Conservation of Rock Art. Proceedings of the International Workshop on the Conservation of Rock Art, Perth, September 1977 (1978), pp. 36-41
Reports on some of the findings of a recently completed study of the geomorphological histories of a number of sandstone shelter archaeological sites in Southern New South Wales. Average natural rates of cavernous weathering in these shelters was demonstrated to have been slow, on the order of 0.1-0.5 mm per 100 years, with granular disintegration and small-scale flaking being the main process at work. Man was shown to have greatly accelerated cavernous weathering and roof-fall by dislodging weathered rock and hence exposing fresh rock surfaces to further weathering, and by influencing the shelter environment through changes in temperature and humidity. Since abandonment, crusts of weathered rock have again formed on the roof and walls of most shelters and contemporary rates of weathering and roof-fall are again slow. The significance of cavernous weathering of such sandstone shelters for the age and deterioration of rock art are considered and plans to monitor sandstone weathering in a range of environments over a long time-span are outlined.