Accelerator Radiocarbon Dating of Natal Drakensberg Paintings: Results and Implications

Article excerpt

Introduction

The Natal Drakensberg, situated in the KwaZulu-Natal province of South Africa, is endowed with a large rock-art heritage. Around 30,000 individually painted images have already been recorded (Mazel 1984a) in some 570 rock-shelters. These rock-paintings have been the subject of considerable research during the past century, especially in the last 40 years (see e.g. Lewis-Williams 1981; Pager 1971; Vinnicombe 1976; Willcox 1956).

Other archaeological research in the area has focused on the excavation of rock-shelters. The most recent, by Mazel (1984b; 1989; 1990; 1992) and Cable (1984), has led to the construction of a relatively well-informed picture of hunter-gatherer history in the Natal Drakensberg which, for the most part, dates from about 8000 years ago.

A problem confronting archaeologists in this area, as elsewhere, has been their inability effectively to integrate the information derived from excavations with that from the rock-art. This has been largely due to the inability to date the majority of paintings, and thereby to place them into a chronological context derived from dating charcoal from layers of deposit. Attempts have been made to date the Natal [TABULAR DATA FOR TABLE 1 OMITTED] Drakensberg paintings directly through paper chromatographic dating (Denninger 1971) and by direct radiocarbon dating (van der Merwe et al. 1987). The paper chromatographic dates are considered unreliable (Rudner 1989), while the initial radiocarbon attempts were unsuccessful.

Recent advances in the direct dating of rock-paintings through radiocarbon AMS dating have made it possible to establish a joint project in the Natal Drakensberg (Watchman 1993). To this end, 10 paint samples were collected in the Cathedral Peak and Monks Cowl areas of the northern Natal Drakensberg in November 1993 for analysis and dating.

This paper reports on the 10 samples and the first direct dating of rock paintings in the Natal Drakensberg. It briefly comments on some of the implications.

Dating

Binocular and petrographic observations to identify minerals, and scanning electron microscopy energy dispersive analyses to determine the presence of carbon and other elements, reveal an assemblage of three paint types: calcite and quartz; gypsum-based paint with accessory quartz and clay and either haematite or magnetite, and quartz and feldspar (TABLE 1). Calcite and quartz paint mixtures at Clarke's Shelter are white, without colourant, and red because haematite was added. Gypsum-based paints range from almost pure gypsum to colouring additions of magnetite (black), clay (mauve/lilac and white), haematite (orange to red) and oxalate (maroon). While the sources of these colouring agents are unknown it is interesting to speculate, although uncertain because of inconclusive analyses, that the maroon-coloured paints at Junction Shelter may owe their colour to the presence of carbon-bearing compounds possibly derived from carbon media or binders.

Finding magnetite, clay, haematite, calcite and feldspar in the paints may possibly reflect selection of these natural earth colourants and extenders from different locations rather than from a single source. These components, once mixed with gypsum, formed relatively thick paints that were probably applied as thick slurries. It seems more likely that gypsum crystals were added to increase paint volume; they are aligned sub-parallel to brush strokes, which suggests that the large crystals were an integral component of the paint. Growth of gypsum as an efflorescent alteration product is more likely to occur at right angles to the painted surface than to the direction of brushing. Clear gypsum crystals up to 0.7 mm in length exist in the orange and white paints at Esikolweni and Nkosazana Shelters, respectively, implying that crystalline gypsum was either present in the natural earth material and was not ground before being used as a paint, or it was formed in situ through post-painting reaction. …