Graffiti Threatens Proof of Ancient Life On South Africa's Coast

Surfaces like rocky outcrops that dot much of South Africa's coastline are of profound scientific, cultural, heritage, environmental, and aesthetic importance. These cemented remains, or aeolianites, and the tracksites they contain, provide a snapshot of the Pleistocene Epoch, which started around 2.6 million years ago and lasted until about 11,700 years ago. Unfortunately, they are threatened by graffiti. Their fairly soft, friable nature means that with nothing more than a hammer and a chisel, names and other images can be etched into them. That poses a tremendous risk to the underlying scientific information contained in these rocks' surfaces, writes Charles Helm for The Conversation.