The rocky outcrops that cover much of the South African coast contain hidden treasures: the cemented remains of the dune and beach surfaces that existed hundreds of thousands of years ago.
These cemented remains, or aeolianites, and the traces they contain provide a snapshot of the Pleistocene, which began about 2.6 million years ago and lasted until about 11,700 years ago. During this time, today’s Cape South coast of South Africa looked very different. Our research team has found more than 300 vertebrate animal tracks in these rock surfaces on a 350 km stretch of this coast. The oldest surfaces are around 400,000 years old and the youngest are around 35,000 years old.
Some of these discoveries had important implications for the paleo-environment. For example, the presence of giraffes in the region is only known by their tracks; This suggests that at least part of the landscape was savanna forests. Also, breeding sea turtles and crocodiles is only known by the tracks they have left. Their ancient presence suggests a warmer climate tens of thousands of years ago.
This time and area were of vital importance to humans as well. In a number of places, these rocky surfaces provide clues as to where and how our ancestors walked, jogged, searched, created pictures in the sand, or used stone tools.
These surfaces are of profound scientific, cultural, cultural, ecological and aesthetic significance. Unfortunately, they are threatened – by graffiti. Their fairly soft, crumbly nature means that nothing but a hammer and chisel can be used to engrave names and other images on them. This poses an enormous risk to the underlying scientific information contained in the surfaces of these rocks.
Unfortunately, the amount of this type of graffiti seems to be increasing, as my colleagues and I of the African Center for Coastal Paleoscience at Nelson Mandela University pointed out in a recent magazine article.
Legacy knocked off
That’s not to say it’s a completely new phenomenon. A terribly older example comes from the West Coast National Park, about 120 km outside of Cape Town. Here, hominin tracks known as “Eve’s Footprints” were only destroyed by graffiti. When researcher Dr. Dave Roberts discovered the tracks in the 1990s, had already been a graffiti artist there and barely avoided defacing the tracks.
The plate with the tracks was flown to the Iziko Museum in Cape Town to protect it from further vandalism.
As we have found in our work, the result in a small cave west of Knysna, a town on the South African Garden Route, was not so happy. Here, a mass of graffiti adorns a sloping cave floor that was once the surface of a dune, obscuring what can be seen of the tracks below. Tragically, there is evidence that this, too, could have been traces of hominin, but we cannot be certain.
The dune surfaces that our ancestors stepped on have been buried. Over time, they were cemented and eventually re-exposed on the coast. But today the descendants of these ancestral pioneers carve their initials into these surfaces without appreciating their globally significant value for the heritage.
Education and awareness
Fossil track sites appear to encourage the graffiti artist’s creative urge, as etched graffiti is more common on or next to such sites. How can this problem be addressed?
Education and general awareness are important to addressing the problem, and perhaps lessons can be learned from protecting rock art, which can also be defaced by graffiti. Signage at access points to coastal areas can be helpful, with catchphrases such as “Please do not destroy in five minutes what took 120,000 years”.
Or perhaps non-trace aeolianites (cemented dunes) can be placed at strategic access points and people can be allowed to carve their names on these surfaces if they so choose. With Aeolianites abundant in South African national parks and other protected areas, agencies such as SANParks and CapeNature may be well placed to lead such initiatives.
These Aeolianites are of vital international importance and, given their heritage, scientific and aesthetic value, a powerful argument can be made for their protection. It can be helpful to think of aeolianite surfaces as a kind of time capsule: these are the same dune surfaces that our ancestors saw and stepped on when they started thinking and acting like us.