RESCUING THE AMMOGLYPH:

Over the past few years I have written two previous columns about Ammoglyphs (click on ammoglyph in the cloud index at the bottom of the page). This newly designated form of rock art consists of a design drawn in sand which then became covered with more sand instead of being erased or destroyed. This sand can become consolidated over time to sandstone and splitting open layers of sandstone may reveal the original design. Obviously, this requires a number of precarious things to take place for the design to survive the millennia, but this is exactly what happened on a South African beach.

The rescued boulder showing the preserved drawing in sand. Photograph by Charles Helm.

“Our own remarkable discovery happened on a rugged, remote stretch of coastline east of Still Bay on South Africa’s Cape south coast. It was low tide, and three members of our ichnology team (people who study tracks and traces) were in search of newly exposed Pleistocene vertebrate tracksites in aeolianites (cemented dunes). Ahead we saw a large rock that had tumbled down from the cliffs above. On its surface was a pattern of linear groove features in a large triangular shape, complete with an almost perfect bisecting groove. The sides of the triangle were close to a metre in length. After extensive research, we concluded that these grooves must have been made on a dune surface of unconsolidated sand by our human ancestors in the Middle Stone Age. The patterns are likely between 143,000 and 91,000 years old.” (Helm 2024)

Stilbaai (Still Bay) lies almost 400 kilometers east of Cape Town. Photograph from South African Tourism Board.

This remarkable discovery in South Africa opened our eyes to another entirely new category of rock art which they named ammoglyphs. Intentional marks made on sand later consolidated into sandstone and subsequently exposed again by natural forces like erosion. This makes that particular piece of beach in Still Bay on South Africa’s southern Cape coast the ‘type’ site for ammoglyphs, important indeed.

Boulder in the process of being rescued by helicopter. Photograph by Richard Webb.

“But there was a problem. On a follow-up visit we found a smaller rock close by with a similar triangular feature. Subsequently, it was destroyed, likely by storm surges or high tides buffeting and overturning it. We knew that the larger rock inevitably awaited a similar fate of we did nothing. From our perspective this is one of the most important rocks in the world: it takes us back to our roots as a species and indicates the kind of ‘proto-art’ we were capable of creating so long ago. So we staged and unusual mission: a ‘rescue operation designed to get the approximately 500 kilogram rock to safety – in a museum.” (Helm 2024)

"The rock has subsequently been encased and placed on exhibit, with interpretive text panels. It joins similar exhibits in the museum; the grooves were an example of an ammoglyph, a term we had coined to describe a pattern created by humans in sand that is now evident in rock that has become cemented and then re-exposed." (Helm 2024)

The boulder that had been proposed for relocation. Pat Canyon, Baca County, Colorado. Photograph Peter Faris, September 1986.

Thirty-five years ago there was a considerable amount of talk about Historical Tourism, and a small town in southeastern Colorado near Picture Canyon devised a plan to build a prehistory museum to attract tourists. They proposed to start by moving a petroglyph covered boulder from a ranch in the area to be one of their major displays. Now moving a petroglyph boulder to rescue it from destruction, and moving it for a profit motive are two entirely different things. I thought the museum idea was a great idea considering the large quantity of rock art in that area, but I was appalled at the thought of desecrating the rock art site for it. Luckily it never happened. What I heard was that they could not afford equipment big enough to handle the boulder. Luckily, in this South African example, they could arrange for the right equipment, and it was moved to save it – rescued.

REFERENCE:

Helm, Charles, and Jan Carlo De Vynck, 2024, Rock Stars: how a group of scientists in South Africa rescued a rare 500 kg chunk of human history, https://news.yahoo.com. Accessed online 24 May 2024.