The objects, dated to at least 70,000 years ago, were recovered from the Middle Stone Age layers at Blombos Cave, a site on the southern Cape shore of the Indian Ocean
I am an artist, my knowledge of archaeology is minimal. However I have a speculation about the objects of ochre found at Blombos Cave that you may find of interest.
I think that the object is not a rock with an image on it, but a tool. My reason for thinking this, is that the objects look like the way I would cut a piece of ochre if I wanted to evenly cover a soft wet or damp material with an even surface of pigment. As I did as a student learning about old techniques in printing.
The cuts in the ochre are like the tracks on a tyre. If you tried to rub the surface of a wet material with a flat piece of pigment, the pigment unless it is of the highest quality will break off, not all as powder, but some will come off as grains and this would produce small lumps which would stop the pigment from evenly coating the surface of the material, also as you rub the pigment across the surface you would get build up of rubbed off pigment around the edges of the ochre. This would mean that the wet surface would not be evenly covered with the pigment, but that there would be smears of pigment on the surface some thick some thin, and it would be hard to avoid there being spots which were not covered at all.
Now you may think of Pastels or chalk drawings, but there is a difference in that the object I think would have been used on wet surfaces. Pastels need no grooves because being dry the artist can blow any build up away from the image, but the pigment from the ochre in contact with a wet surface would be sticky and hard to remove or even out.
However if groves are cut in the pigment the build up of loose bits which have rubbed off are evenly distributed not just at the edges of the ochre, but also evenly in the groves cut into it, meaning the ochre remains in tighter contact with the wet material, a more even rub off of the pigment and thus an evenly covered surface of the damp material.
Knowing that a simple way of tanning the skins of animals is to apply an even surface of ochre, I think this would be a much stronger explanation of what the object is than a nice picture.
I would also point out it is not the sort of image a human would first make. All children across the world develop drawing skills in the same way. They first learn to make marks which are identifiable as objects or people, it is only later they become interested in pattern. Consequently I have to speculate the patterns carved into the ochre are not the first drawings. The consistency of the pattern needed to make this tool depicts an ability to remember and inscribe the pattern which I would say shows its maker as already having the ability to make and remember images.
Looking at the pattern it does not look to me like the maker was particularly interested in making triangular, or diamond patterns, but rather is driven to make all the grooves of the right angle. You will notice how all the grooves are so parallel to each other. Which would aid the even distribution of worn off pigment from the ochre.
The presence of ochre with the dead as depicted in the archaeology would make perfect sense when we think of the pigment being used to preserve skins, the ochre would be seen as a means of preservation.
Lastly I personally think whether this ochre is a drawing or a tool is important. If it is an image it is not well crafted, and would depict a people with rudimentary skills, alternately if it is a tool you can see how well it is crafted for its purpose, and it is not just a tool to achieve an objective, but a tool to make something else; to tan a skin, then what would they have used the skin for? We can only speculate how good craftspeople they might have been.
that's my speculation I would like to know what you think.
Link to conventional explanation of the objects.
http://www.nsf.gov/od/lpa/news/02/pr0202.htm
