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3.4.8 Barnes and the Platform Angle Controversy

Another important element in the eolith controversy was the platform angle test, promoted by Alfred S. Barnes. Barnes, who defended Moir against attacks by Haward and Warren in the 1920s, later became opposed. In 1939, he delivered what many authorities still regard as the death blow to the Red Crag and Cromer Forest Bed tools. But Barnes did not limit his attention to East Anglia. In his study, titled “The Differences Between Natural and Human Flaking on Prehistoric Flint Implements,” Barnes (1939, p. 99) considered stone tool industries from France, Portugal, Belgium, and Argentina, as well as those of Moir.

Supporters of the view that implements from the above sites were of human manufacture generally argued that natural forces could not produce the kinds of chipping observed on the objects in question. Barnes admitted that random concussion would not produce effects such as regular, unidirectional chipping along a single edge. He also felt that simple pressure from overlying beds, as proposed by Breuil (Section 3.4.1), was also not a very satisfactory agent, because it did not produce specimens with good striking platforms or clearly marked bulbs of percussion (Barnes 1939, pp. 106–107). But Barnes went on to give some examples of natural forces that, in his opinion, were capable of producing objects resembling eoliths. He called attention to some flints collected from the Blackheath Eocene marine beds at Stanstead in Surrey. At this site, by a process called foundering, flint nodules had descended 20 to 40 feet into cavities eroded in the chalk, where they were crushed by masses of large pebbles from the overlying beds. Some chipped flints were found lying in contact with the parent blocks (Barnes 1939, p. 103).

Besides foundering, another natural force that could, according to Barnes (1939, p. 106) and others, produce eolithlike specimens was solifluction, in which a large mass of frozen gravel thaws and then flows rapidly down a slope.

Barnes admitted that judgements based on simple visual inspection of chipping thought to have been caused by foundering or solifluction were liable to be very subjective. So he proposed that attention should be focused on some measurable feature of the implements that could be objectively evaluated. For this purpose, Barnes chose what he called the “angle platform-scar.”

Barnes (1939, p. 107) explained: “It may be said of natural fractures in general that some really good pseudomorphs of human work may be found, but when a number of specimens are examined, examples of aberrant flaking will be present. These aberrant flakes either serve no useful purpose in connection with the supposed tool or occur in positions where they would not be found in human work, or present angles platform-scar which are obtuse. The angle platform-scar is the angle between the platform or surface on which the blow was struck or the pressure was applied which detached the flake, and the scar left on the tool where the flake has been detached.”

We find Barnes’s description of the angle to be measured somewhat ambiguous. We have spoken with experts in lithic technology at the San Bernardino County Museum, including Ruth D. Simpson, and they have also been unable to specify exactly what angle Barnes was measuring.

In any case, in the angle platform-scar, Barnes believed he had found the objectively measurable feature by which one could distinguish natural chipping from human work. However, as noted later in this section, modern authorities such as Leland W. Patterson have extensively critiqued Barnes’s methodology.

Barnes (1939, p. 109) made these observations: “When we examine the tools of Paleolithic man we find that they are furnished with acute edges (less than 90 degrees) for cutting and scraping, for such edges are more effective for these purposes than edges with obtuse angles (90 degrees and over). There is a further reason why on humanly made tools