Environment & Science Writer
ARCHAEOLOGIST Steven Walker gently holds a stone tool unearthed from an excavation in the floor of an overhang deep in the Cederberg mountains, near the Pakhuis Pass.
Although this particular tool hasn’t been formally dated, Walker and his colleagues think it dates from 100 000 years ago, and that since being lost or discarded this is the first time it’s been touched by a human hand again.
“That’s pretty cool, don’t you think?” he suggests.
Walker is part of a small research team headed by Dr Alex Mackay who are working on this site at Klipfonteinrand, a property that is part of the Bushmans Kloof Wilderness Reserve and Retreat.
Mackay is an Australian archaeologist who has worked extensively on sites in the Western Cape through an association with UCT’s archaeology department, and who specialises in stone tools from the Middle Stone Age – the period stretching from about 200 000 to 30 000 years ago in which modern humans appeared and began to act in distinct ways.
Because of the importance of these local sites to the history of the emergence of modern human beings and their migration from Africa to the rest of the world, Mackay – a post-doctoral research fellow at the Australian National University in Canberra – obtained a grant from the Australian Research Council to excavate Klipfonteinrand.
His team dug there earlier this year and returned for another month. Already, they have recovered 10 000 artefacts.
Mackay says UCT archaeologist professor John Parkington had first excavated this site in 1969. Parkington was interested in the archaeological history of the last few thousand years and, although he discovered and excavated a burial site, he hadn’t really found what he was looking for, Mackay says.
“When we came back, we started by taking out John’s old hole to give us the best idea of what would happen. It was quite a mission after 42 years, but we got there and identified that part of it that we thought would work best for us.”
They’ve subsequently excavated 3m2 and have found a marked discontinuity in the age of the sediments from about 12 000 years until about 55 000 to 65 0000 years, then a further gap after that.
“From where we are now at the bottom, it’s hard to say, but it will probably be in the range of 100 000 to 120 000 years. So I think we’re quite a long way back in time and there’s lots of archaeology coming up.”
Artefacts recovered here include beautiful unifacial rock points, which are “a classic marker” of the era between 55 000 and 60 000 years ago, pieces of ochre that are probably from the same time, and cores – rocks from which flakes were struck – dating from more than 75 000 years.
but this particular excavation has been adversely affected by natural water run-off. “Water isn’t good for archaeology. Where you put moisture into organic-rich sediments, you attract roots, and roots move down into the sediment and break it up, and so you generally lose the bones that would have been there,” says Mackay.
The team has also opened a new 2m2 excavation in drier sediments at the back of the shelter, where they have found well-defined laminations, or stratigraphy, in the sediments.
“There’s quite a dramatic contrast between what we have here and the front of the shelter. Based on the artefacts, I would guess that the finely laminated stuff at the top is about 8 000 to 12 000 years, and in a lower part it’s pushing past 14 000 to maybe 18 000 years.”
Two of the team, Wesley Flear and Kyla Bluff, are each day finding up to 100 artefacts from just 3cm of sediment that they are removing.
“That’s rich,” he says. “And it’s an interesting age, because 14 000 to 18 000 years ago the world was extremely cool, the coldest part of the last 120 000 years, so that changes everything around here. There may have been much less fynbos and we suspect it was Afromontane forest. So you can imagine really quite different landscapes that these people were inhabiting.”
Artefacts include ostrich eggshell, an abundance of stone tools, and bone – one of them a beautiful tortoise humerus that is probably about 18 000 years old.
Partly based on Parkington’s 1969 field notes, they suspect this deposit at the back of the shelter may be as much as just more than 3m deep and probably still substantially intact. If that proves correct, it could take them into an era older than 90 000 years.
“I’m excited. Once you get back past about 80 000 years you’re in interesting territory,” says Mackay. “And when you get back to about 100 000 years, you’re talking about the big human question, the ‘Big Picture’– it’s part of a history that has relevance to everyone, everywhere, which is why someone like me from Australia is fascinated by these questions.”
Anatomically modern humans emerged about 200 000 years ago, but the emigration pulses from Africa into west Asia, Australia and Europe occurred only during the last 100 000 years, according to available evidence, Mackay explains. “Why would it take them 100 000 years to get to that point where they suddenly decide that world domination is the game for them?
“Because that’s what seems to have happened. And the reason why these questions remain relevant here at the southern tip of Africa is because there are quite special sites with these sequences (different age layers) where we can see the kinds of things people are doing within that time range, and maybe start to answer these questions.”
The Cederberg and adjoining areas across the Sandveld and down to the coast at Verlorenvlei and Elands Bay are blessed with just such sites,.
l John Yeld was the guest of Bushmans Kloof Wilderness Reserve.