Indigenous rock art is among the oldest extant artwork in the world. Rock art has great significance to the culture and self-understanding of indigenous people. It is also a highly valuable tool in understanding archeology and anthropology. Recognising this importance CSIRO has developed two scientific processes to help preserve this artistic piece of history.
The scientific processes of spectrophotometry and reflectance spectroscopy were applied to determine if any changes had occurred in colour, contrast or chemical composition. Spectrophotometry is a recognized way of recording the colour of a surface or material using an internationally accepted numerical system known as CIE Chromaticity Coordinates. Reflectance Spectroscopy is a technique which analyses reflected light in the visible-to-shortwave infrared wavelength range and offers a quantitative analysis of many geological materials.
In recent years, concerns have been raised regarding the dust emissions of mining companies and whether they could be altering the physical state of ancient rock art. A series of tests were conducted to determine the chemical composition of the dust particles in the rock art region and compared to that of nearby industrial sites. No iron-ore fragments were found in the vicinity of the rock art.
However, due to the importance of these sites, a research team was also commissioned to carefully evaluate the possibility of any future risks that may occur in the long term. Not only were the rock surfaces tested for pollutants, but the micro-organisms were also tested to assess if they incurred any changes.
The initial four-year study that was conducted along the Burrup Peninsula, concluded that no significant changes occurred during that period. This study was then taken as a benchmark of analysis for all future studies. CSIRO conducts regular assessments based on these benchmark figures to determine if any changes do occur.
Other similar methods adopt the technique of using a physiochemical approach to improve preservation techniques. The use of spectrographs (pictures produced through instruments that measure light) and chromatography (measurements of absorbency) have often been applied to reproduce and renew traditional coloring techniques.
Scientists at the Faculty of Fine Arts of the University of Marmara in Istanbul are experimenting with ancient coloring methods–by altering the amount of organic compounds, temperature or dissolving time–to produce pigments identical to those historically used.
Modern, scientific approaches can have a significant role to play in analyzing, protecting and restoring significant ancient artifacts.
Original Source: CSIRO Earthmatters, Issue 20, Jul/Aug 2009