Among points examined, 29 out of 104 had ochre residues on them, 30 out of 83 scrapers had ochre on them, 23 out of 77 pieces of "other" retouch had ochre and 26 out of 113 flakes had ochre on them.
Encouraged by these results, which strongly suggest that ochre residues are most likely to be found on the bases of retouched tools like points, it was decided to explore this conclusion further.
Ochre traces were then examined, and were documented as concentrated on the proximal and medial portion, on the distal portion or all over.
The c values make it clear that the most significant concentrations of ochre (58 per cent) are, in fact, on the medial portions of the whole points.
Microscopy study 1 showed that ochre is often associated with plant derived residues such as plant tissue, starch, white starchy deposit which appears to be cooked starch, resin and plant exudate and often these plant-derived residues are coincident (Table 1).
More plant tissue and starch was found on the tools that have ochre than on those that do not, but, with the exception of the scraper and flake categories, there is a tendency for more resin to occur on tools that do not have ochre on them.
The position of ochre on the tools is considered extremely important for the study at hand.
An explanation for why ochre would have been used in the process of hafting tools seems to come from experimental work conducted in France.
Recent replication studies by one of us (LW) confirm that the heating of an ochre and plant resin paste is appropriate when attempting to set a stone tool into a wooden shaft.
Some of the Sibudu stone tools do appear to have resin or mastic mixed with their ochre residues, but not all do.
This Sibudu Cave residue study suggests that ochre found on MSA tools resulted from at least two activities.
In Kenya, backed blades from Enkapune Ya Muto, dated to between 50 000 and 40 000 BP, have red ochre residues on their backed portions (Ambrose 1998).