Stone-flaking ‘spandrels’ experiment, Video 1: Flake removals - Dr Mark Moore

The ‘spandrels’ experiments explore complexity in the stone tools made by our earliest hominin ancestors. They aim to test whether the stone tool types identified by archaeologists are complex ‘designed’ tools, or whether these objects might have been produced by undirected stone flaking. The experiments aid our understanding of the cognitive abilities of our earliest tool-making ancestors. The results of the first round of experiments were published in the open-source journal PLoS One (Moore and Perston 2016, 11(7) e0158803). The formal experiments were done in the lab; I taped these videos outside my shed to illustrate the process, using a Gopro camera mounted to my chest. This video shows just the flake removals, not the note-taking. Not shown is the process of labeling all of the possible striking platforms on the stone, selecting one randomly, and drawing the predicted outline of the flake with a permanent marker. Copper hammers are used because stone hammers tend to shatter and would need to be replaced, leading to inconsistency between experiments. The cobble in the video is Australian silcrete, a form of quartzite, and it weighed 18 kg. Unusually, only one potential platform could be identified on the unmodified stone because it was so rounded. Blow 1 opened the cobble; the tapping is necessary sometimes to get the fracture surfaces to separate in this coarse material. I can usually tell by the sound whether the crack has propagated. Platforms began proliferating from this point in the experiment. The rounded back of the cobble continued to be unsuitable for platforms through most of this experiment, so flakes were struck repeatedly from along the flaked edge. Blow 5 propagated down the edge of the core, removing every identified platform, but creating an equal number of new ones. By Blow 7, the core developed a ‘chopper’ morphology, with a bifacial edge opposite a cortical surface, and grew quite elongated. Blow 10 illustrates one of the problems of using copper-it deforms on impact, absorbing some of the force, and multiple strikes are often necessary to initiate the crack. Blows 12, 13, and 15 lop off the ends of the elongated core, along with most of the rounded part of the cobble. Blow 19 removed much of the core face. The core weighed 1.9 kilos after Blow 19, and I elected to end the experiment at that point. The formal experiments would have continued until the core dropped below 400 grams. The core throughout this experiment retained that bifacial ‘chopper’ morphology, but two platforms were identified at distal ends of scars after Blow 18, and if they were selected by the random number generator, the core would transition to multiplatform. This commonly occurred late in the experiments.

[@robbmg9716]

Thank you for the great videos. :)
It's amazing how you can predict the flaking with such accuracy.