Okay! Ready for another visit down the Wonderwerk Cave rabbit hole? Keep in mind the main points of Berna et al.’s paper claiming million-year-old fire use at Wonderwerk. First, lots of burnt stuff–animal bone, grass, ash. Second, no bat guano ’cause there wasn’t any Berlinite in the deposits [long story, that]. Their conclusion: no spontaneous combustion. That leaves Homo erectus [or a reasonable facsimile] as the only actor that could have been responsible for the fires in the cave. And Berna et al. report that the senior archaeologist, Beaumont, ‘reported macroscopic evidence for burning.’
I had to see what he had to say. So I’ve collected the pertinent portions of
‘The Edge: More on Fire-Making by about 1.7 Million Years Ago at Wonderwerk Cave in South Africa,’ by Peter B. Beaumont (Current Anthropology, 52, 585-595, 2011).
I call Wonderwerk Cave a rabbit hole mostly because the logic of what’s been claimed can be a little hard to follow [to say nothing of ‘swallow’].
the cave was exploited for “agricultural fertilizer” between 1940 and 1944, when the cave interior was largely dug out to a depth of up to 2.5 m
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Here’s a link to the full-sized version on my Flickr account. |
A 40 lb (~22 kg) bag of fertilizer works out to about 40 litres. A cubic metre contains 1000 litres (doh!). So, those 375 cubic metres removed from Wonderwerk would have yielded about 9,375 bags of fertilizer. That’s a lot of dirt! That’s a lot of labour, too. Yet, as you’ll discover a little further down, Beaumont surmises that there can’t have been much in the way of effective fertilizer in the dirt the diggers removed. Keep that in mind as we work through the rest of Beaumont’s ‘observations’ on Wonderwerk Cave.
Zoological studies at regional bat caves show that all have dark interiors, little or no air movement, and relatively high humidity levels; the only place in Wonderwerk that partly matches those conditions is a deep roof cavity at its rear, where a small number of bats were seen in 1988, briefly replacing the barn owls that usually reside there…
As for bat dung/guano, this was originally linked to the red sand strata …, a claim not supported by a study of the sediments …, which showed that all levels are mainly (>90%) made up of sand and roof fragments, or by the finding that the microfauna indicates a preponderant avian occupation of the cave by barn owls…, with only modest amounts of bat guano likely confined to lenses below the roof cavity near the back wall.
Second, does he think that bat guano fossilizes? Well, if he does, he’s very wrong. It decomposes like any excrement, leaving phosphate minerals. Thus, if at present it’s invisible in the cave sediments we should expect nothing less. And until Berna et al. publish the complete list of phosphate minerals they did find in the cave, we’re left in the dark as to the likelihood that bats ever left much behind in the cave [that wasn’t mined by ‘diggers’ that is].
Lastly, it’s laughable when the author asserts that bat guano would have accumulated only where bats have been observed to roost in the cave in the past hundred years. We’re talking about a MILLION years, fer gawd’ sake! Beaumont must be the most extreme proponent of uniformitarianism that ever set foot in a palaeontological locality!
From these data it is evident that the 1940–1944 diggers were marketing a product that contained little in the way of fertilizer
If so, they must have been running a con. And, if it was a con, this might be the only time in criminal history that such a gambit involved hard labour on the part of the grifter! Hey. Maybe not! Maybe the cons were so good at their game that they did a Tom Sawyer on some unsuspecting yokels, and had them dig out half the cave!
Please, make your own conclusions. I’m happy to hear your reasons why anyone should accept Beaumont’s assertions at face value.
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