenous fire practices.
Evidence of fire is frequent in the archaeological record, but the further back you look, the more ambiguous its nature becomes. My thesis considers the potential of microarchaeological techniques like infrared spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) to determine the heating temperature of archaeological bone and clay.
This can increase the resolution of fire-related data and allow us to better identify and understand Indigenous fire practices where evidence is scarce or complex.
Left: microscopic surface of fish vertebra heated to 600°C; Centre: Calcined fish bone, part of my reference collection; Right: Fragments of archaeological bone and teeth from Boodie Cave suspended in resin and viewed under a microscope.
While more and more researchers are becoming privy to these techniques, they are rare in Australian archaeology which has a specific need to resolve subtle, deep-time stratigraphy. FTIR and XRD work great alongside the microscopic study of undisturbed sediments (known as micromorphology), and can sometimes be applied directly to these microscopic slides to better understand spatial relationships between differentially heated artefacts and how they change through time.
I am first building a reference collection of heated bone from local species that includes grey kangaroo, emu, snapper and turtle, then analysing the changes to colour, surface morphology, and infrared spectra as the samples are exposed to incrementally higher temperatures, reminiscent of human uses like cooking, controlled burns and natural bushfires. I’ll then apply this local reference collection to real archaeological material from Boodie Cave (an Aboriginal rockshelter on Barrow Island, NW Australia, occupied as early as 50,000 years ago) to test the potential of these techniques in archaeology and analyse how fire use has changed through time.