As far as the implements from Olduvai are concerned, if the angle being measured was the angle used by Barnes, or an equivalent angle, then the Oldowan industry, although universally accepted, does not meet the Barnes criterion. Considering the extremely crude nature of the objects, which Louis Leakey said were comparable to Moir’s implements, it is remarkable that they have never been subjected to the slightest challenge by the scientific community. This is probably because the Oldowan industry offers support to the African evolution hypothesis of human origins, which is accepted as dogma.
During the 1950s, the Barnes method was criticized by George F. Carter, who had discovered crude stone implements at various sites in the San Diego area, principally at Texas Street. The tools, mostly pebble choppers and quartzite flakes, were referred to the last interglacial. They were assigned dates of about 100,000 years, which violates the currently accepted idea that humans entered the Americas no more than 30,000 years ago, with most authorities adhering to a more conservative figure of approximately 12,000 years.
Reacting to attempts to dismiss the tools by the same methods used to reject the European eoliths, Carter (1957, p. 323) stated: “Comparison of the San Diego County material with that of Europe has severe limitations placed upon it that seem to have been missed by some people. The lithic materials are extremely different—quartzite and porphyries in California versus glassy rocks of the flint family in Europe. There is no frost action of solifluction or any related phenomenon in the San Diego area now nor was there any during the Pleistocene. There is no limestone area to founder and produce pressures.”
Specifically referring to the Barnes method, Carter (1957, p. 329) noted: “Clearly, many of the usual criteria for judging the human authorship of stonework do not apply to such a tradition. Regrettably this seems to apply especially to the platform-angles method of testing which was so useful in distinguishing between human and natural work in England. Barnes’ (1939) platform-angles on a bifacially flaked tool are much lower than 90 degrees. Those on flakes and cores of an industry such as that of Texas Street are normally about 90 degrees. It should not be overlooked that plano-convex tools normally have high platform angles.” Plano-convex tools are those that are flat on one side and convex on the other. So here we have another example of an industry that was accepted (at least by Carter and his supporters) as being of human manufacture and that does not conform to the Barnes criterion.
In the preceding paragraphs, we have reviewed a number of stone tool industries that appear to be exceptions to the criterion proposed by Barnes. If these industries can be considered exceptions, then why not any or all of the various Eolithic industries that Barnes rejected?
Leland W. Patterson, the principal author of a recent study on the stone implements discovered at the Calico site in California, has also examined the application of the Barnes method. At Calico, stone objects believed to be of human manufacture have been found in strata dated by uranium series analysis to about 200,000 years before the present. They are, therefore, like the Texas Street implements, highly anomalous. We shall discuss these and similar finds relating to the human settlement of the Americas more fully in Section 3.8. For now, we shall confine ourselves to studying the application of the Barnes method to the Calico specimens, which are quite similar to Eolithic implements.
Barnes angle measurements were used by L. A. Payen (1982) to dismiss the Calico specimens. But L. Patterson and his coauthors (1987, p. 92) believed that measurement of Barnes’s angle was not suitable for this purpose. Patterson defined the Barnes angle, or beta angle (Figure 3.26), as “the angle between the ventral surface and the platform plane” (L. Patterson
Patterson observed: “For general lithic analysis, the striking platform angle is a better attribute than the ‘beta’ angle . . . because prominent bulbs of force on ventral surfaces of flakes can frequently interfere with ‘beta’angle measurement” (L. Patterson 1983, p. 301).
When Patterson and his coworkers measured striking platform angles rather than beta angles, their results differed from Payen’s: “Acute platform angles were found on 94.3% of the Calico flakes with intact platforms as compared with 95.5% of the experimental sample. The average platform angle of the Calico flakes was 78.7%, with a standard deviation of 8.3%. This is consistent with the usual products of intentional flaking” (L. Patterson